reasons why the atomic bomb was necessary essay

The Decision to Drop the A-Bomb

Questioning why the U.S. dropped the a-bomb on Japan.

The chronology is always the easiest part. The U.S. detonated an atomic bomb over Hiroshima on August 6, 1945. The Soviet Union declared war on Japan on August 8th and then invaded Japanese-occupied Manchuria just after midnight. Later that day, August 9, a second U.S. a-bomb was dropped on Nagasaki. Japan surrendered on August 15th, with the formal signing of peace occurring on September 2nd. World War II was over. But history is about more than dates. The devil is in the interpretation of the details.

The decision to drop A-bombs on Japan has been controversial since so-called “revisionist” historians in the 1960s began to question the traditional view that it was necessary to use these new weapons to forestall a bloody Allied invasion of Japan.

But scholarly research doesn’t necessarily permeate the public consciousness. Twenty years ago, in anticipation of the 50th anniversary of the atomic bombings, traditionalist/revisionist views came to a fierce boil over a planned Smithsonian exhibit of the Enola Gay , the B-29 bomber that dropped the bomb on Hiroshima. As originally planned, the exhibition would have represented the new generation of historical scholarship, but it was cancelled due to pressure from veterans and politicians; a non-controversial exhibit went up in its place. Even self-described “conservative” historians were disappointed by that decision.

Gar Alperovitz , one of the founding revisionist historians, pointed out the problem at the time: the “rapidly expanding gap between what the expert scholarly community now knows and what the public has been taught.” There was, in addition, “America’s continued unwillingness to confront the fundamental questions about Hiroshima.”

Alperovitz’s synopsis of the evidence is eye-opening. For instance, he notes that the first “revisionist” was in fact the U.S. military: both the U.S. Strategic Bombing Survey and a long-classified study by the War Department cast doubt on the military effectiveness of the A-bombs as early as 1946. Also quoted here are notable U.S. and British military and political figures, including Eisenhower, questioning the decision in their memoirs long before historians did. The notion that the use of the A-bombs was believed to be necessary at the time is also profoundly undercut by documents showing the options that President Truman and his advisers had at hand and rejected.

The question is why did they reject those options and go atomic? All these years later, are we any more willing to confront the fundamental questions about Hiroshima and Nagasaki?

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The Atomic Bomb and the End of World War II

A Collection of Primary Sources

Updated National Security Archive Posting Marks 75th Anniversary of the Atomic Bombings of Japan and the End of World War II

Extensive Compilation of Primary Source Documents Explores Manhattan Project, Eisenhower’s Early Misgivings about First Nuclear Use, Curtis LeMay and the Firebombing of Tokyo, Debates over Japanese Surrender Terms, Atomic Targeting Decisions, and Lagging Awareness of Radiation Effects

Washington, D.C., August 4, 2020 –  To mark the 75th anniversary of the atomic bombings of Hiroshima and Nagasaki in August 1945, the National Security Archive is updating and reposting one of its most popular e-books of the past 25 years. 

While U.S. leaders hailed the bombings at the time and for many years afterwards for bringing the Pacific war to an end and saving untold thousands of American lives, that interpretation has since been seriously challenged.  Moreover, ethical questions have shrouded the bombings which caused terrible human losses and in succeeding decades fed a nuclear arms race with the Soviet Union and now Russia and others.

Three-quarters of a century on, Hiroshima and Nagasaki remain emblematic of the dangers and human costs of warfare, specifically the use of nuclear weapons.  Since these issues will be subjects of hot debate for many more years, the Archive has once again refreshed its compilation of declassified U.S. government documents and translated Japanese records that first appeared on these pages in 2005.

*    *    *    *    *

Introduction

By William Burr

The 75th anniversary of the atomic bombings of Hiroshima and Nagasaki in August 1945 is an occasion for sober reflection. In Japan and elsewhere around the world, each anniversary is observed with great solemnity. The bombings were the first time that nuclear weapons had been detonated in combat operations.  They caused terrible human losses and destruction at the time and more deaths and sickness in the years ahead from the radiation effects. And the U.S. bombings hastened the Soviet Union’s atomic bomb project and have fed a big-power nuclear arms race to this day. Thankfully, nuclear weapons have not been exploded in war since 1945, perhaps owing to the taboo against their use shaped by the dropping of the bombs on Japan. 

Along with the ethical issues involved in the use of atomic and other mass casualty weapons, why the bombs were dropped in the first place has been the subject of sometimes heated debate. As with all events in human history, interpretations vary and readings of primary sources can lead to different conclusions.  Thus, the extent to which the bombings contributed to the end of World War II or the beginning of the Cold War remain live issues.  A significant contested question is whether, under the weight of a U.S. blockade and massive conventional bombing, the Japanese were ready to surrender before the bombs were dropped.  Also still debated is the impact of the Soviet declaration of war and invasion of Manchuria, compared to the atomic bombings, on the Japanese decision to surrender. Counterfactual issues are also disputed, for example whether there were alternatives to the atomic bombings, or would the Japanese have surrendered had a demonstration of the bomb been used to produced shock and awe. Moreover, the role of an invasion of Japan in U.S. planning remains a matter of debate, with some arguing that the bombings spared many thousands of American lives that otherwise would have been lost in an invasion.

Those and other questions will be subjects of discussion well into the indefinite future. Interested readers will continue to absorb the fascinating historical literature on the subject.  Some will want to read declassified primary sources so they can further develop their own thinking about the issues. Toward that end, in 2005, at the time of the 60th anniversary of the bombings, staff at the National Security Archive compiled and scanned a significant number of declassified U.S. government documents to make them more widely available. The documents cover multiple aspects of the bombings and their context.  Also included, to give a wider perspective, were translations of Japanese documents not widely available before.  Since 2005, the collection has been updated. This latest iteration of the collection includes corrections, a few minor revisions, and updated footnotes to take into account recently published secondary literature.

2015 Update

August 4, 2015 – A few months after the atomic bombings of Hiroshima and Nagasaki, General Dwight D.  Eisenhower commented during a social occasion “how he had hoped that the war might have ended without our having to use the atomic bomb.” This virtually unknown evidence from the diary of Robert P. Meiklejohn, an assistant to Ambassador W. Averell Harriman, published for the first time today by the National Security Archive, confirms that the future President Eisenhower had early misgivings about the first use of atomic weapons by the United States. General George C. Marshall is the only high-level official whose contemporaneous (pre-Hiroshima) doubts about using the weapons against cities are on record.

On the 70th anniversary of the bombing of Hiroshima on August 6, 1945, the National Security Archive updates its 2005 publication of the most comprehensive on-line collection of declassified U.S. government documents on the first use of the atomic bomb and the end of the war in the Pacific. This update presents previously unpublished material and translations of difficult-to-find records. Included are documents on the early stages of the U.S. atomic bomb project, Army Air Force General  Curtis LeMay’s report  on the firebombing of Tokyo (March 1945), Secretary of War Henry  Stimson’s requests  for modification of unconditional surrender terms,  Soviet documents  relating to the events, excerpts from the Robert P. Meiklejohn diaries mentioned above, and selections from the diaries of Walter J. Brown, special assistant to Secretary of State James Byrnes.

The original 2005 posting included a wide range of material, including formerly top secret "Magic" summaries of intercepted Japanese communications and the first-ever full translations from the Japanese of accounts of high level meetings and discussions in Tokyo leading to the Emperor’s decision to surrender. Also documented are U.S. decisions to target Japanese cities, pre-Hiroshima petitions by scientists questioning the military use of the A-bomb, proposals for demonstrating the effects of the bomb, debates over whether to modify unconditional surrender terms, reports from the bombing missions of Hiroshima and Nagasaki, and belated top-level awareness of the radiation effects of atomic weapons.

The documents can help readers to make up their own minds about long-standing controversies such as whether the first use of atomic weapons was justified, whether President Harry S. Truman had alternatives to atomic attacks for ending the war, and what the impact of the Soviet declaration of war on Japan was. Since the 1960s, when the declassification of important sources began, historians have engaged in vigorous debate over the bomb and the end of World War II. Drawing on sources at the National Archives and the Library of Congress as well as Japanese materials, this electronic briefing book includes key documents that historians of the events have relied upon to present their findings and advance their interpretations.

The Atomic Bomb and the End of World War II: A Collection of Primary Sources

Seventy years ago this month, the United States dropped atomic bombs on Hiroshima and Nagasaki, the Soviet Union declared war on Japan, and the Japanese government surrendered to the United States and its allies. The nuclear age had truly begun with the first military use of atomic weapons. With the material that follows, the National Security Archive publishes the most comprehensive on-line collection to date of declassified U.S. government documents on the atomic bomb and the end of the war in the Pacific. Besides material from the files of the Manhattan Project, this collection includes formerly “Top Secret Ultra” summaries and translations of Japanese diplomatic cable traffic intercepted under the “Magic” program. Moreover, the collection includes for the first time translations from Japanese sources of high level meetings and discussions in Tokyo, including the conferences when Emperor Hirohito authorized the final decision to surrender. [1]

Ever since the atomic bombs were exploded over Japanese cities, historians, social scientists, journalists, World War II veterans, and ordinary citizens have engaged in intense controversy about the events of August 1945. John Hersey’s  Hiroshima , first published in the New Yorker  in 1946 encouraged unsettled readers to question the bombings while church groups and some commentators, most prominently Norman Cousins, explicitly criticized them. Former Secretary of War Henry Stimson found the criticisms troubling and published an influential justification for the attacks in  Harper’s . [2] During the 1960s the availability of primary sources made historical research and writing possible and the debate became more vigorous. Historians Herbert Feis and Gar Alperovitz raised searching questions about the first use of nuclear weapons and their broader political and diplomatic implications. The controversy, especially the arguments made by Alperovitz and others about “atomic diplomacy” quickly became caught up in heated debates over Cold War “revisionism.” The controversy simmered over the years with major contributions by Martin Sherwin and Barton J. Bernstein but it became explosive during the mid-1990s when curators at the National Air and Space Museum met the wrath of the Air Force Association over a proposed historical exhibit on the Enola Gay. [3] The NASM exhibit was drastically scaled-down but historians and journalist continued to engage in the debate. Alperovitz, Bernstein, and Sherwin made new contributions as did other historians, social scientists, and journalists including Richard B. Frank, Herbert Bix, Sadao Asada, Kai Bird, Robert James Maddox, Sean Malloy, Robert P. Newman, Robert S. Norris, Tsuyoshi Hagesawa, and J. Samuel Walker. [4]

The continued controversy has revolved around the following, among other, questions:

• were the atomic strikes necessary primarily to avert an invasion of Japan in November 1945?
• Did Truman authorize the use of atomic bombs for diplomatic-political reasons-- to intimidate the Soviets--or was his major goal to force Japan to surrender and bring the war to an early end?
• If ending the war quickly was the most important motivation of Truman and his advisers to what extent did they see an “atomic diplomacy” capability as a “bonus”?
• To what extent did subsequent justification for the atomic bomb exaggerate or misuse wartime estimates for U.S. casualties stemming from an invasion of Japan?
• Were there alternatives to the use of the weapons? If there were, what were they and how plausible are they in retrospect? Why were alternatives not pursued?
• How did the U.S. government plan to use the bombs? What concepts did war planners use to select targets? To what extent were senior officials interested in looking at alternatives to urban targets? How familiar was President Truman with the concepts that led target planners chose major cities as targets?
• What did senior officials know about the effects of atomic bombs before they were first used. How much did top officials know about the radiation effects of the weapons?
• Did President Truman make a decision, in a robust sense, to use the bomb or did he inherit a decision that had already been made?
• Were the Japanese ready to surrender before the bombs were dropped? To what extent had Emperor Hirohito prolonged the war unnecessarily by not seizing opportunities for surrender?
• If the United States had been more flexible about the demand for “unconditional surrender” by explicitly or implicitly guaranteeing a constitutional monarchy would Japan have surrendered earlier than it did?
• How decisive was the atomic bombings to the Japanese decision to surrender?
• Was the bombing of Nagasaki unnecessary? To the extent that the atomic bombing was critically important to the Japanese decision to surrender would it have been enough to destroy one city?
• Would the Soviet declaration of war have been enough to compel Tokyo to admit defeat?
• Was the dropping of the atomic bombs morally justifiable?

This compilation will not attempt to answer these questions or use primary sources to stake out positions on any of them. Nor is it an attempt to substitute for the extraordinary rich literature on the atomic bombings and the end of World War II. Nor does it include any of the interviews, documents prepared after the events, and post-World War II correspondence, etc. that participants in the debate have brought to bear in framing their arguments. Originally this collection did not include documents on the origins and development of the Manhattan Project, although this updated posting includes some significant records for context. By providing access to a broad range of U.S. and Japanese documents, mainly from the spring and summer of 1945, interested readers can see for themselves the crucial source material that scholars have used to shape narrative accounts of the historical developments and to frame their arguments about the questions that have provoked controversy over the years. To help readers who are less familiar with the debates, commentary on some of the documents will point out, although far from comprehensively, some of the ways in which they have been interpreted. With direct access to the documents, readers may develop their own answers to the questions raised above. The documents may even provoke new questions.

Contributors to the historical controversy have deployed the documents selected here to support their arguments about the first use of nuclear weapons and the end of World War II. The editor has closely reviewed the footnotes and endnotes in a variety of articles and books and selected documents cited by participants on the various sides of the controversy. [5] While the editor has a point of view on the issues, to the greatest extent possible he has tried to not let that influence document selection, e.g., by selectively withholding or including documents that may buttress one point of view or the other. The task of compilation involved consultation of primary sources at the National Archives, mainly in Manhattan Project files held in the records of the Army Corps of Engineers, Record Group 77, but also in the archival records of the National Security Agency. Private collections were also important, such as the Henry L. Stimson Papers held at Yale University (although available on microfilm, for example, at the Library of Congress) and the papers of W. Averell Harriman at the Library of Congress. To a great extent the documents selected for this compilation have been declassified for years, even decades; the most recent declassifications were in the 1990s.

The U.S. documents cited here will be familiar to many knowledgeable readers on the Hiroshima-Nagasaki controversy and the history of the Manhattan Project. To provide a fuller picture of the transition from U.S.-Japanese antagonism to reconciliation, the editor has done what could be done within time and resource constraints to present information on the activities and points of view of Japanese policymakers and diplomats. This includes a number of formerly top secret summaries of intercepted Japanese diplomatic communications, which enable interested readers to form their own judgments about the direction of Japanese diplomacy in the weeks before the atomic bombings. Moreover, to shed light on the considerations that induced Japan’s surrender, this briefing book includes new translations of Japanese primary sources on crucial events, including accounts of the conferences on August 9 and 14, where Emperor Hirohito made decisions to accept Allied terms of surrender.

[ Editor’s Note: Originally prepared in July 2005 this posting has been updated, with new documents, changes in organization, and other editorial changes. As noted, some documents relating to the origins of the Manhattan Project have been included in addition to entries from the Robert P. Meiklejohn diaries and translations of a few Soviet documents, among other items. Moreover, recent significant contributions to the scholarly literature have been taken into account.]

I. Background on the U.S. Atomic Project

Documents 1A-C: Report of the Uranium Committee

1A . Arthur H. Compton, National Academy of Sciences Committee on Atomic Fission, to Frank Jewett, President, National Academy of Sciences, 17 May 1941, Secret

1B . Report to the President of the National Academy of Sciences by the Academy Committee on Uranium, 6 November 1941, Secret

1C . Vannevar Bush, Director, Office of Scientific Research and Development, to President Roosevelt, 27 November 1941, Secret

Source: National Archives, Records of the Office of Scientific Research and Development, Record Group 227 (hereinafter RG 227), Bush-Conant papers microfilm collection, Roll 1, Target 2, Folder 1, "S-1 Historical File, Section A (1940-1941)."

This set of documents concerns the work of the Uranium Committee of the National Academy of Sciences, an exploratory project that was the lead-up to the actual production effort undertaken by the Manhattan Project. The initial report, May 1941, showed how leading American scientists grappled with the potential of nuclear energy for military purposes. At the outset, three possibilities were envisioned: radiological warfare, a power source for submarines and ships, and explosives. To produce material for any of those purposes required a capability to separate uranium isotopes in order to produce fissionable U-235. Also necessary for those capabilities was the production of a nuclear chain reaction. At the time of the first report, various methods for producing a chain reaction were envisioned and money was being budgeted to try them out.

Later that year, the Uranium Committee completed its report and OSRD Chairman Vannevar Bush reported the findings to President Roosevelt: As Bush emphasized, the U.S. findings were more conservative than those in the British MAUD report: the bomb would be somewhat “less effective,” would take longer to produce, and at a higher cost. One of the report’s key findings was that a fission bomb of superlatively destructive power will result from bringing quickly together a sufficient mass of element U235.” That was a certainty, “as sure as any untried prediction based upon theory and experiment can be.” The critically important task was to develop ways and means to separate highly enriched uranium from uranium-238. To get production going, Bush wanted to establish a “carefully chosen engineering group to study plans for possible production.” This was the basis of the Top Policy Group, or the S-1 Committee, which Bush and James B. Conant quickly established. [6]

In its discussion of the effects of an atomic weapon, the committee considered both blast and radiological damage. With respect to the latter, “It is possible that the destructive effects on life caused by the intense radioactivity of the products of the explosion may be as important as those of the explosion itself.” This insight was overlooked when top officials of the Manhattan Project considered the targeting of Japan during 1945. [7]

Documents 2A-B: Going Ahead with the Bomb

2A : Vannevar Bush to President Roosevelt, 9 March 1942, with memo from Roosevelt attached, 11 March 1942, Secret

2B : Vannevar Bush to President Roosevelt, 16 December 1942, Secret (report not attached)

Sources: 2A: RG 227, Bush-Conant papers microfilm collection, Roll 1, Target 2, Folder 1, "S-1 Historical File, Section II (1941-1942): 2B: Bush-Conant papers, S-1 Historical File, Reports to and Conferences with the President (1942-1944)

The Manhattan Project never had an official charter establishing it and defining its mission, but these two documents are the functional equivalent of a charter, in terms of presidential approvals for the mission, not to mention for a huge budget. In a progress report, Bush told President Roosevelt that the bomb project was on a pilot plant basis, but not yet at the production stage. By the summer, once “production plants” would be at work, he proposed that the War Department take over the project. In reply, Roosevelt wrote a short memo endorsing Bush’s ideas as long as absolute secrecy could be maintained. According to Robert S. Norris, this was “the fateful decision” to turn over the atomic project to military control. [8]

Some months later, with the Manhattan Project already underway and under the direction of General Leslie Grove, Bush outlined to Roosevelt the effort necessary to produce six fission bombs. With the goal of having enough fissile material by the first half of 1945 to produce the bombs, Bush was worried that the Germans might get there first. Thus, he wanted Roosevelt’s instructions as to whether the project should be “vigorously pushed throughout.” Unlike the pilot plant proposal described above, Bush described a real production order for the bomb, at an estimated cost of a “serious figure”: $400 million, which was an optimistic projection given the eventual cost of $1.9 billion. To keep the secret, Bush wanted to avoid a “ruinous” appropriations request to Congress and asked Roosevelt to ask Congress for the necessary discretionary funds. Initialed by President Roosevelt (“VB OK FDR”), this may have been the closest that he came to a formal approval of the Manhattan Project.

Document 3 : Memorandum by Leslie R. Grove, “Policy Meeting, 5/5/43,” Top Secret

Source:  National Archives, Record Group 77, Records of the Army Corps of Engineers (hereinafter RG 77), Manhattan Engineering District (MED), Minutes of the Military Policy Meeting (5 May 1943), Correspondence (“Top Secret”) of the Manhattan Engineer District, 1942-1946, microfilm publication M1109 (Washington, D.C.: National Archives and Records Administration, 1980), Roll 3, Target 6, Folder 23, “Military Policy Committee, Minutes of Meetings”

Before the Manhattan Project had produced any weapons, senior U.S. government officials had Japanese targets in mind. Besides discussing programmatic matters (e.g., status of gaseous diffusion plants, heavy water production for reactors, and staffing at Las Alamos), the participants agreed that the first use could be Japanese naval forces concentrated at Truk Harbor, an atoll in the Caroline Islands. If there was a misfire the weapon would be difficult for the Japanese to recover, which would not be the case if Tokyo was targeted. Targeting Germany was rejected because the Germans were considered more likely to “secure knowledge” from a defective weapon than the Japanese. That is, the United States could possibly be in danger if the Nazis acquired more knowledge about how to build a bomb. [9]

Document 4 :   Memo from General Groves to the Chief of Staff [Marshall], “Atomic Fission Bombs – Present Status and Expected Progress,” 7 August 1944, Top Secret, excised copy

Source: RG 77, Correspondence ("Top Secret") of the Manhattan Engineer District, 1942-1946, file 25M

This memorandum from General Groves to General Marshall captured how far the Manhattan Project had come in less than two years since Bush’s December 1942 report to President Roosevelt .  Groves did not mention this but around the time he wrote this the Manhattan Project had working at its far-flung installations over  125,000 people  ; taking into account high labor turnover some 485,000 people worked on the project (1 out of every 250 people in the country at that time). What these people were laboring to construct, directly or indirectly, were two types of weapons—a gun-type weapon using U-235 and an implosion weapon using plutonium (although the possibility of U-235 was also under consideration). As the scientists had learned, a gun-type weapon based on plutonium was “impossible” because that element had an “unexpected property”: spontaneous neutron emissions would cause the weapon to “fizzle.” [10]  For both the gun-type and the implosion weapons, a production schedule had been established and both would be available during 1945. The discussion of weapons effects centered on blast damage models; radiation and other effects were overlooked.

Document 5 : Memorandum from Vannevar Bush and James B. Conant, Office of Scientific Research and Development, to Secretary of War, September 30, 1944, Top Secret

Source: RG 77, Harrison-Bundy Files (H-B Files), folder 69 (copy from microfilm)

While Groves worried about the engineering and production problems, key War Department advisers were becoming troubled over the diplomatic and political implications of these enormously powerful weapons and the dangers of a global nuclear arms race. Concerned that President Roosevelt had an overly “cavalier” belief about the possibility of maintaining a post-war Anglo-American atomic monopoly, Bush and Conant recognized the limits of secrecy and wanted to disabuse senior officials of the notion that an atomic monopoly was possible. To suggest alternatives, they drafted this memorandum about the importance of the international exchange of information and international inspection to stem dangerous nuclear competition. [11]

Documents 6A-D: President Truman Learns the Secret:

6A : Memorandum for the Secretary of War from General L. R. Groves, “Atomic Fission Bombs,” April 23, 1945

6B : Memorandum discussed with the President, April 25, 1945

6C : [Untitled memorandum by General L.R. Groves, April 25, 1945

6D : Diary Entry, April 25, 1945

Sources: A: RG 77, Commanding General’s file no. 24, tab D; B: Henry Stimson Diary, Sterling Library, Yale University (microfilm at Library of Congress); C: Source: Record Group 200, Papers of General Leslie R. Groves, Correspondence 1941-1970, box 3, “F”; D: Henry Stimson Diary, Sterling Library, Yale University (microfilm at Library of Congress)

Soon after he was sworn in as president following President Roosevelt’s death, Harry Truman learned about the top secret Manhattan Project from a briefing from Secretary of War Stimson and Manhattan Project chief General Groves, who went through the “back door” to escape the watchful press. Stimson, who later wrote up the meeting in his diary, also prepared a discussion paper, which raised broader policy issues associated with the imminent possession of “the most terrible weapon ever known in human history.” In a background report prepared for the meeting, Groves provided a detailed overview of the bomb project from the raw materials to processing nuclear fuel to assembling the weapons to plans for using them, which were starting to crystallize.

With respect to the point about assembling the weapons, the first gun-type weapon “should be ready about 1 August 1945” while an implosion weapon would also be available that month. “The target is and was always expected to be Japan.” The question whether Truman “inherited assumptions” from the Roosevelt administration that that the bomb would be used has been a controversial one. Alperovitz and Sherwin have argued that Truman made “a real decision” to use the bomb on Japan by choosing “between various forms of diplomacy and warfare.” In contrast, Bernstein found that Truman “never questioned [the] assumption” that the bomb would and should be used. Norris also noted that “Truman’s `decision’ was a decision not to override previous plans to use the bomb.” [12]

II. Targeting Japan

Document 7 : Commander F. L. Ashworth to Major General L.R. Groves, “The Base of Operations of the 509 th  Composite Group,” February 24, 1945, Top Secret

Source: RG 77, MED Records, Top Secret Documents, File no. 5g

The force of B-29 nuclear delivery vehicles that was being readied for first nuclear use—the Army Air Force’s 509 th  Composite Group—required an operational base in the Western Pacific. In late February 1945, months before atomic bombs were ready for use, the high command selected Tinian, an island in the Northern Marianas Islands, for that base.

Document 8 : Headquarters XXI Bomber Command, “Tactical Mission Report, Mission No. 40 Flown 10 March 1945,”n.d., Secret

Source: Library of Congress, Curtis LeMay Papers, Box B-36

As part of the war with Japan, the Army Air Force waged a campaign to destroy major industrial centers with incendiary bombs. This document is General Curtis LeMay’s report on the firebombing of Tokyo--“the most destructive air raid in history”--which burned down over 16 square miles of the city, killed up to 100,000 civilians (the official figure was 83,793), injured more than 40,000, and made over 1 million homeless.  [13]  According to the “Foreword,” the purpose of the raid, which dropped 1,665 tons of incendiary bombs, was to destroy industrial and strategic targets “ not  to bomb indiscriminately civilian populations.” Air Force planners, however, did not distinguish civilian workers from the industrial and strategic structures that they were trying to destroy.

The killing of workers in the urban-industrial sector was one of the explicit goals of the air campaign against Japanese cities. According to a Joint Chiefs of Staff report on Japanese target systems, expected results from the bombing campaign included: “The absorption of man-hours in repair and relief; the dislocation of labor by casualty; the interruption of public services necessary to production, and above all the destruction of factories engaged in war industry.” While Stimson would later raise questions about the bombing of Japanese cities, he was largely disengaged from the details (as he was with atomic targeting). [14]

Firebombing raids on other cities followed Tokyo, including Osaka, Kobe, Yokahama, and Nagoya, but with fewer casualties (many civilians had fled the cities). For some historians, the urban fire-bombing strategy facilitated atomic targeting by creating a “new moral context,” in which earlier proscriptions against intentional targeting of civilians had eroded. [15]

Document 9 : Notes on Initial Meeting of Target Committee, May 2, 1945, Top Secret

Source: RG 77, MED Records, Top Secret Documents, File no. 5d (copy from microfilm)

On 27 April, military officers and nuclear scientists met to discuss bombing techniques, criteria for target selection, and overall mission requirements. The discussion of “available targets” included Hiroshima, the “largest untouched target not on the 21 st  Bomber Command priority list.” But other targets were under consideration, including Yawata (northern Kyushu), Yokohama, and Tokyo (even though it was practically “rubble.”) The problem was that the Air Force had a policy of “laying waste” to Japan’s cities which created tension with the objective of reserving some urban targets for nuclear destruction.  [16]

Document 10 : Memorandum from J. R. Oppenheimer to Brigadier General Farrell, May 11, 1945

Source: RG 77, MED Records, Top Secret Documents, File no. 5g (copy from microfilm)

As director of Los Alamos Laboratory, Oppenheimer’s priority was producing a deliverable bomb, but not so much the effects of the weapon on the people at the target. In keeping with General Groves’ emphasis on compartmentalization, the Manhattan Project experts on the effects of radiation on human biology were at the MetLab and other offices and had no interaction with the production and targeting units. In this short memorandum to Groves’ deputy, General Farrell, Oppenheimer explained the need for precautions because of the radiological dangers of a nuclear detonation. The initial radiation from the detonation would be fatal within a radius of about 6/10ths of a mile and “injurious” within a radius of a mile. The point was to keep the bombing mission crew safe; concern about radiation effects had no impact on targeting decisions.  [17]

Document 11 : Memorandum from Major J. A. Derry and Dr. N.F. Ramsey to General L.R. Groves, “Summary of Target Committee Meetings on 10 and 11 May 1945,” May 12, 1945, Top Secret

Scientists and officers held further discussion of bombing mission requirements, including height of detonation, weather, radiation effects (Oppenheimer’s memo), plans for possible mission abort, and the various aspects of target selection, including priority cities (“a large urban area of more than three miles diameter”) and psychological dimension. As for target cities, the committee agreed that the following should be exempt from Army Air Force bombing so they would be available for nuclear targeting: Kyoto, Hiroshima, Yokohama, and Kokura Arsenal. Japan’s cultural capital, Kyoto, would not stay on the list. Pressure from Secretary of War Stimson had already taken Kyoto off the list of targets for incendiary bombings and he would successfully object to the atomic bombing of that city.  [18]

Document 12 : Stimson Diary Entries, May 14 and 15, 1945

Source: Henry Stimson Diary, Sterling Library, Yale University (microfilm at Library of Congress)

On May 14 and 15, Stimson had several conversations involving S-1 (the atomic bomb); during a talk with Assistant Secretary of War John J. McCloy, he estimated that possession of the bomb gave Washington a tremendous advantage—“held all the cards,” a “royal straight flush”-- in dealing with Moscow on post-war problems: “They can’t get along without our help and industries and we have coming into action a weapon which will be unique.” The next day a discussion of divergences with Moscow over the Far East made Stimson wonder whether the atomic bomb would be ready when Truman met with Stalin in July. If it was, he believed that the bomb would be the “master card” in U.S. diplomacy. This and other entries from the Stimson diary (as well as the entry from the Davies diary that follows) are important to arguments developed by Gar Alperovitz and Barton J. Bernstein, among others, although with significantly different emphases, that in light of controversies with the Soviet Union over Eastern Europe and other areas, top officials in the Truman administration believed that possessing the atomic bomb would provide them with significant leverage for inducing Moscow’s acquiescence in U.S. objectives. [19]

Document 13 : Davies Diary entry for May 21, 1945

Source: Joseph E. Davies Papers, Library of Congress, box 17, 21 May 1945

While officials at the Pentagon continued to look closely at the problem of atomic targets, President Truman, like Stimson, was thinking about the diplomatic implications of the bomb. During a conversation with Joseph E. Davies, a prominent Washington lawyer and former ambassador to the Soviet Union, Truman said that he wanted to delay talks with Stalin and Churchill until July when the first atomic device had been tested. Alperovitz treated this entry as evidence in support of the atomic diplomacy argument, but other historians, ranging from Robert Maddox to Gabriel Kolko, have denied that the timing of the Potsdam conference had anything to do with the goal of using the bomb to intimidate the Soviets. [20]

Document 14 : Letter, O. C. Brewster to President Truman, 24 May 1945, with note from Stimson to Marshall, 30 May 1945, attached, secret

Source: Harrison-Bundy Files relating to the Development of the Atomic Bomb, 1942-1946, microfilm publication M1108 (Washington, D.C.: National Archives and Records Administration, 1980), File 77: "Interim Committee - International Control."

In what Stimson called the “letter of an honest man,” Oswald C. Brewster sent President Truman a profound analysis of the danger and unfeasibility of a U.S. atomic monopoly.  [21]  An engineer for the Kellex Corporation, which was involved in the gas diffusion project to enrich uranium, Brewster recognized that the objective was fissile material for a weapon. That goal, he feared, raised terrifying prospects with implications for the “inevitable destruction of our present day civilization.” Once the U.S. had used the bomb in combat other great powers would not tolerate a monopoly by any nation and the sole possessor would be “be the most hated and feared nation on earth.” Even the U.S.’s closest allies would want the bomb because “how could they know where our friendship might be five, ten, or twenty years hence.” Nuclear proliferation and arms races would be certain unless the U.S. worked toward international supervision and inspection of nuclear plants.

Brewster suggested that Japan could be used as a “target” for a “demonstration” of the bomb, which he did not further define. His implicit preference, however, was for non-use; he wrote that it would be better to take U.S. casualties in “conquering Japan” than “to bring upon the world the tragedy of unrestrained competitive production of this material.”

Document 15 : Minutes of Third Target Committee Meeting – Washington, May 28, 1945, Top Secret

More updates on training missions, target selection, and conditions required for successful detonation over the target. The target would be a city--either Hiroshima, Kyoto (still on the list), or Niigata--but specific “aiming points” would not be specified at that time nor would industrial “pin point” targets because they were likely to be on the “fringes” a city. The bomb would be dropped in the city’s center. “Pumpkins” referred to bright orange, pumpkin-shaped high explosive bombs—shaped like the “Fat Man” implosion weapon--used for bombing run test missions.

Document 16 : General Lauris Norstad to Commanding General, XXI Bomber Command, “509 th  Composite Group; Special Functions,” May 29, 1945, Top Secret

The 509 th  Composite Group’s cover story for its secret mission was the preparation of “Pumpkins” for use in battle. In this memorandum, Norstad reviewed the complex requirements for preparing B-29s and their crew for successful nuclear strikes.

Document 17 : Assistant Secretary of War John J. McCloy, “Memorandum of Conversation with General Marshal May 29, 1945 – 11:45 p.m.,” Top Secret

Source: Record Group 107, Office of the Secretary of War, Formerly Top Secret Correspondence of Secretary of War Stimson (“Safe File”), July 1940-September 1945, box 12, S-1

Tacitly dissenting from the Targeting Committee’s recommendations, Army Chief of Staff George Marshall argued for initial nuclear use against a clear-cut military target such as a “large naval installation.” If that did not work, manufacturing areas could be targeted, but only after warning their inhabitants. Marshall noted the “opprobrium which might follow from an ill considered employment of such force.” This document has played a role in arguments developed by Barton J. Bernstein that figures such as Marshall and Stimson were “caught between an older morality that opposed the intentional killing of non-combatants and a newer one that stressed virtually total war.” [22]  

Document 18 : “Notes of the Interim Committee Meeting Thursday, 31 May 1945, 10:00 A.M. to 1:15 P.M. – 2:15 P.M. to 4:15 P.M., ” n.d., Top Secret

Source: RG 77, MED Records, H-B files, folder no. 100 (copy from microfilm)

With Secretary of War Stimson presiding, members of the committee heard reports on a variety of Manhattan Project issues, including the stages of development of the atomic project, problems of secrecy, the possibility of informing the Soviet Union, cooperation with “like-minded” powers, the military impact of the bomb on Japan, and the problem of “undesirable scientists.” Interested in producing the “greatest psychological effect,” the Committee members agreed that the “most desirable target would be a vital war plant employing a large number of workers and closely surrounded by workers’ houses.” Exactly how the mass deaths of civilians would persuade Japanese rulers to surrender was not discussed. Bernstein has argued that this target choice represented an uneasy endorsement of “terror bombing”--the target was not exclusively military or civilian; nevertheless, worker’s housing would include non-combatant men, women, and children. [23]  It is possible that Truman was informed of such discussions and their conclusions, although he clung to a belief that the prospective targets were strictly military.

Document 19 : General George A. Lincoln to General Hull, June 4, 1945, enclosing draft, Top Secret

Source: Record Group 165, Records of the War Department General and Special Staffs, American-British-Canadian Top Secret Correspondence, Box 504, “ABC 387 Japan (15 Feb. 45)

George A. Lincoln, chief of the Strategy and Policy Group at U.S. Army’s Operations Department, commented on a memorandum by former President Herbert Hoover that Stimson had passed on for analysis. Hoover proposed a compromise solution with Japan that would allow Tokyo to retain part of its empire in East Asia (including Korea and Japan) as a way to head off Soviet influence in the region. While Lincoln believed that the proposed peace teams were militarily acceptable he doubted that they were workable or that they could check Soviet “expansion” which he saw as an inescapable result of World War II. As to how the war with Japan would end, he saw it as “unpredictable,” but speculated that “it will take Russian entry into the war, combined with a landing, or imminent threat of a landing, on Japan proper by us, to convince them of the hopelessness of their situation.” Lincoln derided Hoover’s casualty estimate of 500,000. J. Samuel Walker has cited this document to make the point that “contrary to revisionist assertions, American policymakers in the summer of 1945 were far from certain that the Soviet invasion of Manchuria would be enough in itself to force a Japanese surrender.”  [24]

Document 20 : Memorandum from R. Gordon Arneson, Interim Committee Secretary, to Mr. Harrison, June 6, 1945, Top Secret

In a memorandum to George Harrison, Stimson’s special assistant on Manhattan Project matters, Arneson noted actions taken at the recent Interim Committee meetings, including target criterion and an attack “without prior warning.”

Document 21 : Memorandum of Conference with the President, June 6, 1945, Top Secret

Source: Henry Stimson Papers, Sterling Library, Yale University (microfilm at Library of Congress)

Stimson and Truman began this meeting by discussing how they should handle a conflict with French President DeGaulle over the movement by French forces into Italian territory. (Truman finally cut off military aid to France to compel the French to pull back).  [25]  As evident from the discussion, Stimson strongly disliked de Gaulle whom he regarded as “psychopathic.” The conversation soon turned to the atomic bomb, with some discussion about plans to inform the Soviets but only after a successful test. Both agreed that the possibility of a nuclear “partnership” with Moscow would depend on “quid pro quos”: “the settlement of the Polish, Rumanian, Yugoslavian, and Manchurian problems.”

At the end, Stimson shared his doubts about targeting cities and killing civilians through area bombing because of its impact on the U.S.’s reputation as well as on the problem of finding targets for the atomic bomb. Barton Bernstein has also pointed to this as additional evidence of the influence on Stimson of an “an older morality.” While concerned about the U.S.’s reputation, Stimson did not want the Air Force to bomb Japanese cities so thoroughly that the “new weapon would not have a fair background to show its strength,” a comment that made Truman laugh.  The discussion of “area bombing” may have reminded him that Japanese civilians remained at risk from U.S. bombing operations.

III. Debates on Alternatives to First Use and Unconditional Surrender

Document 22 : Memorandum from Arthur B. Compton to the Secretary of War, enclosing “Memorandum on `Political and Social Problems,’ from Members of the `Metallurgical Laboratory’ of the University of Chicago,” June 12, 1945, Secret

Source: RG 77, MED Records, H-B files, folder no. 76 (copy from microfilm)

Physicists Leo Szilard and James Franck, a Nobel Prize winner, were on the staff of the “Metallurgical Laboratory” at the University of Chicago, a cover for the Manhattan Project program to produce fuel for the bomb. The outspoken Szilard was not involved in operational work on the bomb and General Groves kept him under surveillance but Met Lab director Arthur Compton found Szilard useful to have around. Concerned with the long-run implications of the bomb, Franck chaired a committee, in which Szilard and Eugene Rabinowitch were major contributors, that produced a report rejecting a surprise attack on Japan and recommended instead a demonstration of the bomb on the “desert or a barren island.” Arguing that a nuclear arms race “will be on in earnest not later than the morning after our first demonstration of the existence of nuclear weapons,” the committee saw international control as the alternative. That possibility would be difficult if the United States made first military use of the weapon. Compton raised doubts about the recommendations but urged Stimson to study the report. Martin Sherwin has argued that the Franck committee shared an important assumption with Truman et al.--that an “atomic attack against Japan would `shock’ the Russians”--but drew entirely different conclusions about the import of such a shock.  [26]

Document 23 : Memorandum from Acting Secretary of State Joseph Grew to the President, “Analysis of Memorandum Presented by Mr. Hoover,” June 13, 1945

Source: Record Group 107, Office of the Secretary of War, Formerly Top Secret Correspondence of Secretary of War Stimson (“Safe File”), July 1940-September 1945, box 8, Japan (After December 7/41)

A former ambassador to Japan, Joseph Grew’s extensive knowledge of Japanese politics and culture informed his stance toward the concept of unconditional surrender. He believed it essential that the United States declare its intention to preserve the institution of the emperor. As he argued in this memorandum to President Truman, “failure on our part to clarify our intentions” on the status of the emperor “will insure prolongation of the war and cost a large number of human lives.” Documents like this have played a role in arguments developed by Alperovitz that Truman and his advisers had alternatives to using the bomb such as modifying unconditional surrender and that anti-Soviet considerations weighed most heavily in their thinking. By contrast, Herbert P. Bix has suggested that the Japanese leadership would “probably not” have surrendered if the Truman administration had spelled out the status of the emperor. [27]

Document 24 : Memorandum from Chief of Staff Marshall to the Secretary of War, 15 June 1945, enclosing “Memorandum of Comments on `Ending the Japanese War,’” prepared by George A. Lincoln, June 14, 1945, Top Secret

Commenting on another memorandum by Herbert Hoover, George A. Lincoln discussed war aims, face-saving proposals for Japan, and the nature of the proposed declaration to the Japanese government, including the problem of defining “unconditional surrender.” Lincoln argued against modifying the concept of unconditional surrender: if it is “phrased so as to invite negotiation” he saw risks of prolonging the war or a “compromise peace.” J. Samuel Walker has observed that those risks help explain why senior officials were unwilling to modify the demand for unconditional surrender. [28]

Document 25 : Memorandum by J. R. Oppenheimer, “Recommendations on the Immediate Use of Nuclear Weapons,” June 16, 1945, Top Secret

In a report to Stimson, Oppenheimer and colleagues on the scientific advisory panel--Arthur Compton, Ernest O. Lawrence, and Enrico Fermi—tacitly disagreed with the report of the “Met Lab” scientists. The panel argued for early military use but not before informing key allies about the atomic project to open a dialogue on “how we can cooperate in making this development contribute to improved international relations.”

Document 26 : “Minutes of Meeting Held at the White House on Monday, 18 June 1945 at 1530,” Top Secret

Source: Record Group 218, Records of the Joint Chiefs of Staff, Central Decimal Files, 1942-1945, box 198 334 JCS (2-2-45) Mtg 186 th -194 th

With the devastating battle for Okinawa winding up, Truman and the Joint Chiefs stepped back and considered what it would take to secure Japan’s surrender. The discussion depicted a Japan that, by 1 November, would be close to defeat, with great destruction and economic losses produced by aerial bombing and naval blockade, but not ready to capitulate. Marshall believed that the latter required Soviet entry and an invasion of Kyushu, even suggesting that Soviet entry might be the “decisive action levering them into capitulation.” Truman and the Chiefs reviewed plans to land troops on Kyushu on 1 November, which Marshall believed was essential because air power was not decisive. He believed that casualties would not be more than those produced by the battle for Luzon, some 31,000. This account hints at discussion of the atomic bomb (“certain other matters”), but no documents disclose that part of the meeting.

The record of this meeting has figured in the complex debate over the estimates of casualties stemming from a possible invasion of Japan. While post-war justifications for the bomb suggested that an invasion of Japan could have produced very high levels of casualties (dead, wounded, or missing), from hundreds of thousands to a million, historians have vigorously debated the extent to which the estimates were inflated.  [29]

According to accounts based on post-war recollections and interviews, during the meeting McCloy raised the possibility of winding up the war by guaranteeing the preservation of the emperor albeit as a constitutional monarch. If that failed to persuade Tokyo, he proposed that the United States disclose the secret of the atomic bomb to secure Japan’s unconditional surrender. While McCloy later recalled that Truman expressed interest, he said that Secretary of State Byrnes squashed the proposal because of his opposition to any “deals” with Japan. Yet, according to Forrest Pogue’s account, when Truman asked McCloy if he had any comments, the latter opened up a discussion of nuclear weapons use by asking “Why not use the bomb?” [30]

Document 27 : Memorandum from R. Gordon Arneson, Interim Committee Secretary, to Mr. Harrison, June 25, 1945, Top Secret

For Harrison’s convenience, Arneson summarized key decisions made at the 21 June meeting of the Interim Committee, including a recommendation that President Truman use the forthcoming conference of allied leaders to inform Stalin about the atomic project. The Committee also reaffirmed earlier recommendations about the use of the bomb at the “earliest opportunity” against “dual targets.” In addition, Arneson included the Committee’s recommendation for revoking part two of the 1944 Quebec agreement which stipulated that the neither the United States nor Great Britain would use the bomb “against third parties without each other’s consent.” Thus, an impulse for unilateral control of nuclear use decisions predated the first use of the bomb.

Document 28 : Memorandum from George L. Harrison to Secretary of War, June 26, 1945, Top Secret

Source: RG 77, MED, H-B files, folder no. 77 (copy from microfilm)

Reminding Stimson about the objections of some Manhattan project scientists to military use of the bomb, Harrison summarized the basic arguments of the Franck report. One recommendation shared by many of the scientists, whether they supported the report or not, was that the United States inform Stalin of the bomb before it was used. This proposal had been the subject of positive discussion by the Interim Committee on the grounds that Soviet confidence was necessary to make possible post-war cooperation on atomic energy.

Document 29 : Memorandum from George L. Harrison to Secretary of War, June 28, 1945, Top Secret, enclosing Ralph Bard’s “Memorandum on the Use of S-1 Bomb,” June 27, 1945

Under Secretary of the Navy Ralph Bard joined those scientists who sought to avoid military use of the bomb; he proposed a “preliminary warning” so that the United States would retain its position as a “great humanitarian nation.” Alperovitz cites evidence that Bard discussed his proposal with Truman who told him that he had already thoroughly examined the problem of advanced warning. This document has also figured in the argument framed by Barton Bernstein that Truman and his advisers took it for granted that the bomb was a legitimate weapon and that there was no reason to explore alternatives to military use. Bernstein, however, notes that Bard later denied that he had a meeting with Truman and that White House appointment logs support that claim. [31]

Document 30 : Memorandum for Mr. McCloy, “Comments re: Proposed Program for Japan,” June 28, 1945, Draft, Top Secret

Source: RG 107, Office of Assistant Secretary of War Formerly Classified Correspondence of John J. McCloy, 1941-1945, box 38, ASW 387 Japan

Despite the interest of some senior officials such as Joseph Grew, Henry Stimson, and John J. McCloy in modifying the concept of unconditional surrender so that the Japanese could be sure that the emperor would be preserved, it remained a highly contentious subject. For example, one of McCloy’s aides, Colonel Fahey, argued against modification of unconditional surrender (see “Appendix ‘C`”).

Document 31 : Assistant Secretary of War John J. McCloy to Colonel Stimson, June 29, 1945, Top Secret

McCloy was part of a drafting committee at work on the text of a proclamation to Japan to be signed by heads of state at the forthcoming Potsdam conference. As McCloy observed the most contentious issue was whether the proclamation should include language about the preservation of the emperor: “This may cause repercussions at home but without it those who seem to know the most about Japan feel there would be very little likelihood of acceptance.”

Document 32 : Memorandum, “Timing of Proposed Demand for Japanese Surrender,” June 29, 1945, Top Secret

Probably the work of General George A. Lincoln at Army Operations, this document was prepared a few weeks before the Potsdam conference when senior officials were starting to finalize the text of the declaration that Truman, Churchill, and Chiang would issue there. The author recommended issuing the declaration “just before the bombardment program [against Japan] reaches its peak.” Next to that suggestion, Stimson or someone in his immediate office, wrote “S1”, implying that the atomic bombing of Japanese cities was highly relevant to the timing issue. Also relevant to Japanese thinking about surrender, the author speculated, was the Soviet attack on their forces after a declaration of war.

Document 33 : Stimson memorandum to The President, “Proposed Program for Japan,” 2 July 1945, Top Secret

Source: Naval Aide to the President Files, box 4, Berlin Conference File, Volume XI - Miscellaneous papers: Japan, Harry S. Truman Presidential Library

On 2 July Stimson presented to President Truman a proposal that he had worked up with colleagues in the War Department, including McCloy, Marshall, and Grew. The proposal has been characterized as “the most comprehensive attempt by any American policymaker to leverage diplomacy” in order to shorten the Pacific War. Stimson had in mind a “carefully timed warning” delivered before the invasion of Japan. Some of the key elements of Stimson’s argument were his assumption that “Japan is susceptible to reason” and that Japanese might be even more inclined to surrender if “we do not exclude a constitutional monarchy under her present dynasty.” The possibility of a Soviet attack would be part of the “threat.” As part of the threat message, Stimson alluded to the “inevitability and completeness of the destruction” which Japan could suffer, but he did not make it clear whether unconditional surrender terms should be clarified before using the atomic bomb. Truman read Stimson’s proposal, which he said was “powerful,” but made no commitments to the details, e.g., the position of the emperor.  [32]

Document 34 : Minutes, Secretary’s Staff Committee, Saturday Morning, July 7, 1945, 133d Meeting, Top Secret

Source: Record Group 353, Records of Interdepartmental and Intradepartmental Committees, Secretary’s Staff Meetings Minutes, 1944-1947 (copy from microfilm)

The possibility of modifying the concept of unconditional surrender so that it guaranteed the continuation of the emperor remained hotly contested within the U.S. government. Here senior State Department officials, Under Secretary Joseph Grew on one side, and Assistant Secretary Dean Acheson and Archibald MacLeish on the other, engaged in hot debate.

Document 35 : Combined Chiefs of Staff, “Estimate of the Enemy Situation (as of 6 July 1945, C.C.S 643/3, July 8, 1945, Secret (Appendices Not Included)

Source: RG 218, Central Decimal Files, 1943-1945, CCS 381 (6-4-45), Sec. 2 Pt. 5

This review of Japanese capabilities and intentions portrays an economy and society under “tremendous strain”; nevertheless, “the ground component of the Japanese armed forces remains Japan’s greatest military asset.” Alperovitz sees statements in this estimate about the impact of Soviet entry into the war and the possibility of a conditional surrender involving survival of the emperor as an institution as more evidence that the policymakers saw alternatives to nuclear weapons use. By contrast, Richard Frank takes note of the estimate’s depiction of the Japanese army’s terms for peace: “for surrender to be acceptable to the Japanese army it would be necessary for the military leaders to believe that it would not entail discrediting the warrior tradition and that it would permit the ultimate resurgence of a military in Japan.” That, Frank argues, would have been “unacceptable to any Allied policy maker.” [33]

Document 36 : Cable to Secretary of State from Acting Secretary Joseph Grew, July 16, 1945, Top Secret

Source: Record Group 59, Decimal Files 1945-1949, 740.0011 PW (PE)/7-1645

On the eve of the Potsdam Conference, a State Department draft of the proclamation to Japan contained language which modified unconditional surrender by promising to retain the emperor. When former Secretary of State Cordell Hull learned about it he outlined his objections to Byrnes, arguing that it might be better to wait “the climax of allied bombing and Russia’s entry into the war.” Byrnes was already inclined to reject that part of the draft, but Hull’s argument may have reinforced his decision.

Document 37 : Letter from Stimson to Byrnes, enclosing memorandum to the President, “The Conduct of the War with Japan,” 16 July 1945, Top Secret

Source: Henry L. Stimson Papers (MS 465), Sterling Library, Yale University (reel 113) (microfilm at Library of Congress)

Still interested in trying to find ways to “warn Japan into surrender,” this represents an attempt by Stimson before the Potsdam conference, to persuade Truman and Byrnes to agree to issue warnings to Japan prior to the use of the bomb. The warning would draw on the draft State-War proclamation to Japan; presumably, the one criticized by Hull (above) which included language about the emperor .  Presumably the clarified warning would be issued prior to the use of the bomb; if the Japanese persisted in fighting then “the full force of our new weapons should be brought to bear” and a “heavier” warning would be issued backed by the “actual entrance of the Russians in the war.” Possibly, as Malloy has argued, Stimson was motivated by concerns about using the bomb against civilians and cities, but his latest proposal would meet resistance at Potsdam from Byrnes and other. [34]

Document 38 : R. E. Lapp, Leo Szilard et al., “A Petition to the President of the United States,” July 17, 1945

On the eve of the Potsdam conference, Leo Szilard circulated a petition as part of a final effort to discourage military use of the bomb. Signed by about 68 Manhattan Project scientists, mainly physicists and biologists (copies with the remaining signatures are in the archival file), the petition did not explicitly reject military use, but raised questions about an arms race that military use could instigate and requested Truman to publicize detailed terms for Japanese surrender. Truman, already on his way to Europe, never saw the petition. [35]

IV. The Japanese Search for Soviet Mediation

Documents 39A-B: Magic

39A : William F. Friedman, Consultant (Armed Forces Security Agency), “A Short History of U.S. COMINT Activities,” 19 February 1952, Top Secret

39B :“Magic” – Diplomatic Summary, War Department, Office of Assistant Chief of Staff, G-2, No. 1204 – July 12, 1945, Top Secret Ultra

Sources: A: National Security Agency Mandatory declassification review release; B: Record Group 457, Records of the National Security Agency/Central Security Service, “Magic” Diplomatic Summaries 1942-1945, box 18

Beginning in September 1940, U.S. military intelligence began to decrypt routinely, under the “Purple” code-name, the intercepted cable traffic of the Japanese Foreign Ministry. Collectively the decoded messages were known as “Magic.” How this came about is explained in an internal history of pre-war and World War II Army and Navy code-breaking activities prepared by  William F. Friedman , a central figure in the development of U.S. government cryptology during the 20 th  century. The National Security Agency kept the ‘Magic” diplomatic and military summaries classified for many years and did not release the entire series for 1942 through August 1945 until the early 1990s. [36]

The 12 July 1945 “Magic” summary includes a report on a cable from Japanese Foreign Minister Shigenori Togo to Ambassador Naotake Sato in Moscow concerning the Emperor’s decision to seek Soviet help in ending the war. Not knowing that the Soviets had already made a commitment to their Allies to declare war on Japan, Tokyo fruitlessly pursued this option for several weeks. The “Magic” intercepts from mid-July have figured in Gar Alperovitz’s argument that Truman and his advisers recognized that the Emperor was ready to capitulate if the Allies showed more flexibility on the demand for unconditional surrender. This point is central to Alperovitz’s thesis that top U.S. officials recognized a “two-step logic”: relaxing unconditional surrender and a Soviet declaration of war would have been enough to induce Japan’s surrender without the use of the bomb. [37]

Document 40 : John Weckerling, Deputy Assistant Chief of Staff, G-2, July 12, 1945, to Deputy Chief of Staff, “Japanese Peace Offer,” 13 July 1945, Top Secret Ultra

Source: RG 165, Army Operations OPD Executive File #17, Item 13 (copy courtesy of J. Samuel Walker)

The day after the Togo message was reported, Army intelligence chief Weckerling proposed several possible explanations of the Japanese diplomatic initiative. Robert J. Maddox has cited this document to support his argument that top U.S. officials recognized that Japan was not close to surrender because Japan was trying to “stave off defeat.” In a close analysis of this document, Tsuyoshi Hasegawa, who is also skeptical of claims that the Japanese had decided to surrender, argues that each of the three possibilities proposed by Weckerling “contained an element of truth, but none was entirely correct”. For example, the “governing clique” that supported the peace moves was not trying to “stave off defeat” but was seeking Soviet help to end the war. [38]

Document 41 : “Magic” – Diplomatic Summary, War Department, Office of Assistant Chief of Staff, G-2, No. 1205 – July 13, 1945, Top Secret Ultra

Source: Record Group 457, Records of the National Security Agency/Central Security Service, “Magic” Diplomatic Summaries 1942-1945, box 18

The day after he told Sato about the current thinking on Soviet mediation, Togo requested the Ambassador to see Soviet Foreign Minister Vyacheslav Molotov and tell him of the Emperor’s “private intention to send Prince Konoye as a Special Envoy” to Moscow. Before he received Togo’s message, Sato had already met with Molotov on another matter.

Document 42 : “Magic” – Diplomatic Summary, War Department, Office of Assistant Chief of Staff, G-2, No. 1210 – July 17, 1945, Top Secret Ultra

Source: Record Group 457, Records of the National Security Agency/Central Security Service, “Magic” Diplomatic Summaries 1942-1945, box 18.

Another intercept of a cable from Togo to Sato shows that the Foreign Minister rejected unconditional surrender and that the Emperor was not “asking the Russian’s mediation in anything like unconditional surrender.” Incidentally, this “`Magic’ Diplomatic Summary” indicates the broad scope and capabilities of the program; for example, it includes translations of intercepted French messages (see pages 8-9).

Document 43 : Admiral Tagaki Diary Entry for July 20, 1945

Source: Takashi Itoh, ed.,  Sokichi Takagi: Nikki to Joho  [Sokichi Takagi: Diary and Documents] (Tokyo, Japan: Misuzu-Shobo, 2000), 916-917 [Translation by Hikaru Tajima]

In 1944 Navy minister Mitsumasa Yonai ordered rear admiral Sokichi Takagi to go on sick leave so that he could undertake a secret mission to find a way to end the war. Tagaki was soon at the center of a cabal of Japanese defense officials, civil servants, and academics, which concluded that, in the end, the emperor would have to “impose his decision on the military and the government.” Takagi kept a detailed account of his activities, part of which was in diary form, the other part of which he kept on index cards. The material reproduced here gives a sense of the state of play of Foreign Minister Togo’s attempt to secure Soviet mediation. Hasegawa cited it and other documents to make a larger point about the inability of the Japanese government to agree on “concrete” proposals to negotiate an end to the war. [39]

The last item discusses Japanese contacts with representatives of the Office of Strategic Services (OSS) in Switzerland. The reference to “our contact” may refer to Bank of International Settlements economist Pers Jacobbson who was in touch with Japanese representatives to the Bank as well as Gero von Gävernitz, then on the staff, but with non-official cover, of OSS station chief Allen Dulles. The contacts never went far and Dulles never received encouragement to pursue them. [40]

V. The Trinity Test

Document 44 : Letter from Commissar of State Security First Rank, V. Merkulov, to People’s Commissar for Internal Affairs L. P. Beria, 10 July 1945, Number 4305/m, Top Secret (translation by Anna Melyaskova)

Source:  L.D. Riabev, ed.,  Atomnyi Proekt SSSR  (Moscow: izd MFTI, 2002), Volume 1, Part 2, 335-336

This 10 July 1945 letter from NKVD director V. N. Merkulov to Beria is an example of Soviet efforts to collect inside information on the Manhattan Project, although not all the detail was accurate. Merkulov reported that the United States had scheduled the test of a nuclear device for that same day, although the actual test took place 6 days later. According to Merkulov, two fissile materials were being produced: element-49 (plutonium), and U-235; the test device was fueled by plutonium. The Soviet source reported that the weight of the device was 3 tons (which was in the ball park) and forecast an explosive yield of 5 kilotons. That figure was based on underestimates by Manhattan Project scientists: the actual yield of the test device was 20 kilotons.

As indicated by the L.D. Riabev’s notes, it is possible that Beria’s copy of this letter ended up in Stalin’s papers. That the original copy is missing from Beria’s papers suggests that he may have passed it on to Stalin before the latter left for the Potsdam conference. [41]

Document 45 : Telegram War [Department] 33556, from Harrison to Secretary of War, July 17, 1945, Top Secret

Source: RG 77, MED Records, Top Secret Documents, File 5e (copy from microfilm)

An elated message from Harrison to Stimson reported the success of the  Trinity Test  of a plutonium implosion weapon. The light from the explosion could been seen “from here [Washington, D.C.] to “high hold” [Stimson’s estate on Long Island—250 miles away]” and it was so loud that Harrison could have heard the “screams” from Washington, D.C. to “my farm” [in Upperville, VA, 50 miles away] [42]

Document 46 : Memorandum from General L. R. Groves to Secretary of War, “The Test,” July 18, 1945, Top Secret, Excised Copy

Source: RG 77, MED Records, Top Secret Documents, File no. 4 (copy from microfilm)

General Groves prepared for Stimson, then at Potsdam, a detailed account of the Trinity test. [43]

VI. The Potsdam Conference

Document 47 : Truman’s Potsdam Diary

Source: Barton J. Bernstein, “Truman at Potsdam: His Secret Diary,”  Foreign Service Journal , July/August 1980, excerpts, used with author’s permission. [44]

Some years after Truman’s death, a hand-written diary that he kept during the Potsdam conference surfaced in his personal papers. For convenience, Barton Bernstein’s rendition is provided here but linked here are the scanned versions of Truman’s handwriting on the National Archives’ website (for 15-30 July).

The diary entries cover July 16, 17, 18, 20, 25, 26, and 30 and include Truman’s thinking about a number of issues and developments, including his reactions to Churchill and Stalin, the atomic bomb and how it should be targeted, the possible impact of the bomb and a Soviet declaration of war on Japan, and his decision to tell Stalin about the bomb. Receptive to pressure from Stimson, Truman recorded his decision to take Japan’s “old capital” (Kyoto) off the atomic bomb target list. Barton Bernstein and Richard Frank, among others, have argued that Truman’s assertion that the atomic targets were “military objectives” suggested that either he did not understand the power of the new weapons or had simply deceived himself about the nature of the targets. Another statement—“Fini Japs when that [Soviet entry] comes about”—has also been the subject of controversy over whether it meant that Truman thought it possible that the war could end without an invasion of Japan. [45]

Document 48 : Stimson Diary entries for July 16 through 25, 1945

Stimson did not always have Truman’s ear, but historians have frequently cited his diary when he was at the Potsdam conference. There Stimson kept track of S-1 developments, including news of the successful first test (see entry for July 16) and the ongoing deployments for nuclear use against Japan. When Truman received a detailed account of the test, Stimson reported that the “President was tremendously pepped up by it” and that “it gave him an entirely new feeling of confidence” (see entry for July 21). Whether this meant that Truman was getting ready for a confrontation with Stalin over Eastern Europe and other matters has also been the subject of debate.

An important question that Stimson discussed with Marshall, at Truman’s request, was whether Soviet entry into the war remained necessary to secure Tokyo’s surrender. Marshall was not sure whether that was so although Stimson privately believed that the atomic bomb would provide enough to force surrender (see entry for July 23). This entry has been cited by all sides of the controversy over whether Truman was trying to keep the Soviets out of the war. [46]  During the meeting on August 24, discussed above, Stimson gave his reasons for taking Kyoto off the atomic target list: destroying that city would have caused such “bitterness” that it could have become impossible “to reconcile the Japanese to us in that area rather than to the Russians.” Stimson vainly tried to preserve language in the Potsdam Declaration designed to assure the Japanese about “the continuance of their dynasty” but received Truman’s assurance that such a consideration could be conveyed later through diplomatic channels (see entry for July 24). Hasegawa argues that Truman realized that the Japanese would refuse a demand for unconditional surrender without a proviso on a constitutional monarchy and that “he needed Japan’s refusal to justify the use of the atomic bomb.” [47]

Document 49 : Walter Brown Diaries, July 10-August 3, 1945

Source: Clemson University Libraries, Special Collections, Clemson, SC; Mss 243, Walter J. Brown Papers, box 10, folder 12, Byrnes, James F.: Potsdam, Minutes, July-August 1945

Walter Brown, who served as special assistant to Secretary of State Byrnes, kept a diary which provided considerable detail on the Potsdam conference and the growing concerns about Soviet policy among top U.S. officials. This document is a typed-up version of the hand-written original (which Brown’s family has provided to Clemson University). That there may be a difference between the two sources becomes evident from some of the entries; for example, in the entry for July 18, 1945 Brown wrote: "Although I knew about the atomic bomb when I wrote these notes, I dared not place it in writing in my book.”

The degree to which the typed-up version reflects the original is worth investigating. In any event, historians have used information from the diary to support various interpretations. For example, Bernstein cites the entries for 20 and 24 July to argue that “American leaders did not view Soviet entry as a substitute for the bomb” but that the latter “would be so powerful, and the Soviet presence in Manchuria so militarily significant, that there was no need for actual Soviet intervention in the war.” For  Brown's diary entry of 3 August 9 1945 historians have developed conflicting interpretations (See discussion of document 57). [48]

Document 50 : “Magic” – Diplomatic Summary, War Department, Office of Assistant Chief of Staff, G-2, No. 1214 – July 22, 1945, Top Secret Ultra

This “Magic” summary includes messages from both Togo and Sato. In a long and impassioned message, the latter argued why Japan must accept defeat: “it is meaningless to prove one’s devotion [to the Emperor] by wrecking the State.” Togo rejected Sato’s advice that Japan could accept unconditional surrender with one qualification: the “preservation of the Imperial House.” Probably unable or unwilling to take a soft position in an official cable, Togo declared that “the whole country … will pit itself against the enemy in accordance with the Imperial Will as long as the enemy demands unconditional surrender.”

Document 51 : Forrestal Diary Entry, July 24, 1945, “Japanese Peace Feelers”

Source: Naval Historical Center, Operational Archives, James Forrestal Diaries

Secretary of the Navy James Forrestal was a regular recipient of “Magic” intercept reports; this substantial entry reviews the dramatic Sato-Togo exchanges covered in the 22 July “Magic” summary (although Forrestal misdated Sato’s cable as “first of July” instead of the 21 st ). In contrast to Alperovitz’s argument that Forrestal tried to modify the terms of unconditional surrender to give the Japanese an out, Frank sees Forrestal’s account of the Sato-Togo exchange as additional evidence that senior U.S. officials understood that Tokyo was not on the “cusp of surrender.”  [49]

Document 52 : Davies Diary entry for July 29, 1945

S ource: Joseph E. Davies Papers, Library of Congress, Manuscripts Division, box 19, 29 July 1945

Having been asked by Truman to join the delegation to the Potsdam conference, former-Ambassador Davies sat at the table with the Big Three throughout the discussions. This diary entry has figured in the argument that Byrnes believed that the atomic bomb gave the United States a significant advantage in negotiations with the Soviet Union. Plainly Davies thought otherwise. [50]

VII. Debates among the Japanese – Late July/Early August 1945

Document 53 : “Magic” – Diplomatic Summary, War Department, Office of Assistant Chief of Staff, G-2, No. 1221- July 29, 1945, Top Secret Ultra

In the  Potsdam Declaration  the governments of China, Great Britain, and the United States) demanded the “unconditional surrender of all Japanese armed forces. “The alternative is prompt and utter destruction.” The next day, in response to questions from journalists about the government’s reaction to the ultimatum, Prime Minister Suzuki apparently said that “We can only ignore [ mokusatsu ] it. We will do our utmost to complete the war to the bitter end.” That, Bix argues, represents a “missed opportunity” to end the war and spare the Japanese from continued U.S. aerial attacks. [51]  Togo’s private position was more nuanced than Suzuki’s; he told Sato that “we are adopting a policy of careful study.” That Stalin had not signed the declaration (Truman and Churchill did not ask him to) led to questions about the Soviet attitude. Togo asked Sato to try to meet with Soviet Foreign Minister Molotov as soon as possible to “sound out the Russian attitude” on the declaration as well as Japan’s end-the-war initiative. Sato cabled Togo earlier that he saw no point in approaching the Soviets on ending the war until Tokyo had “concrete proposals.” “Any aid from the Soviets has now become extremely doubtful.”

Document 54 : “Magic” – Diplomatic Summary, War Department, Office of Assistant Chief of Staff, G-2, No. 1222 – July 30, 1945, Top Secret Ultra

This report included an intercept of a message from Sato reporting that it was impossible to see Molotov and that unless the Togo had a “concrete and definite plan for terminating the war” he saw no point in attempting to meet with him.

Document 55 : “Magic” – Diplomatic Summary, War Department, Office of Assistant Chief of Staff, G-2, No. 1225 – August 2, 1945, Top Secret Ultra

An intercepted message from Togo to Sato showed that Tokyo remained interested in securing Moscow’s good office but that it “is difficult to decide on concrete peace conditions here at home all at once.” “[W]e are exerting ourselves to collect the views of all quarters on the matter of concrete terms.” Barton Bernstein, Richard Frank, and Tsuyoshi Hasegawa, among others, have argued that the “Magic” intercepts from the end of July and early August show that the Japanese were far from ready to surrender. According to Herbert Bix, for months Hirohito had believed that the “outlook for a negotiated peace could be improved if Japan fought and won one last decisive battle,” thus, he delayed surrender, continuing to “procrastinate until the bomb was dropped and the Soviets attacked.” [52]

Document 56 : “Magic” – Diplomatic Summary, War Department, Office of Assistant Chief of Staff, G-2, No. 1226 - August 3, 1945, Top Secret Ultra

This summary included intercepts of Japanese diplomatic reporting on the Soviet buildup in the Far East as well as a naval intelligence report on Anglo-American discussions of U.S. plans for the invasion of Japan. Part II of the summary includes the rest of Togo’s 2 August cable which instructed Sato to do what he could to arrange an interview with Molotov.

Document 57 : Walter Brown Meeting Notes, August 3, 1945

Historians have used this item in the papers of Byrne’s aide, Walter Brown, to make a variety of points. Richard Frank sees this brief discussion of Japan’s interest in Soviet diplomatic assistance as crucial evidence that Admiral Leahy had been sharing “MAGIC” information with President Truman. He also points out that Truman and his colleagues had no idea what was behind Japanese peace moves, only that Suzuki had declared that he would “ignore” the Potsdam Declaration. Alperovitz, however, treats it as additional evidence that “strongly suggests” that Truman saw alternatives to using the bomb. [53]

Document 58 : “Magic” – Far East Summary, War Department, Office of Assistant Chief of Staff, G-2, no. 502, 4 August 1945

Source: RG 457, Summaries of Intercepted Japanese Messages (“Magic” Far East Summary, March 20, 1942 – October 2, 1945), box 7, SRS 491-547

This “Far East Summary” included reports on the Japanese Army’s plans to disperse fuel stocks to reduce vulnerability to bombing attacks, the text of a directive by the commander of naval forces on “Operation Homeland,” the preparations and planning to repel a U.S. invasion of Honshu, and the specific identification of army divisions located in, or moving into, Kyushu. Both Richard Frank and Barton Bernstein have used intelligence reporting and analysis of the major buildup of Japanese forces on southern Kyushu to argue that U.S. military planners were so concerned about this development that by early August 1945 they were reconsidering their invasion plans. [54]

Document 59 : “Magic” – Diplomatic Summary, War Department, Office of Assistant Chief of Staff, G-2, No. 1228 – August 5, 1945, Top Secret Ultra

This summary included several intercepted messages from Sato, who conveyed his despair and exasperation over what he saw as Tokyo’s inability to develop terms for ending the war: “[I]f the Government and the Military dilly-dally in bringing this resolution to fruition, then all Japan will be reduced to ashes.” Sato remained skeptical that the Soviets would have any interest in discussions with Tokyo: “it is absolutely unthinkable that Russia would ignore the Three Power Proclamation and then engage in conversations with our special envoy.”

VIII. The Execution Order

Documents 60a-d: Framing the Directive for Nuclear Strikes:

60A . Cable VICTORY 213 from Marshall to Handy, July 22, 1945, Top Secret

60B . Memorandum from Colonel John Stone to General Arnold, “Groves Project,” 24 July 1945, Top Secret

60C . Cable WAR 37683 from General Handy to General Marshal, enclosing directive to General Spatz, July 24, 1945, Top Secret

60D . Cable VICTORY 261 from Marshall to General Handy, July 25, 1945, 25 July 1945, Top Secret

60E . General Thomas T. Handy to General Carl Spaatz, July 26, 1945, Top Secret

Source: RG 77, MED Records, Top Secret Documents, Files no. 5b and 5e ((copies from microfilm)

Top Army Air Force commanders may not have wanted to take responsibility for the first use of nuclear weapons on urban targets and sought formal authorization from Chief of Staff Marshall who was then in Potsdam. [55]  On 22 July Marshall asked Deputy Chief of Staff Thomas Handy to prepare a draft; General Groves wrote one which went to Potsdam for Marshall’s approval. Colonel John Stone, an assistant to commanding General of the Army Air Forces Henry H. “Hap” Arnold, had just returned from Potsdam and updated his boss on the plans as they had developed. On 25 July Marshall informed Handy that Secretary of War Stimson had approved the text; that same day, Handy signed off on a directive which ordered the use of atomic weapons on Japan, with the first weapon assigned to one of four possible targets—Hiroshima, Kokura, Niigata, or Nagasaki. “Additional bombs will be delivery on the [targets] as soon as made ready by the project staff.”

Document 61 : Memorandum from Major General L. R. Groves to Chief of Staff, July 30, 1945, Top Secret, Sanitized Copy

Source: RG 77, MED Records, Top Secret Documents, File no. 5

With more information on the Alamogordo test available, Groves provided Marshall with detail on the destructive power of atomic weapons. Barton J. Bernstein has observed that Groves’ recommendation that troops could move into the “immediate explosion area” within a half hour demonstrates the prevalent lack of top-level knowledge of the dangers of nuclear weapons effects. [56]  Groves also provided the schedule for the delivery of the weapons: the components of the gun-type bomb to be used on Hiroshima had arrived on Tinian, while the parts of the second weapon to be dropped were leaving San Francisco. By the end of November over ten weapons would be available, presumably in the event the war had continued.

Documents 62A-C: Weather delays

62A . CG 313 th  Bomb Wing, Tinian cable APCOM 5112 to War Department, August 3, 1945, Top Secret

62B . CG 313 th  Bomb Wing, Tinian cable APCOM 5130 to War Department, August 4, 1945, Top Secret

62C . CG 313 th  Bomb Wing, Tinian cable APCOM 5155 to War Department, August 4, 1945, Top Secret

Source: RG 77, Tinian Files, April-December 1945, box 21 (copies courtesy of Barton Bernstein)

The Hiroshima “operation” was originally slated to begin in early August depending on local conditions. As these cables indicate, reports of unfavorable weather delayed the plan. The second cable on 4 August shows that the schedule advanced to late in the evening of 5 August. The handwritten transcriptions are on the original archival copies.

IX. The First Nuclear Strikes and their Impact

Document 63 : Memorandum from General L. R. Groves to the Chief of Staff, August 6, 1945, Top Secret

Source: RG 77, MED Records, Top Secret Documents, File no. 5b (copy from microfilm)

Two days after the bombing of Hiroshima, Groves provided Chief of Staff Marshall with a report which included messages from Captain William S. Parsons and others about the impact of the detonation which, through prompt radiation effects, fire storms, and blast effects, immediately killed at least 70,000, with many dying later from radiation sickness and other causes. [57]

How influential the atomic bombings of Hiroshima and later Nagasaki compared to the impact of the Soviet declaration of war were to the Japanese decision to surrender has been the subject of controversy among historians. Sadao Asada emphasizes the shock of the atomic bombs, while Herbert Bix has suggested that Hiroshima and the Soviet declaration of war made Hirohito and his court believe that failure to end the war could lead to the destruction of the imperial house. Frank and Hasegawa divide over the impact of the Soviet declaration of war, with Frank declaring that the Soviet intervention was “significant but not decisive” and Hasegawa arguing that the two atomic bombs “were not sufficient to change the direction of Japanese diplomacy. The Soviet invasion was.” [58]

Document 64 : Walter Brown Diary Entry, 6 August 1945

Source:  Clemson University Libraries, Special Collections, Clemson, SC; Mss 243, Walter J. Brown Papers, box 68, folder 13, “Transcript/Draft B

Returning from the Potsdam Conference, sailing on the  U.S.S. Augusta , Truman learned about the atomic bombing of Hiroshima and announced it twice, first to those in the wardroom (socializing/dining area for commissioned officers), and then to the sailors’ mess. Still unaware of radiation effects, Truman emphasized the explosive yield. Later, he met with Secretary of State Byrnes and they discussed the Manhattan Project’s secrecy and the huge expenditures. Truman, who had been chair of the Senate Special Committee to Investigate the National Defense Program, said that “only on the appeal of Secretary of War Stimson did he refrain and let the War Department continue with the experiment unmolested.”

Document 65 : Directive from the Supreme Command Headquarters to the Commander-in-Chief of the Soviet Forces in the Far East on the Start of Combat Operations, No. 11122, Signed by [Communist Party General Secretary Joseph] Stalin and [Chief of General Staff A.I.] Antonov, 7 August 1945 (translation by Anna Melyakova)

Source: V. A. Zolotarev, ed.,  Sovetsko-Iaponskaia Voina 1945 Goda: Istoriia Voenno-Politicheskogo Protivoborstva Dvukh Derzhav v 30–40e Gody ( Moscow: Terra, 1997 and 2000), Vol. 7 (1), 340-341.

To keep his pledge at Yalta to enter the war against Japan and to secure the territorial concessions promised at the conference (e.g., Soviet annexation of the Kuriles and southern Sakhalin and a Soviet naval base at Port Arthur, etc.) Stalin considered various dates to schedule an attack. By early August he decided that 9-10 August 1945 would be the best dates for striking Japanese forces in Manchuria. In light of Japan’s efforts to seek Soviet mediation, Stalin wanted to enter the war quickly lest Tokyo reach a compromise peace with the Americans and the British at Moscow’s expense. But on 7 August, Stalin changed the instructions: the attack was to begin the next day. According to David Holloway, “it seems likely that the atomic bombing of Hiroshima the day before that impelled [Stalin] to speed up Soviet entry into the war” and “secure the gains promised at Yalta.” [59]

Document 66 : Memorandum of Conversation, “Atomic Bomb,” August 7, 1945

Source: Library of Congress Manuscript Division, Papers of W. Averell Harriman, box 181, Chron File Aug 5-9, 1945.

The Soviets already knew about the U.S. atomic project from espionage sources in the United States and Britain so Molotov’s comment to Ambassador Harriman about the secrecy surrounding the U.S. atomic project can be taken with a grain of salt, although the Soviets were probably unaware of specific plans for nuclear use.

Documents 67A-B:  Early High-level Reactions to the Hiroshima Bombing

67A : Cabinet Meeting and Togo's Meeting with the Emperor, August 7-8, 1945 Source: Gaimusho (Ministry of Foreign Affairs) ed.  Shusen Shiroku  (The Historical Records of the End of the War), annotated by Jun Eto, volume 4, 57-60 [Excerpts] [Translation by Toshihiro Higuchi]

67B : Admiral Tagaki Diary Entry for Wednesday, August 8 , 1945

Source: Takashi Itoh, ed.,  Sokichi Takagi: Nikki to Joho  [Sokichi Takagi: Diary and Documents] (Tokyo, Japan: Misuzu-Shobo, 2000), 923-924 [Translation by Hikaru Tajima]

Excerpts from the Foreign Ministry's compilation about the end of the war show how news of the bombing reached Tokyo as well as how Foreign Minister's Togo initially reacted to reports about Hiroshima. When he learned of the atomic bombing from the Domei News Agency, Togo believed that it was time to give up and advised the cabinet that the atomic attack provided the occasion for Japan to surrender on the basis of the Potsdam Declaration. Togo could not persuade the cabinet, however, and the Army wanted to delay any decisions until it had learned what had happened to Hiroshima. When the Foreign Minister met with the Emperor, Hirohito agreed with him; he declared that the top priority was an early end to the war, although it would be acceptable to seek better surrender terms--probably U.S. acceptance of a figure-head emperor--if it did not interfere with that goal. In light of those instructions, Togo and Prime Minister Suzuki agreed that the Supreme War Council should meet the next day.  [59a]

An entry from Admiral Tagaki's diary for August 8 conveys more information on the mood in elite Japanese circles after Hiroshima, but before the Soviet declaration of war and the bombing of Nagasaki. Seeing the bombing of Hiroshima as a sign of a worsening situation at home, Tagaki worried about further deterioration. Nevertheless, his diary suggests that military hard-liners were very much in charge and that Prime Minister Suzuki was talking tough against surrender, by evoking last ditch moments in Japanese history and warning of the danger that subordinate commanders might not obey surrender orders. The last remark aggravated Navy Minister Yonai who saw it as irresponsible. That the Soviets had made no responses to Sato's request for a meeting was understood as a bad sign; Yonai realized that the government had to prepare for the possibility that Moscow might not help. One of the visitors mentioned at the beginning of the entry was Iwao Yamazaki who became Minister of the Interior in the next cabinet.

Document 68 : Navy Secretary James Forrestal to President Truman, August 8, 1945

General Douglas MacArthur had been slated as commander for military operations against Japan’s mainland, this letter to Truman from Forrestal shows that the latter believed that the matter was not settled. Richard Frank sees this as evidence of the uncertainty felt by senior officials about the situation in early August; Forrestal would not have been so “audacious” to take an action that could ignite a “political firestorm” if he “seriously thought the end of the war was near.”

Document 69 : Memorandum of Conversation, “Far Eastern War and General Situation,” August 8, 1945, Top Secret

Source: Library of Congress Manuscript Division, Papers of W. Averell Harriman, box 181, Chron File Aug 5-9, 1945

Shortly after the Soviets declared war on Japan, in line with commitments made at the Yalta and Potsdam conferences, Ambassador Harriman met with Stalin, with George Kennan keeping the U.S. record of the meeting. After Stalin reviewed in considerable detail, Soviet military gains in the Far East, they discussed the possible impact of the atomic bombing on Japan’s position (Nagasaki had not yet been attacked) and the dangers and difficulty of an atomic weapons program. According to Hasegawa, this was an important, even “startling,” conversation: it showed that Stalin “took the atomic bomb seriously”; moreover, he disclosed that the Soviets were working on their own atomic program. [60]

Document 70 : Entries for 8-9 August, Robert P. Meiklejohn Diary

Source: W.A. Harriman Papers, Library of Congress, box 211 , Robert Pickens Meiklejohn World War II Diary At London and Moscow March 10, 1941-February 14, 1946 , Volume II (Privately printed, 1980 [Printed from hand-written originals]) (Reproduced with permission)

Robert P. Meiklejohn, who worked as Ambassador W. A. Harriman’s administrative assistant at the U.S. Embassies in Moscow and London during and after World War II, kept a detailed diary of his experiences and observations. The entries for 8 and 9 August, prepared in light of the bombing of Hiroshima, include discussion of the British contribution to the Manhattan Project, Harriman (“his nibs’”) report on his meeting with Molotov about the Soviet declaration of war, and speculation about the impact of the bombing of Hiroshima on the Soviet decision. According to Meiklejohn, “None of us doubt that the atomic bomb speeded up the Soviets’ declaration of war.”

Document 71 : Memorandum of Conference with the President, August 8, 1945 at 10:45 AM

At their first meeting after the dropping of the bomb on Hiroshima, Stimson briefed Truman on the scale of the destruction, with Truman recognizing the “terrible responsibility” that was on his shoulders. Consistent with his earlier attempts, Stimson encouraged Truman to find ways to expedite Japan’s surrender by using “kindness and tact” and not treating them in the same way as the Germans. They also discussed postwar legislation on the atom and the pending Henry D. Smyth report on the scientific work underlying the Manhattan project and postwar domestic controls of the atom.

Documents 72A-C: The Attack on Nagasaki:

72A . Cable APCOM 5445 from General Farrell to O’Leary [Groves assistant], August 9, 1945, Top Secret

72B . COMGENAAF 8 cable CMDW 576 to COMGENUSASTAF, for General Farrell, August 9, 1945, Top secret

72C . COMGENAAF 20 Guam cable AIMCCR 5532 to COMGENUSASTAF Guam, August 10, 1945, Top Secret

Source: RG 77, Tinian Files, April-December 1945, box 20, Envelope G Tinian Files, Top Secret

The prime target for the second atomic attack was Kokura, which had a large army arsenal and ordnance works, but various problems ruled that city out; instead, the crew of the B-29 that carried “Fat Man” flew to an alternate target at Nagasaki. These cables are the earliest reports of the mission; the bombing of Nagasaki killed immediately at least 39,000 people, with more dying later. According to Frank, the “actual total of deaths due to the atomic bombs will never be known,” but the “huge number” ranges somewhere between 100,000 and 200,000 people. Barton J. Bernstein and Martin Sherwin have argued that if top Washington policymakers had kept tight control of the delivery of the bomb instead of delegating it to Groves the attack on Nagasaki could have been avoided. The combination of the first bomb and the Soviet declaration of war would have been enough to induce Tokyo’s surrender. By contrast, Maddox argues that Nagasaki was necessary so that Japanese “hardliners” could not “minimize the first explosion” or otherwise explain it away. [61]

Documents 73A-B: Ramsey Letter from Tinian Island

73A : Letter from Norman Ramsey to J. Robert Oppenheimer, undated [mid-August 1945], Secret, excerpts Source: Library of Congress, J. Robert Oppenheimer Papers, box 60, Ramsey, Norman

73B : Transcript of the letter prepared by editor.

Ramsey, a physicist, served as deputy director of the bomb delivery group, Project Alberta. This personal account, written on Tinian, reports his fears about the danger of a nuclear accident, the confusion surrounding the Nagasaki attack, and early Air Force thinking about a nuclear strike force.

X. Toward Surrender

Document 74 : “Magic” – Far East Summary, War Department, Office of Assistant Chief of Staff, G-2, no. 507, August 9, 1945

Within days after the bombing of Hiroshima, U.S. military intelligence intercepted Japanese reports on the destruction of the city. According to an “Eyewitness Account (and Estimates Heard) … In Regard to the Bombing of Hiroshima”: “Casualties have been estimated at 100,000 persons.”

Document 75 : “Hoshina Memorandum” on the Emperor’s “Sacred Decision [ go-seidan] ,” 9-10 August, 1945

Source: Zenshiro Hoshina,  Daitoa Senso Hishi: Hoshina Zenshiro Kaiso-roku  [Secret History of the Greater East Asia War: Memoir of Zenshiro Hoshina] (Tokyo, Japan: Hara-Shobo, 1975), excerpts from Section 5, “The Emperor made  go-seidan  [= the sacred decision] – the decision to terminate the war,” 139-149 [translation by Hikaru Tajima]

Despite the bombing of Hiroshima, the Soviet declaration of war, and growing worry about domestic instability, the Japanese cabinet (whose decisions required unanimity) could not form a consensus to accept the Potsdam Declaration. Members of the Supreme War Council—“the Big Six” [62] —wanted the reply to Potsdam to include at least four conditions (e.g., no occupation, voluntary disarmament); they were willing to fight to the finish. The peace party, however, deftly maneuvered to break the stalemate by persuading a reluctant emperor to intervene. According to Hasegawa, Hirohito had become convinced that the preservation of the monarchy was at stake. Late in the evening of 9 August, the emperor and his advisers met in the bomb shelter of the Imperial Palace.

Zenshiro Hoshina, a senior naval official, attended the conference and prepared a detailed account. With Prime Minister Suzuki presiding, each of the ministers had a chance to state their views directly to Hirohito. While Army Minister Anami tacitly threatened a coup (“civil war”), the emperor accepted the majority view that the reply to the Potsdam declaration should include only one condition not the four urged by “Big Six.” Nevertheless, the condition that Hirohito accepted was not the one that foreign minister Togo had brought to the conference. What was at stake was the definition of the  kokutai  (national policy). Togo’s proposal would have been generally consistent with a constitutional monarchy because it defined the  kokutai  narrowly as the emperor and the imperial household. What Hirohito accepted, however, was a proposal by the extreme nationalist Kiichiro Hiranuma which drew upon prevailing understandings of the  kokutai : the “mythical notion” that the emperor was a living god. “This was the affirmation of the emperor’s theocratic powers, unencumbered by any law, based on Shinto gods in antiquity, and totally incompatible with a constitutional monarchy.” Thus, the Japanese response to the Potsdam declaration opposed “any demand which prejudices the prerogatives of his Majesty as a sovereign ruler.” This proved to be unacceptable to the Truman administration. [63]

Document 76 :“Magic’ – Far East Summary, War Department, Office of Assistant Chief of Staff, G-2, no. 508, August 10, 1945

More intercepted messages on the bombing of Hiroshima.

Documents 77A-B: The First Japanese Offer Intercepted

77A . “Magic” – Diplomatic Summary, War Department, Office of Assistant Chief of Staff, G-2, No. 1233 – August 10, 1945, Top Secret Ultra

77B . Translation of intercepted Japanese messages, circa 10 August 10, 1945, Top Secret Ultra

The first Japanese surrender offer was intercepted shortly before Tokyo broadcast it. This issue of the diplomatic summary also includes Togo’s account of his notification of the Soviet declaration of war, reports of Soviet military operations in the Far East, and intercepts of French diplomatic traffic. A full translation of the surrender offer was circulated separately. The translations differ but they convey the sticking point that prevented U.S. acceptance: Tokyo’s condition that the allies not make any “demand which prejudices the prerogatives of His Majesty as a sovereign ruler.”

Document 78 : Diary Entry, Friday, August 10, 1945, Henry Wallace Diary

Source: Papers of Henry A. Wallace, Special Collections Department, University of Iowa Libraries, Iowa City, Iowa (copy courtesy of Special Collections Department)

Note: The second page of the diary entry includes a newspaper clipping of the Associated Press’s transmission of the Byrnes note. Unfortunately, AP would not authorize the Archive to reproduce this item without payment. Therefore, we are publishing an excised version of the entry, with a link to the  Byrnes note .

Secretary of Commerce (and former Vice President) Henry Wallace provided a detailed report on the cabinet meeting where Truman and his advisers discussed the Japanese surrender offer, Russian moves into Manchuria, and public opinion on “hard” surrender terms. With Japan close to capitulation, Truman asserted presidential control and ordered a halt to atomic bombings. Barton J. Bernstein has suggested that Truman’s comment about “all those kids” showed his belated recognition that the bomb caused mass casualties and that the target was not purely a military one. [64]

Document 79 : Entries for 10-11 August, Robert P. Meiklejohn Diary

In these entries, Meiklejohn discussed how he and others in the Moscow Embassy learned about the bombing of Nagasaki from the “OWI Bulletin.” Entries for 10 and 11 August cover discussion at the Embassy about the radio broadcast announcing that Japan would surrender as long the Emperor’s status was not affected. Harriman opined that “surrender is in the bag” because of the Potsdam Declaration’s provision that the Japanese could “choose their own form of government, which would probably include the Emperor.” Further, “the only alternative to the Emperor is Communism,” implying that an official role for the Emperor was necessary to preserve social stability and prevent social revolution.

Document 80 : Stimson Diary Entries, Friday and Saturday, August 10 and 11, 1945

Stimson’s account of the events of 10 August focused on the debate over the reply to the Japanese note, especially the question of the Emperor’s status.  The U.S. reply , drafted during the course of the day, did not explicitly reject the note but suggested that any notion about the “prerogatives” of the Emperor would be superceded by the concept that all Japanese would be “Subject to the Supreme Commander of the Allied Powers.” The language was ambiguous enough to enable Japanese readers, upon Hirohito’s urging, to believe that they could decide for themselves the Emperor’s future role. Stimson accepted the language believing that a speedy reply to the Japanese would allow the United States to “get the homeland into our hands before the Russians could put in any substantial claim to occupy and help rule it.” If the note had included specific provision for a constitutional monarchy, Hasegawa argues, it would have “taken the wind out of the sails” of the military faction and Japan might have surrendered several days earlier, on August 11 or 12 instead of August 14. [65]

Document 81 : Entries from Walter Brown Diary, 10-11 August 1945

Source:  Clemson University Libraries, Special Collections, Clemson, SC; Mss 243, Walter Brown Papers, box 68, folder 13, “Transcript/Draft B

Brown recounted Byrnes’ debriefing of the 10 August White House meeting on the Japanese peace offer, an account which differed somewhat from that in the Stimson diary .  According to what Byrnes told Brown, Truman, Stimson, and Leahy favored accepting the Japanese note, but Byrnes objected that the United States should “go [no] further than we were willing to go at Potsdam.” Stimson’s account of the meeting noted Byrnes’ concerns (“troubled and anxious”) about the Japanese note and implied that he (Stimson) favored accepting it, but did not picture the debate as starkly as Browns's did.

Document 82 : General L. R. Groves to Chief of Staff George C. Marshall,  August 10, 1945, Top Secret, with a hand-written note by General Marshall

Source: George C. Marshall Papers, George C. Marshall Library, Lexington, VA (copy courtesy of Barton J. Bernstein)

Groves informed General Marshall that he was making plans for the use of a third atomic weapon sometime after 17 August, depending on the weather. With Truman having ordered a halt to the atomic bombings [See document 78], Marshall wrote on Grove's memo that the bomb was “not to be released over Japan without express authority from the President.”

Document 83 : Memorandum of Conversation, “Japanese Surrender Negotiations,” August 10, 1945, Top Secret

Source: Library of Congress Manuscript Division, Papers of W. Averell Harriman, box 181, Chron File Aug 10-12, 1945

Japan’s prospective surrender was the subject of detailed discussion between Harriman, British Ambassador Kerr, and Soviet Foreign Minister Molotov during the evening of August 10 (with a follow-up meeting occurring at 2 a.m.). In the course of the conversation, Harriman received a message from Washington that included the proposed U.S. reply and a request for Soviet support of the reply. After considerable pressure from Harriman, the Soviets signed off on the reply but not before tensions surfaced over the control of Japan--whether Moscow would have a Supreme Commander there as well. This marked the beginning of a U.S.-Soviet “tug of war” over occupation arrangements for Japan. [66]

Document 84 : Admiral Tagaki Diary Entry for 12 August [1945] Source: Takashi Itoh, ed.,  Sokichi Takagi: Nikki to Joho  [Sokichi Takagi: Diary and Documents] (Tokyo, Japan: Misuzu-Shobo, 2000), 926-927 [Translation by Hikaru Tajima]

As various factions in the government maneuvered on how to respond to the Byrnes note, Navy Minister Yonai and Admiral Tagaki discussed the latest developments. Yonai was upset that Chief of Staff Yoshijiro Umezu and naval chief Suemu Toyada had sent the emperor a memorandum arguing that acceptance of the Brynes note would “desecrate the emperor’s dignity” and turn Japan into virtually a “slave nation.” The emperor chided Umezu and Toyoda for drawing hasty conclusions; in this he had the support of Yonai, who also dressed them down. As Yonai explained to Tagaki, he had also confronted naval vice Chief Takijiro Onishi to make sure that he obeyed any decision by the Emperor. Yonai made sure that Takagi understood his reasons for bringing the war to an end and why he believed that the atomic bomb and the Soviet declaration of war had made it easier for Japan to surrender. [67]

Document 85 : Memorandum from Major General Clayton Bissell, Assistant Chief of Staff, G-2, for the Chief of Staff, “Estimate of Japanese Situation for Next 30 Days,” August 12, 1945, Top Secret

Source: National Archives, RG 165, Army Operations OPD, Executive Files 1940-1945, box 12, Exec #2

Not altogether certain that surrender was imminent, Army intelligence did not rule out the possibility that Tokyo would try to “drag out the negotiations” or reject the Byrnes proposal and continue fighting. If the Japanese decided to keep fighting, G-2 opined that “Atomic bombs will not have a decisive effect in the next 30 days.” Richard Frank has pointed out that this and other documents indicate that high level military figures remained unsure as to how close Japan really was to surrender.

Document 86 : The Cabinet Meeting over the Reply to the Four Powers (August 13)

Source:  Gaimusho [Ministry of Foreign Affairs], ed., Shusen Shiroku [Historical Record of the End of the War] (Tokyo: Hokuyosha, 1977-1978), vol. 5, 27-35 [Translated by Toshihiro Higuchi]

The Byrnes Note did not break the stalemate at the cabinet level. An account of the cabinet debates on August 13 prepared by Information Minister Toshiro Shimamura showed the same divisions as before; Anami and a few other ministers continued to argue that the Allies threatened the  kokutai  and that setting the four conditions (no occupation, etc.) did not mean that the war would continue. Nevertheless, Anami argued, “We are still left with some power to fight.” Suzuki, who was working quietly with the peace party, declared that the Allied terms were acceptable because they gave a “dim hope in the dark” of preserving the emperor. At the end of the meeting, he announced that he would report to Hirohito and ask him to make another “Sacred Judgment”. Meanwhile, junior Army officers plotted a coup to thwart the plans for surrender. [68]

Document 87 : Telephone conversation transcript, General Hull and Colonel Seaman [sic] – 1325 – 13 Aug 45, Top Secret

Source: George C. Marshall Library, Lexington, VA, George C. Marshall Papers (copy courtesy of Barton J. Bernstein)

While Truman had rescinded the order to drop nuclear bombs, the war was not yet over and uncertainty about Japan’s next step motivated war planner General John E. Hull (assistant chief of staff for the War Department’s Operations Division), and one of Groves’ associates, Colonel L. E. Seeman, to continue thinking about further nuclear use and its relationship to a possible invasion of Japan. As Hull explained, “should we not concentrate on targets that will be of greatest assistance to an invasion rather than industry, morale, psychology, etc.” “Nearer the tactical use”, Seaman agreed and they discussed the tactics that could be used for beach landings. In 1991 articles, Barton Bernstein and Marc Gallicchio used this and other evidence to develop the argument that concepts of tactical nuclear weapons use first came to light at the close of World War II. [69]

Document 88 : “Magic” – Diplomatic Summary, War Department, Office of Assistant Chief of Staff, G-2, No. 1236 – August 13, 1945, Top Secret Ultra

The dropping of two atomic bombs, the tremendous destruction caused by U.S. bombing, and the Soviet declaration of war notwithstanding, important elements of the Japanese Army were unwilling to yield, as was evident from intercepted messages dated 12 and 13 August. Willingness to accept even the “destruction of the Army and Navy” rather than surrender inspired the military coup that unfolded and failed during the night of 14 August.

Document 89 : “The Second  Sacred Judgment”, August 14, 1945

Source :   Hiroshi [Kaian) Shimomura, S husenki [Account of the End of the War]  (Tokyo, Kamakura Bunko, [1948], 148-152 [Translated by Toshihiro Higuchi]

Frightened by the rapid movement of Soviet forces into Manchuria and worried that the army might launch a coup, the peace party set in motion a plan to persuade Hirohito to meet with the cabinet and the “Big Six” to resolve the stalemate over the response to the Allies. Japan was already a day late in responding to the Byrnes Note and Hirohito agreed to move quickly. At 10:50 a.m., he met with the leadership at the bomb shelter in his palace. This account, prepared by Director of Information Shimomura, conveys the drama of the occasion (as well as his interest in shifting the blame for the debacle to the Army). After Suzuki gave the war party--Umeda, Toyoda, and Anami--an opportunity to present their arguments against accepting the Byrnes Note, he asked the emperor to speak. 

  Hirohito asked the leadership to accept the Note, which he believed was “well intentioned” on the matter of the “national polity” (by leaving open a possible role for the Emperor).  Arguing that continuing the war would reduce the nation “to ashes,” his words about “bearing the unbearable” and sadness over wartime losses and suffering prefigured the language that Hirohito would use in his public announcement the next day. According to Bix, “Hirohito's language helped to transform him from a war to a peace leader, from a cold, aloof monarch to a human being who cared for his people” but “what chiefly motivated him … was his desire to save a politically empowered throne with himself on it.” [70]

Hirohito said that he would make a recording of the surrender announcement so that the nation could hear it. That evening army officers tried to seize the palace and find Hirohito’s recording, but the coup failed. Early the next day, General Anami committed suicide. On the morning of August 15, Hirohito broadcast the message to the nation (although he never used the word “surrender”). A few weeks later, on September 2, 1945 Japanese representatives signed surrender documents on the USS  Missouri , in Tokyo harbor. [71]

Document 90 : “Magic” – Far East Summary, War Department, Office of Assistant Chief of Staff, G-2, no. 515, August 18, 1945

This summary includes an intercepted account of the destruction of Nagasaki.

Document 91 :Washington Embassy Telegram 5599 to Foreign Office, 14 August 1945, Top Secret [72]

Source: The British National Archives, Records of the Foreign and Commonwealth Office,  FO 800/461

With the Japanese surrender announcement not yet in, President Truman believed that another atomic bombing might become necessary. After a White House meeting on 14 August, British Minister John Balfour reported that Truman had “remarked sadly that he now had no alternative but to order an atomic bomb to be dropped on Tokyo.” This was likely emotional thinking spurred by anxiety and uncertainty. Truman was apparently not considering the fact that Tokyo was already devastated by fire bombing and that an atomic bombing would have killed the Emperor, which would have greatly complicated the process of surrender. Moreover, he may not have known that the third bomb was still in the United States and would not be available for use for nearly another week. [73]  As it turned out, a few hours later, at 4:05 p.m., the White House received the Japanese surrender announcement.

XI. Confronting the Problem of Radiation Poisoning

Document 92 : P.L. Henshaw and R.R. Coveyou to H.J. Curtis and K. Z. Morgan, “Death from Radiation Burns,” 24 August 1945, Confidential

Source: Department of Energy Open-Net

Two scientists at Oak Ridge’s Health Division, Henshaw and Coveyou, saw a United Press report in the Knoxville  News Sentinel  about radiation sickness caused by the bombings. Victims who looked healthy weakened, “for unknown reasons” and many died. Lacking direct knowledge of conditions in Hiroshima and Nagasaki, Henshaw and Coveyou had their own data on the biological effects of radiation and could make educated guesses. After reviewing the impact of various atomic bomb effects--blast, heat, flash radiation (prompt effects from gamma waves), and radiation from radioactive substances--they concluded that “it seems highly plausible that a great many persons were subjected to lethal and sub-lethal dosages of radiation in areas where direct blast effects were possibly non-lethal.” It was “probable,” therefore, that radiation “would produce increments to the death rate and “even more probable” that a “great number of cases of sub-lethal exposures to radiation have been suffered.” [74]

Document 93 : Memorandum of Telephone Conversation Between General Groves and Lt. Col. Rea, Oak Ridge Hospital, 9:00 a.m., August 28, 1945, Top Secret

Source: RG 77, MED Records, Top Secret Documents, File no. 5b

Despite the reports pouring in from Japan about radiation sickness among the victims of Hiroshima and Nagasaki, General Groves and Dr. Charles Rea, a surgeon who was head of the base hospital at Oak Ridge (and had no specialized knowledge about the biological effects of radiation) dismissed the reports as “propaganda”. Unaware of the findings of Health Division scientists, Groves and Rhea saw the injuries as nothing more than “good thermal burns.” [75]

Documents 94A-B: General Farrell Surveys the Destruction

94A . Cable CAX 51813 from  USS Teton  to Commander in Chief Army Forces Pacific Administration, From Farrell to Groves, September 10, 1945, Secret

94B . Cable CAX 51948 from Commander in Chief Army Forces Pacific Advance Yokohoma Japan to Commander in Chief Army Forces Pacific Administration, September 14, 1945, Secret

Source: RG 77, Tinian Files, April-December 1945, box 17, Envelope B

A month after the attacks Groves’ deputy, General Farrell, traveled to Japan to see for himself the destruction of Hiroshima and Nagasaki. His vivid account shows that senior military officials in the Manhattan Project were no longer dismissive of reports of radiation poisoning. As Farrell observed in his discussion of Hiroshima, “Summaries of Japanese reports previously sent are essentially correct, as to clinical effects from single gamma radiation dose.” Such findings dismayed Groves, who worried that the bomb would fall into a taboo category like chemical weapons, with all the fear and horror surrounding them. Thus, Groves and others would try to suppress findings about radioactive effects, although that was a losing proposition. [76]

XII. Eisenhower and McCloy’s Views on the Bombings and Atomic Weapons

Document 95 : Entry for 4 October 1945, Robert P. Meiklejohn Diary

In this entry written several months later, Meiklejohn shed light on what much later became an element of the controversy over the Hiroshima-Nagasaki bombings: whether any high level civilian or military officials objected to nuclear use. Meiklejohn recounted Harriman’s visit in early October 1945 to the Frankfurt-area residence of General Dwight Eisenhower, who was finishing up his service as Commanding General, U.S. Army, European Theater. It was Meiklejohn’s birthday and during the dinner party, Eisenhower and McCloy had an interesting discussion of atomic weapons, which included comments alluding to scientists’ statements about what appears to be the H-bomb project (a 20 megaton weapon), recollection of the early fear that an atomic detonation could burn up the atmosphere, and the Navy’s reluctance to use its battleships to test atomic weapons. At the beginning of the discussion, Eisenhower made a significant statement: he “mentioned how he had hoped that the war might have ended without our having to use the atomic bomb.” The general implication was that prior to Hiroshima-Nagasaki, he had wanted to avoid using the bomb.

Some may associate this statement with one that Eisenhower later recalled making to Stimson. In his 1948 memoirs (further amplified in his 1963 memoirs), Eisenhower claimed that he had “expressed the hope [to Stimson] that we would never have to use such a thing against an enemy because I disliked seeing the United States take the lead in introducing into war something as horrible and destructive as this new weapon was described to be.” That language may reflect the underlying thinking behind Eisenhower’s statement during the dinner party, but whether Eisenhower used such language when speaking with Stimson has been a matter of controversy. In later years, those who knew both thought it unlikely that the general would have expressed misgivings about using the bomb to a civilian superior. Eisenhower’s son John cast doubts about the memoir statements, although he attested that when the general first learned about the bomb he was downcast.

Stimson’s diary mentions meetings with Eisenhower twice in the weeks before Hiroshima, but without any mention of a dissenting Eisenhower statement (and Stimson’s diaries are quite detailed on atomic matters). The entry from Meiklejohn’s diary does not prove or disprove Eisenhower’s recollection, but it does confirm that he had doubts which he expressed only a few months after the bombings. Whether Eisenhower expressed such reservations prior to Hiroshima will remain a matter of controversy. [77]

Document 96:  President Harry S. Truman, Handwritten Remarks for Gridiron Dinner, circa 15 December 1945 [78]

Source: Harry S. Truman Library,  President's Secretary's Files,  Speech Files, 1945-1953,  copy on U.S. National Archives Web Site

On 15 December, President Truman spoke about the atomic bombings in his speech at the annual dinner of the Gridiron Club, organized by bureau chiefs and other leading figures of print media organizations. Besides Truman, guests included New York Governor Thomas Dewey (Republican presidential candidate in 1944 and 1948), foreign ambassadors, members of the cabinet and the Supreme Court, the military high command, and various senators and representatives. The U.S. Marine Band provided music for the dinner and for the variety show that was performed by members of the press.  [79]

In accordance with the dinner’s rules that “reporters are never present,” Truman’s remarks were off-the record. The president, however, wrote in long-hand a text that that might approximate what he said that evening. Pages 12 through 15 of those notes refer to the atomic bombing of Japan:

“You know the most terrible decision a man ever had to make was made by me at Potsdam. It had nothing to do with Russia or Britain or Germany. It was a decision to loose the most terrible of all destructive forces for the wholesale slaughter of human beings. The Secretary of War, Mr. Stimson, and I weighed that decision most prayerfully. But the President had to decide. It occurred to me that a quarter of a million of the flower of our young manhood was worth a couple of Japanese cities, and I still think that they were and are. But I couldn’t help but think of the necessity of blotting out women and children and non-combatants. We gave them fair warning and asked them to quit. We picked a couple of cities where war work was the principle industry, and dropped bombs. Russia hurried in and the war ended.”

Truman characterized the Potsdam Declaration as a “fair warning,” but it was an ultimatum. Plainly he was troubled by the devastation and suffering caused by the bombings, but he found it justifiable because it saved the lives of U.S. troops. His estimate of 250,000 U.S. soldiers spared far exceeded that made by General Marshall in June 1945, which was in the range of 31,000 (comparable to the Battle of Luzon) [See Document 26]. By citing an inflated casualty figure, the president was giving a trial run for the rationale that would become central to official and semi-official discourse about the bombings during the decades ahead. [80]  

Despite Truman’s claim that he made “the most terrible” decision at Potsdam, he assigned himself more responsibility than the historical record supports. On the basic decision, he had simply concurred with the judgments of Stimson, Groves, and others that the bomb would be used as soon as it was available for military use. As for targeting, however, he had a more significant role. At Potsdam, Stimson raised his objections to targeting Japan’s cultural capital, Kyoto, and Truman supported the secretary’s efforts to drop that city from the target list [See Documents 47 and 48].  [81]

Where he had taken significant responsibility was by making a decision to stop the atomic bombings just before the Japanese surrender, thereby asserting presidential control over nuclear weapons

The editor thanks Barton J. Bernstein, J. Samuel Walker, Gar Alperovitz, David Holloway, and Alex Wellerstein for their advice and assistance, and Tsuyoshi Hasegawa for kindly providing copies of some of the Japanese sources that were translated for this compilation. Hasegawa’s book,  Racing the Enemy: Stalin, Truman, and the Surrender of Japan  (Cambridge, Harvard University Press, 2005), includes invaluable information on Japanese sources. David Clark, an archivist at the Harry S. Truman Library, and James Cross, Manuscripts Archivist at Clemson University Library’s Special Collections, kindly provided material from their collections. The editor also thanks Kyle Hammond and Gregory Graves for research assistance and Toshihiro Higuchi and Hikaru Tajima (who then were graduate students in history at Georgetown University and the University of Tokyo respectively), for translating documents and answering questions on the Japanese sources. The editor thanks Anna Melyakova (National Security Archive) for translating Russian language material.

Read the documents

I. background on the u.s. atomic project   documents 1a-c: report of the uranium committee.

Document 1A

National Archives, Records of the Office of Scientific Research and Development, Record Group 227 (hereinafter RG 227), Bush-Conant papers microfilm collection, Roll 1, Target 2, Folder 1, "S-1 Historical File, Section A (1940-1941)."

Document 1B

See description of document 1A.

Document 1C

Document 2A

RG 227, Bush-Conant papers microfilm collection, Roll 1, Target 2, Folder 1, "S-1 Historical File, Section II (1941-1942)

Document 2B

Bush-Conant papers, S-1 Historical File, Reports to and Conferences with the President (1942-1944)

See description of document 2A.

National Archives, Record Group 77, Records of the Army Corps of Engineers (hereinafter RG 77), Manhattan Engineering District (MED), Minutes of the Military Policy Meeting (5 May 1943), Correspondence (“Top Secret”) of the Manhattan Engineer District, 1942-1946, microfilm publication M1109 (Washington, D.C.: National Archives and Records Administration, 1980), Roll 3, Target 6, Folder 23, “Military Policy Committee, Minutes of Meetings”

Before the Manhattan Project had produced any weapons, senior U.S. government officials had Japanese targets in mind. Besides discussing programmatic matters (e.g., status of gaseous diffusion plants, heavy water production for reactors, and staffing at Las Alamos), the participants agreed that the first use could be Japanese naval forces concentrated at Truk Harbor, an atoll in the Caroline Islands. If there was a misfire the weapon would be difficult for the Japanese to recover, which would not be the case if Tokyo was targeted. Targeting Germany was rejected because the Germans were considered more likely to “secure knowledge” from a defective weapon than the Japanese. That is, the United States could possibly be in danger if the Nazis acquired more knowledge about how to build a bomb. [9]

RG 77, Correspondence ("Top Secret") of the Manhattan Engineer District, 1942-1946, file 25M

This memorandum from General Groves to General Marshall captured how far the Manhattan Project had come in less than two years since Bush’s December 1942 report to President Roosevelt. Groves did not mention this but around the time he wrote this the Manhattan Project had working at its far-flung installations over 125,000 people ; taking into account high labor turnover some 485,000 people worked on the project (1 out of every 250 people in the country at that time). What these people were laboring to construct, directly or indirectly, were two types of weapons—a gun-type weapon using U-235 and an implosion weapon using plutonium (although the possibility of U-235 was also under consideration). As the scientists had learned, a gun-type weapon based on plutonium was “impossible” because that element had an “unexpected property”: spontaneous neutron emissions would cause the weapon to “fizzle.” [10] For both the gun-type and the implosion weapons, a production schedule had been established and both would be available during 1945. The discussion of weapons effects centered on blast damage models; radiation and other effects were overlooked.

RG 77, Harrison-Bundy Files (H-B Files), folder 69 (copy from microfilm)

Documents 6A-D: President Truman Learns the Secret

Document 6A

G 77, Commanding General’s file no. 24, tab D

Soon after he was sworn in as president following President Roosevelt’s death, Harry Truman learned about the top secret Manhattan Project from briefings by  Secretary of War Stimson and Manhattan Project chief General Groves (who went through the “back door” to escape the watchful press). Stimson, who later wrote up the meeting in his diary, also prepared a discussion paper, which raised broader policy issues associated with the imminent possession of “the most terrible weapon ever known in human history.”

In a background report prepared for the meeting, Groves provided a detailed overview of the bomb project from the raw materials to processing nuclear fuel to assembling the weapons to plans for using them, which were starting to crystallize. With respect to the point about assembling the weapons, Groves and Stimson informed Truman that the first gun-type weapon “should be ready about 1 August 1945” while an implosion weapon would also be available that month. “The target is and was always expected to be Japan.”  

These documents have important implications for the perennial debate over whether Truman “inherited assumptions” from the Roosevelt administration that the bomb would be used when available or that he made  the  decision to do so.  Alperovitz and Sherwin have argued that Truman made “a real decision” to use the bomb on Japan by choosing “between various forms of diplomacy and warfare.” In contrast, Bernstein found that Truman “never questioned [the] assumption” that the bomb would and should be used. Norris also noted that “Truman’s ”decision” amounted to a decision not to override previous plans to use the bomb.” [12]

Document 6B

Henry Stimson Diary, Sterling Library, Yale University (microfilm at Library of Congress)

See description of document 6A.

Document 6C

Record Group 200, Papers of General Leslie R. Groves, Correspondence 1941-1970, box 3, “F”

Document 6D

RG 77, MED Records, Top Secret Documents, File no. 5g

The force of B-29 nuclear delivery vehicles that was being readied for first nuclear use—the Army Air Force’s 509 th Composite Group—required an operational base in the Western Pacific. In late February 1945, months before atomic bombs were ready for use, the high command selected Tinian, an island in the Northern Marianas Islands, for that base.

Library of Congress, Curtis LeMay Papers, Box B-36

As part of the war with Japan, the Army Air Force waged a campaign to destroy major industrial centers with incendiary bombs. This document is General Curtis LeMay’s report on the firebombing of Tokyo--“the most destructive air raid in history”--which burned down over 16 square miles of the city, killed up to 100,000 civilians (the official figure was 83,793), injured more than 40,000, and made over 1 million homeless. [13] According to the “Foreword,” the purpose of the raid, which dropped 1,665 tons of incendiary bombs, was to destroy industrial and strategic targets “ not to bomb indiscriminately civilian populations.” Air Force planners, however, did not distinguish civilian workers from the industrial and strategic structures that they were trying to destroy.

RG 77, MED Records, Top Secret Documents, File no. 5d (copy from microfilm)

On 27 April, military officers and nuclear scientists met to discuss bombing techniques, criteria for target selection, and overall mission requirements. The discussion of “available targets” included Hiroshima, the “largest untouched target not on the 21 st Bomber Command priority list.” But other targets were under consideration, including Yawata (northern Kyushu), Yokohama, and Tokyo (even though it was practically “rubble.”) The problem was that the Air Force had a policy of “laying waste” to Japan’s cities which created tension with the objective of reserving some urban targets for nuclear destruction. [16]

Document 10

RG 77, MED Records, Top Secret Documents, File no. 5g (copy from microfilm)

As director of Los Alamos Laboratory, Oppenheimer’s priority was producing a deliverable bomb, but not so much the effects of the weapon on the people at the target. In keeping with General Groves’ emphasis on compartmentalization, the Manhattan Project experts on the effects of radiation on human biology were at the MetLab and other offices and had no interaction with the production and targeting units. In this short memorandum to Groves’ deputy, General Farrell, Oppenheimer explained the need for precautions because of the radiological dangers of a nuclear detonation. The initial radiation from the detonation would be fatal within a radius of about 6/10ths of a mile and “injurious” within a radius of a mile. The point was to keep the bombing mission crew safe; concern about radiation effects had no impact on targeting decisions. [17]

Document 11

Scientists and officers held further discussion of bombing mission requirements, including height of detonation, weather, radiation effects (Oppenheimer’s memo), plans for possible mission abort, and the various aspects of target selection, including priority cities (“a large urban area of more than three miles diameter”) and psychological dimension. As for target cities, the committee agreed that the following should be exempt from Army Air Force bombing so they would be available for nuclear targeting: Kyoto, Hiroshima, Yokohama, and Kokura Arsenal. Japan’s cultural capital, Kyoto, would not stay on the list. Pressure from Secretary of War Stimson had already taken Kyoto off the list of targets for incendiary bombings and he would successfully object to the atomic bombing of that city. [18]

Document 12

Document 13

Joseph E. Davies Papers, Library of Congress, box 17, 21 May 1945

Document 14

Harrison-Bundy Files relating to the Development of the Atomic Bomb, 1942-1946, microfilm publication M1108 (Washington, D.C.: National Archives and Records Administration, 1980), File 77: "Interim Committee - International Control."

In what Stimson called the “letter of an honest man,” Oswald C. Brewster sent President Truman a profound analysis of the danger and unfeasibility of a U.S. atomic monopoly. [21] An engineer for the Kellex Corporation, which was involved in the gas diffusion project to enrich uranium, Brewster recognized that the objective was fissile material for a weapon. That goal, he feared, raised terrifying prospects with implications for the “inevitable destruction of our present day civilization.” Once the U.S. had used the bomb in combat other great powers would not tolerate a monopoly by any nation and the sole possessor would be “be the most hated and feared nation on earth.” Even the U.S.’s closest allies would want the bomb because “how could they know where our friendship might be five, ten, or twenty years hence.” Nuclear proliferation and arms races would be certain unless the U.S. worked toward international supervision and inspection of nuclear plants.

Document 15

Document 16

At the end of May General Groves forwarded to Army Chief of Staff Marshall a “Plan of Operations” for the atomic bombings. While that plan has not surfaced, apparently its major features were incorporated in this 29 May 1945 message on the “special functions” of the 509th Composite Group sent from Chief of Staff General Lauris Norstad to General Curtis LeMay, chief of the XXI Bomber Command, headquartered in the Marianas Islands. [21A] The Norstad message reviewed the complex requirements for preparing B-29s and their crew for delivering nuclear weapons.  He detailed the mission of the specially modified B-29s that comprised the  509th Composite Group, the “tactical factors” that applied,  training and rehearsal issues, and the functions of “special personnel” and the Operational Studies Group.  The targets listed—Hiroshima, Kyoto, and Niigato—were those that had been discussed at the Target Committee meeting on 28 May, but Kyoto would be dropped when Secretary Stimson objected (although that would remain a contested matter) and Kokura would eventually be substituted.   As part of the Composite Group’s training to drop “special bombs,” it would practice with facsimiles—the conventionally-armed “Pumpkins.” The 509th Composite Group’s cover story for its secret mission was the preparation for the use of “Pumpkins” in battle.

Document 17

Record Group 107, Office of the Secretary of War, Formerly Top Secret Correspondence of Secretary of War Stimson (“Safe File”), July 1940-September 1945, box 12, S-1

Tacitly dissenting from the Targeting Committee’s recommendations, Army Chief of Staff George Marshall argued for initial nuclear use against a clear-cut military target such as a “large naval installation.” If that did not work, manufacturing areas could be targeted, but only after warning their inhabitants. Marshall noted the “opprobrium which might follow from an ill considered employment of such force.” This document has played a role in arguments developed by Barton J. Bernstein that figures such as Marshall and Stimson were “caught between an older morality that opposed the intentional killing of non-combatants and a newer one that stressed virtually total war.” [22]

Document 18

RG 77, MED Records, H-B files, folder no. 100 (copy from microfilm)

With Secretary of War Stimson presiding, members of the committee heard reports on a variety of Manhattan Project issues, including the stages of development of the atomic project,  problems of secrecy, the possibility of informing the Soviet Union, cooperation with “like-minded” powers, the military impact of the bomb on Japan, and the problem of “undesirable scientists.”  In his comments on a detonation over Japanese targets, Oppenheimer mentioned that the “neutron effect would be dangerous to life for a radius of at least two-thirds of a mile,” but did not mention that the radiation could cause prolonged sickness.

Interested in producing the “greatest psychological effect,” the Committee members agreed that the “most desirable target would be a vital war plant employing a large number of workers and closely surrounded by workers’ houses.”  Bernstein argues that this target choice represented an uneasy endorsement of “terror bombing”-the target was not exclusively military or civilian; nevertheless, worker’s housing would include non-combatant men, women, and children. [23] It is possible that Truman was informed of such discussions and their conclusions, although he clung to a belief that the prospective targets were strictly military.

Document 19

Record Group 165, Records of the War Department General and Special Staffs, American-British-Canadian Top Secret Correspondence, Box 504, “ABC 387 Japan (15 Feb. 45)

George A. Lincoln, chief of the Strategy and Policy Group at U.S. Army’s Operations Department, commented on a memorandum by former President Herbert Hoover that Stimson had passed on for analysis. Hoover proposed a compromise solution with Japan that would allow Tokyo to retain part of its empire in East Asia (including Korea and Japan) as a way to head off Soviet influence in the region. While Lincoln believed that the proposed peace teams were militarily acceptable he doubted that they were workable or that they could check Soviet “expansion” which he saw as an inescapable result of World War II. As to how the war with Japan would end, he saw it as “unpredictable,” but speculated that “it will take Russian entry into the war, combined with a landing, or imminent threat of a landing, on Japan proper by us, to convince them of the hopelessness of their situation.” Lincoln derided Hoover’s casualty estimate of 500,000. J. Samuel Walker has cited this document to make the point that “contrary to revisionist assertions, American policymakers in the summer of 1945 were far from certain that the Soviet invasion of Manchuria would be enough in itself to force a Japanese surrender.” [24]

Document 20

Document 21

Henry Stimson Papers, Sterling Library, Yale University (microfilm at Library of Congress)

Stimson and Truman began this meeting by discussing how they should handle a conflict with French President DeGaulle over the movement by French forces into Italian territory. (Truman finally cut off military aid to France to compel the French to pull back). [25] As evident from the discussion, Stimson strongly disliked de Gaulle whom he regarded as “psychopathic.” The conversation soon turned to the atomic bomb, with some discussion about plans to inform the Soviets but only after a successful test. Both agreed that the possibility of a nuclear “partnership” with Moscow would depend on “quid pro quos”: “the settlement of the Polish, Rumanian, Yugoslavian, and Manchurian problems.”

At the end, Stimson shared his doubts about targeting cities and killing civilians through area bombing because of its impact on the U.S.’s reputation as well as on the problem of finding targets for the atomic bomb. Barton Bernstein has also pointed to this as additional evidence of the influence on Stimson of an “an older morality.” While concerned about the U.S.’s reputation, Stimson did not want the Air Force to bomb Japanese cities so thoroughly that the “new weapon would not have a fair background to show its strength,” a comment that made Truman laugh. The discussion of “area bombing” may have reminded him that Japanese civilians remained at risk from U.S. bombing operations.

Document 22

RG 77, MED Records, H-B files, folder no. 76 (copy from microfilm)

Physicists Leo Szilard and James Franck, a Nobel Prize winner, were on the staff of the “Metallurgical Laboratory” at the University of Chicago, a cover for the Manhattan Project program to produce fuel for the bomb. The outspoken Szilard was not involved in operational work on the bomb and General Groves kept him under surveillance but Met Lab director Arthur Compton found Szilard useful to have around. Concerned with the long-run implications of the bomb, Franck chaired a committee, in which Szilard and Eugene Rabinowitch were major contributors, that produced a report rejecting a surprise attack on Japan and recommended instead a demonstration of the bomb on the “desert or a barren island.” Arguing that a nuclear arms race “will be on in earnest not later than the morning after our first demonstration of the existence of nuclear weapons,” the committee saw international control as the alternative. That possibility would be difficult if the United States made first military use of the weapon. Compton raised doubts about the recommendations but urged Stimson to study the report. Martin Sherwin has argued that the Franck committee shared an important assumption with Truman et al.--that an “atomic attack against Japan would `shock’ the Russians”--but drew entirely different conclusions about the import of such a shock. [26]

Document 23

Record Group 107, Office of the Secretary of War, Formerly Top Secret Correspondence of Secretary of War Stimson (“Safe File”), July 1940-September 1945, box 8, Japan (After December 7/41)

Document 24

Document 25

Document 26

Record Group 218, Records of the Joint Chiefs of Staff, Central Decimal Files, 1942-1945, box 198 334 JCS (2-2-45) Mtg 186th-194th

The record of this meeting has figured in the complex debate over the estimates of casualties stemming from a possible invasion of Japan. While post-war justifications for the bomb suggested that an invasion of Japan could have produced very high levels of casualties (dead, wounded, or missing), from hundreds of thousands to a million, historians have vigorously debated the extent to which the estimates were inflated. [29]

Document 27

Document 28

RG 77, MED, H-B files, folder no. 77 (copy from microfilm)

Document 29

Document 30

RG 107, Office of Assistant Secretary of War Formerly Classified Correspondence of John J. McCloy, 1941-1945, box 38, ASW 387 Japan

Document 31

Document 32

Document 33

Naval Aide to the President Files, box 4, Berlin Conference File, Volume XI - Miscellaneous papers: Japan, Harry S. Truman Presidential Library

On 2 July Stimson presented to President Truman a proposal that he had worked up with colleagues in the War Department, including McCloy, Marshall, and Grew. The proposal has been characterized as “the most comprehensive attempt by any American policymaker to leverage diplomacy” in order to shorten the Pacific War. Stimson had in mind a “carefully timed warning” delivered before the invasion of Japan. Some of the key elements of Stimson’s argument were his assumption that “Japan is susceptible to reason” and that Japanese might be even more inclined to surrender if “we do not exclude a constitutional monarchy under her present dynasty.” The possibility of a Soviet attack would be part of the “threat.” As part of the threat message, Stimson alluded to the “inevitability and completeness of the destruction” which Japan could suffer, but he did not make it clear whether unconditional surrender terms should be clarified before using the atomic bomb. Truman read Stimson’s proposal, which he said was “powerful,” but made no commitments to the details, e.g., the position of the emperor. [32]

Document 34

Record Group 353, Records of Interdepartmental and Intradepartmental Committees, Secretary’s Staff Meetings Minutes, 1944-1947 (copy from microfilm)

Document 35

RG 218, Central Decimal Files, 1943-1945, CCS 381 (6-4-45), Sec. 2 Pt. 5

Document 36

Record Group 59, Decimal Files 1945-1949, 740.0011 PW (PE)/7-1645

Document 37

Henry L. Stimson Papers (MS 465), Sterling Library, Yale University (reel 113) (microfilm at Library of Congress)

Still interested in trying to find ways to “warn Japan into surrender,” this represents an attempt by Stimson before the Potsdam conference, to persuade Truman and Byrnes to agree to issue warnings to Japan prior to the use of the bomb. The warning would draw on the draft State-War proclamation to Japan; presumably, the one criticized by Hull (above) which included language about the emperor. Presumably the clarified warning would be issued prior to the use of the bomb; if the Japanese persisted in fighting then “the full force of our new weapons should be brought to bear” and a “heavier” warning would be issued backed by the “actual entrance of the Russians in the war.” Possibly, as Malloy has argued, Stimson was motivated by concerns about using the bomb against civilians and cities, but his latest proposal would meet resistance at Potsdam from Byrnes and other. [34]

Document 38

IV. The Japanese Search for Soviet Mediation   Documents 39A-B: Magic

Document 39A

National Security Agency Mandatory declassification review release.

Beginning in September 1940, U.S. military intelligence began to decrypt routinely, under the “Purple” code-name, the intercepted cable traffic of the Japanese Foreign Ministry. Collectively the decoded messages were known as “Magic.” How this came about is explained in an internal history of pre-war and World War II Army and Navy code-breaking activities prepared by William F. Friedman , a central figure in the development of U.S. government cryptology during the 20 th century. The National Security Agency kept the ‘Magic” diplomatic and military summaries classified for many years and did not release the entire series for 1942 through August 1945 until the early 1990s. [36]

Document 39B

Record Group 457, Records of the National Security Agency/Central Security Service, “Magic” Diplomatic Summaries 1942-1945, box 18.

Document 40

RG 165, Army Operations OPD Executive File #17, Item 13 (copy courtesy of J. Samuel Walker)

Document 41

Record Group 457, Records of the National Security Agency/Central Security Service, “Magic” Diplomatic Summaries 1942-1945, box 18

Document 42

Document 43

Takashi Itoh, ed., Sokichi Takagi: Nikki to Joho [Sokichi Takagi: Diary and Documents] (Tokyo, Japan: Misuzu-Shobo, 2000), 916-917 [Translation by Hikaru Tajima]

Document 44

L.D. Riabev, ed., Atomnyi Proekt SSSR (Moscow: izd MFTI, 2002), Volume 1, Part 2, 335-336

This 10 July 1945 letter from NKVD director V. N. Merkulov to Beria is an example of Soviet efforts to collect inside information on the Manhattan Project, although not all the detail was accurate. Merkulov reported that the United States had scheduled the test of a nuclear device for that same day, although the actual test took place 6 days later. According to Merkulov, two fissile materials were being produced: element-49 (plutonium), and U-235; the test device was fueled by plutonium. The Soviet source reported that the weight of the device was 3 tons (which was in the ball park) and forecast an explosive yield of 5 kilotons. That figure was based on underestimates by Manhattan Project scientists: the actual yield of the test device was 20 kilotons.

Document 45

RG 77, MED Records, Top Secret Documents, File 5e (copy from microfilm)

An elated message from Harrison to Stimson reported the success of the Trinity Test of a plutonium implosion weapon. The light from the explosion could been seen “from here [Washington, D.C.] to “high hold” [Stimson’s estate on Long Island—250 miles away]” and it was so loud that Harrison could have heard the “screams” from Washington, D.C. to “my farm” [in Upperville, VA, 50 miles away] [42]

Document 46

RG 77, MED Records, Top Secret Documents, File no. 4 (copy from microfilm)

Document 47

Barton J. Bernstein, “Truman at Potsdam: His Secret Diary,” Foreign Service Journal, July/August 1980, excerpts, used with author’s permission. [44]

Some years after Truman’s death, a hand-written diary that he kept during the Potsdam conference surfaced in his personal papers. For convenience, Barton Bernstein’s rendition is provided here but linked here are the scanned versions of Truman’s handwriting on the National Archives’ website (for 15-30 July).

Document 48

An important question that Stimson discussed with Marshall, at Truman’s request, was whether Soviet entry into the war remained necessary to secure Tokyo’s surrender. Marshall was not sure whether that was so although Stimson privately believed that the atomic bomb would provide enough to force surrender (see entry for July 23). This entry has been cited by all sides of the controversy over whether Truman was trying to keep the Soviets out of the war. [46] During the meeting on August 24, discussed above, Stimson gave his reasons for taking Kyoto off the atomic target list: destroying that city would have caused such “bitterness” that it could have become impossible “to reconcile the Japanese to us in that area rather than to the Russians.” Stimson vainly tried to preserve language in the Potsdam Declaration designed to assure the Japanese about “the continuance of their dynasty” but received Truman’s assurance that such a consideration could be conveyed later through diplomatic channels (see entry for July 24). Hasegawa argues that Truman realized that the Japanese would refuse a demand for unconditional surrender without a proviso on a constitutional monarchy and that “he needed Japan’s refusal to justify the use of the atomic bomb.” [47]

Document 49

Clemson University Libraries, Special Collections, Clemson, SC; Mss 243, Walter J. Brown Papers, box 10, folder 12, Byrnes, James F.: Potsdam, Minutes, July-August 1945

The degree to which the typed-up version reflects the original is worth investigating. In any event, historians have used information from the diary to support various interpretations. For example, Bernstein cites the entries for 20 and 24 July to argue that “American leaders did not view Soviet entry as a substitute for the bomb” but that the latter “would be so powerful, and the Soviet presence in Manchuria so militarily significant, that there was no need for actual Soviet intervention in the war.” For Brown's diary entry of 3 August 9 1945 historians have developed conflicting interpretations (See discussion of document 57). [48]

Document 50

Document 51

Naval Historical Center, Operational Archives, James Forrestal Diaries

Secretary of the Navy James Forrestal was a regular recipient of “Magic” intercept reports; this substantial entry reviews the dramatic Sato-Togo exchanges covered in the 22 July “Magic” summary (although Forrestal misdated Sato’s cable as “first of July” instead of the 21 st ). In contrast to Alperovitz’s argument that Forrestal tried to modify the terms of unconditional surrender to give the Japanese an out, Frank sees Forrestal’s account of the Sato-Togo exchange as additional evidence that senior U.S. officials understood that Tokyo was not on the “cusp of surrender.” [49]

Document 52

Joseph E. Davies Papers, Library of Congress, Manuscripts Division, box 19, 29 July 1945

VII. Debates among the Japanese – Late July/Early August 1945

Document 53

In the Potsdam Declaration the governments of China, Great Britain, and the United States) demanded the “unconditional surrender of all Japanese armed forces. “The alternative is prompt and utter destruction.” The next day, in response to questions from journalists about the government’s reaction to the ultimatum, Prime Minister Suzuki apparently said that “We can only ignore [ mokusatsu ] it. We will do our utmost to complete the war to the bitter end.” That, Bix argues, represents a “missed opportunity” to end the war and spare the Japanese from continued U.S. aerial attacks. [51] Togo’s private position was more nuanced than Suzuki’s; he told Sato that “we are adopting a policy of careful study.” That Stalin had not signed the declaration (Truman and Churchill did not ask him to) led to questions about the Soviet attitude. Togo asked Sato to try to meet with Soviet Foreign Minister Molotov as soon as possible to “sound out the Russian attitude” on the declaration as well as Japan’s end-the-war initiative. Sato cabled Togo earlier that he saw no point in approaching the Soviets on ending the war until Tokyo had “concrete proposals.” “Any aid from the Soviets has now become extremely doubtful.”

Document 54

Document 55

Document 56

Document 57

Document 58

RG 457, Summaries of Intercepted Japanese Messages (“Magic” Far East Summary, March 20, 1942 – October 2, 1945), box 7, SRS 491-547

Document 59

VIII. The Execution Order   Documents 60A-D: These messages convey the process of creating and transmitting the execution order to bomb Hiroshima. Possibly not wanting to take responsibility for the first use of nuclear weapons, Army Air Force commanders sought formal authorization from Chief of Staff Marshall who was then in Potsdam

Document 60A

RG 77, MED Records, Top Secret Documents, Files no. 5b and 5e (copies from microfilm)

These messages convey the process of creating and transmitting the execution order to bomb Hiroshima.  Possibly not wanting to take responsibility for the first use of nuclear weapons, Army Air Force commanders sought formal authorization from Chief of Staff Marshall who was then in Potsdam. [55] On 22 July Marshall asked Deputy Chief of Staff Thomas Handy to prepare a draft; General Groves wrote one which went to Potsdam for Marshall’s approval. Colonel John Stone, an assistant to commanding General of the Army Air Forces Henry H. “Hap” Arnold, had just returned from Potsdam and updated his boss on the plans as they had developed. On 25 July Marshall informed Handy that Secretary of War Stimson had approved the text; that same day, Handy signed off on a directive which ordered the use of atomic weapons on Japan, with the first weapon assigned to one of four possible targets—Hiroshima, Kokura, Niigata, or Nagasaki. “Additional bombs will be delivery on the [targets] as soon as made ready by the project staff.”

Document 60B

See description of document 60A.

Document 60C

Document 60D

Document 60E

Document 61

RG 77, MED Records, Top Secret Documents, File no. 5

With more information on the Alamogordo test available, Groves provided Marshall with detail on the destructive power of atomic weapons. Barton J. Bernstein has observed that Groves’ recommendation that troops could move into the “immediate explosion area” within a half hour demonstrates the prevalent lack of top-level knowledge of the dangers of nuclear weapons effects. [56] Groves also provided the schedule for the delivery of the weapons: the components of the gun-type bomb to be used on Hiroshima had arrived on Tinian, while the parts of the second weapon to be dropped were leaving San Francisco. By the end of November over ten weapons would be available, presumably in the event the war had continued.

Document 62A

RG 77, Tinian Files, April-December 1945, box 21 (copies courtesy of Barton Bernstein)

Document 62B

See description of document 62A.

Document 62C

Document 63

RG 77, MED Records, Top Secret Documents, File no. 5b (copy from microfilm)

Document 64

Clemson University Libraries, Special Collections, Clemson, SC; Mss 243, Walter J. Brown Papers, box 68, folder 13, “Transcript/Draft B

Returning from the Potsdam Conference, sailing on the U.S.S. Augusta , Truman learned about the atomic bombing of Hiroshima and announced it twice, first to those in the wardroom (socializing/dining area for commissioned officers), and then to the sailors’ mess. Still unaware of radiation effects, Truman emphasized the explosive yield. Later, he met with Secretary of State Byrnes and they discussed the Manhattan Project’s secrecy and the huge expenditures. Truman, who had been chair of the Senate Special Committee to Investigate the National Defense Program, said that “only on the appeal of Secretary of War Stimson did he refrain and let the War Department continue with the experiment unmolested.”

Document 65

A. Zolotarev, ed., Sovetsko-Iaponskaia Voina 1945 Goda: Istoriia Voenno-Politicheskogo Protivoborstva Dvukh Derzhav v 30–40e Gody (Moscow: Terra, 1997 and 2000), Vol. 7 (1), 340-341.

Document 66

Library of Congress Manuscript Division, Papers of W. Averell Harriman, box 181, Chron File Aug 5-9, 1945.

Documents 67A-B: Early High-level Reactions to the Hiroshima Bombing

Document 67A

Gaimusho (Ministry of Foreign Affairs) ed. Shusen Shiroku (The Historical Records of the End of the War), annotated by Jun Eto, volume 4, 57-60 [Excerpts] [Translation by Toshihiro Higuchi]

Excerpts from the Foreign Ministry's compilation about the end of the war show how news of the bombing reached Tokyo as well as how Foreign Minister's Togo initially reacted to reports about Hiroshima. When he learned of the atomic bombing from the Domei News Agency, Togo believed that it was time to give up and advised the cabinet that the atomic attack provided the occasion for Japan to surrender on the basis of the Potsdam Declaration. Togo could not persuade the cabinet, however, and the Army wanted to delay any decisions until it had learned what had happened to Hiroshima. When the Foreign Minister met with the Emperor, Hirohito agreed with him; he declared that the top priority was an early end to the war, although it would be acceptable to seek better surrender terms--probably U.S. acceptance of a figure-head emperor--if it did not interfere with that goal. In light of those instructions, Togo and Prime Minister Suzuki agreed that the Supreme War Council should meet the next day. [59a]

Document 67B

Takashi Itoh, ed., Sokichi Takagi: Nikki to Joho [Sokichi Takagi: Diary and Documents] (Tokyo, Japan: Misuzu-Shobo, 2000), 923-924 [Translation by Hikaru Tajima]

Document 68

Document 69

Library of Congress Manuscript Division, Papers of W. Averell Harriman, box 181, Chron File Aug 5-9, 1945

Document 70

W.A. Harriman Papers, Library of Congress, box 211, Robert Pickens Meiklejohn World War II Diary At London and Moscow March 10, 1941-February 14, 1946, Volume II (Privately printed, 1980 [Printed from hand-written originals]) (Reproduced with permission)

Document 71

Documents 72A-C: The Attack on Nagasaki

Document 72A

RG 77, Tinian Files, April-December 1945, box 20, Envelope G Tinian Files, Top Secret

Document 72B

See description of document 72A.

Document 72C

Document 73A

Library of Congress, J. Robert Oppenheimer Papers, box 60, Ramsey, Norman

Document 73B

See description of document 73A.

Document 74

Document 75

Zenshiro Hoshina, Daitoa Senso Hishi: Hoshina Zenshiro Kaiso-roku [Secret History of the Greater East Asia War: Memoir of Zenshiro Hoshina] (Tokyo, Japan: Hara-Shobo, 1975), excerpts from Section 5, “The Emperor made go-seidan [= the sacred decision] – the decision to terminate the war,” 139-149 [translation by Hikaru Tajima]

Zenshiro Hoshina, a senior naval official, attended the conference and prepared a detailed account. With Prime Minister Suzuki presiding, each of the ministers had a chance to state their views directly to Hirohito. While Army Minister Anami tacitly threatened a coup (“civil war”), the emperor accepted the majority view that the reply to the Potsdam declaration should include only one condition not the four urged by “Big Six.” Nevertheless, the condition that Hirohito accepted was not the one that foreign minister Togo had brought to the conference. What was at stake was the definition of the kokutai (national policy). Togo’s proposal would have been generally consistent with a constitutional monarchy because it defined the kokutai narrowly as the emperor and the imperial household. What Hirohito accepted, however, was a proposal by the extreme nationalist Kiichiro Hiranuma which drew upon prevailing understandings of the kokutai : the “mythical notion” that the emperor was a living god. “This was the affirmation of the emperor’s theocratic powers, unencumbered by any law, based on Shinto gods in antiquity, and totally incompatible with a constitutional monarchy.” Thus, the Japanese response to the Potsdam declaration opposed “any demand which prejudices the prerogatives of his Majesty as a sovereign ruler.” This proved to be unacceptable to the Truman administration. [63]

Document 76

Document 77A

The first Japanese surrender offer was intercepted shortly before Tokyo broadcast it. This issue of the diplomatic summary also includes Togo’s account of his notification of the Soviet declaration of war, reports of Soviet military operations in the Far East, and intercepts of French diplomatic traffic.

Document 77B

A full translation of the surrender offer was circulated separately. The translations differ but they convey the sticking point that prevented U.S. acceptance: Tokyo’s condition that the allies not make any “demand which prejudices the prerogatives of His Majesty as a sovereign ruler.”

Document 78

Papers of Henry A. Wallace, Special Collections Department, University of Iowa Libraries, Iowa City, Iowa (copy courtesy of Special Collections Department)

Note: The second page of the diary entry includes a newspaper clipping of the Associated Press’s transmission of the Byrnes note. Unfortunately, AP would not authorize the Archive to reproduce this item without payment. Therefore, we are publishing an excised version of the entry, with a link to the Byrnes note .

Document 79

Document 80

Stimson’s account of the events of 10 August focused on the debate over the reply to the Japanese note, especially the question of the Emperor’s status. The U.S. reply , drafted during the course of the day, did not explicitly reject the note but suggested that any notion about the “prerogatives” of the Emperor would be superceded by the concept that all Japanese would be “Subject to the Supreme Commander of the Allied Powers.” The language was ambiguous enough to enable Japanese readers, upon Hirohito’s urging, to believe that they could decide for themselves the Emperor’s future role. Stimson accepted the language believing that a speedy reply to the Japanese would allow the United States to “get the homeland into our hands before the Russians could put in any substantial claim to occupy and help rule it.” If the note had included specific provision for a constitutional monarchy, Hasegawa argues, it would have “taken the wind out of the sails” of the military faction and Japan might have surrendered several days earlier, on August 11 or 12 instead of August 14. [65]

Document 81

Clemson University Libraries, Special Collections, Clemson, SC; Mss 243, Walter Brown Papers, box 68, folder 13, “Transcript/Draft B

Brown recounted Byrnes’ debriefing of the 10 August White House meeting on the Japanese peace offer, an account which differed somewhat from that in the Stimson diary. According to what Byrnes told Brown, Truman, Stimson, and Leahy favored accepting the Japanese note, but Byrnes objected that the United States should “go [no] further than we were willing to go at Potsdam.” Stimson’s account of the meeting noted Byrnes’ concerns (“troubled and anxious”) about the Japanese note and implied that he (Stimson) favored accepting it, but did not picture the debate as starkly as Browns's did.

Document 82

George C. Marshall Papers, George C. Marshall Library, Lexington, VA (copy courtesy of Barton J. Bernstein)

Groves informed General Marshall that he was making plans for the use of a third atomic weapon sometime after 17 August, depending on the weather. With Truman having ordered a halt to the atomic bombings [See document 78], Marshall wrote on Grove's memo that the bomb was “not to be released over Japan without express authority from the President.”

Document 83

Library of Congress Manuscript Division, Papers of W. Averell Harriman, box 181, Chron File Aug 10-12, 1945

Document 84

Takashi Itoh, ed., Sokichi Takagi: Nikki to Joho [Sokichi Takagi: Diary and Documents] (Tokyo, Japan: Misuzu-Shobo, 2000), 926-927 [Translation by Hikaru Tajima]

Document 85

National Archives, RG 165, Army Operations OPD, Executive Files 1940-1945, box 12, Exec #2

Document 86

Gaimusho [Ministry of Foreign Affairs], ed., Shusen Shiroku [Historical Record of the End of the War] (Tokyo: Hokuyosha, 1977-1978), vol. 5, 27-35 [Translated by Toshihiro Higuchi]

The Byrnes Note did not break the stalemate at the cabinet level. An account of the cabinet debates on August 13 prepared by Information Minister Toshiro Shimamura showed the same divisions as before; Anami and a few other ministers continued to argue that the Allies threatened the kokutai and that setting the four conditions (no occupation, etc.) did not mean that the war would continue. Nevertheless, Anami argued, “We are still left with some power to fight.” Suzuki, who was working quietly with the peace party, declared that the Allied terms were acceptable because they gave a “dim hope in the dark” of preserving the emperor. At the end of the meeting, he announced that he would report to Hirohito and ask him to make another “Sacred Judgment”. Meanwhile, junior Army officers plotted a coup to thwart the plans for surrender. [68]

Document 87

George C. Marshall Library, Lexington, VA, George C. Marshall Papers (copy courtesy of Barton J. Bernstein)

Document 88

Document 89

Hiroshi [Kaian) Shimomura, Shusenki [Account of the End of the War] (Tokyo, Kamakura Bunko, [1948], 148-152 [Translated by Toshihiro Higuchi]

Frightened by the rapid movement of Soviet forces into Manchuria and worried that the army might launch a coup, the peace party set in motion a plan to persuade Hirohito to meet with the cabinet and the “Big Six” to resolve the stalemate over the response to the Allies. Japan was already a day late in responding to the Byrnes Note and Hirohito agreed to move quickly. At 10:50 a.m., he met with the leadership at the bomb shelter in his palace. This account, prepared by Director of Information Shimomura, conveys the drama of the occasion (as well as his interest in shifting the blame for the debacle to the Army). After Suzuki gave the war party--Umeda, Toyoda, and Anami--an opportunity to present their arguments against accepting the Byrnes Note, he asked the emperor to speak.

Hirohito asked the leadership to accept the Note, which he believed was “well intentioned” on the matter of the “national polity” (by leaving open a possible role for the Emperor). Arguing that continuing the war would reduce the nation “to ashes,” his words about “bearing the unbearable” and sadness over wartime losses and suffering prefigured the language that Hirohito would use in his public announcement the next day. According to Bix, “Hirohito's language helped to transform him from a war to a peace leader, from a cold, aloof monarch to a human being who cared for his people” but “what chiefly motivated him … was his desire to save a politically empowered throne with himself on it.” [70]

Hirohito said that he would make a recording of the surrender announcement so that the nation could hear it. That evening army officers tried to seize the palace and find Hirohito’s recording, but the coup failed. Early the next day, General Anami committed suicide. On the morning of August 15, Hirohito broadcast the message to the nation (although he never used the word “surrender”). A few weeks later, on September 2, 1945 Japanese representatives signed surrender documents on the USS Missouri , in Tokyo harbor. [71]

Document 90

Document 91

The British National Archives, Records of the Foreign and Commonwealth Office, FO 800/461

With the Japanese surrender announcement not yet in, President Truman believed that another atomic bombing might become necessary. After a White House meeting on 14 August, British Minister John Balfour reported that Truman had “remarked sadly that he now had no alternative but to order an atomic bomb to be dropped on Tokyo.” This was likely emotional thinking spurred by anxiety and uncertainty. Truman was apparently not considering the fact that Tokyo was already devastated by fire bombing and that an atomic bombing would have killed the Emperor, which would have greatly complicated the process of surrender. Moreover, he may not have known that the third bomb was still in the United States and would not be available for use for nearly another week. [73] As it turned out, a few hours later, at 4:05 p.m., the White House received the Japanese surrender announcement.

Document 92

Department of Energy Open-Net

Two scientists at Oak Ridge’s Health Division, Henshaw and Coveyou, saw a United Press report in the Knoxville News Sentinel about radiation sickness caused by the bombings. Victims who looked healthy weakened, “for unknown reasons” and many died. Lacking direct knowledge of conditions in Hiroshima and Nagasaki, Henshaw and Coveyou had their own data on the biological effects of radiation and could make educated guesses. After reviewing the impact of various atomic bomb effects--blast, heat, flash radiation (prompt effects from gamma and neutron radiation), and radiation from radioactive substances--they concluded that “it seems highly plausible that a great many persons were subjected to lethal and sub-lethal dosages of radiation in areas where direct blast effects were possibly non-lethal.” It was “probable,” therefore, that radiation “would produce increments to the death rate and “even more probable” that a “great number of cases of sub-lethal exposures to radiation have been suffered.” [74]

Document 93

RG 77, MED Records, Top Secret Documents, File no. 5b

Document 94A

RG 77, Tinian Files, April-December 1945, box 17, Envelope B

See description of document 94B

Document 94B

XII. Eisenhower and McCloy’s Views on the Bombings and Atomic Weapons

Document 95

Document 96

Harry S. Truman Library, President's Secretary's Files, Speech Files, 1945-1953, copy on U.S. National Archives Web Site

On 15 December, President Truman spoke about the atomic bombings in his speech at the annual dinner of the Gridiron Club, organized by bureau chiefs and other leading figures of print media organizations. Besides Truman, guests included New York Governor Thomas Dewey (Republican presidential candidate in 1944 and 1948), foreign ambassadors, members of the cabinet and the Supreme Court, the military high command, and various senators and representatives. The U.S. Marine Band provided music for the dinner and for the variety show that was performed by members of the press. [79]

Truman characterized the Potsdam Declaration as a “fair warning,” but it was an ultimatum. Plainly he was troubled by the devastation and suffering caused by the bombings, but he found it justifiable because it saved the lives of U.S. troops. His estimate of 250,000 U.S. soldiers spared far exceeded that made by General Marshall in June 1945, which was in the range of 31,000 (comparable to the Battle of Luzon) [See Document 26]. By citing an inflated casualty figure, the president was giving a trial run for the rationale that would become central to official and semi-official discourse about the bombings during the decades ahead. [80]

Despite Truman’s claim that he made “the most terrible” decision at Potsdam, he assigned himself more responsibility than the historical record supports. On the basic decision, he had simply concurred with the judgments of Stimson, Groves, and others that the bomb would be used as soon as it was available for military use. As for targeting, however, he had a more significant role. At Potsdam, Stimson raised his objections to targeting Japan’s cultural capital, Kyoto, and Truman supported the secretary’s efforts to drop that city from the target list [See Documents 47 and 48]. [81]

[1] . The World Wide Web includes significant documentary resources on these events. The Truman Library has published a helpful collection of archival documents , some of which are included in the present collection. A collection of transcribed documents is Gene Dannen’s “ Atomic Bomb: Decision .” For a print collection of documents, see Dennis Merrill ed.,  Documentary History of the Truman Presidency: Volume I: The Decision to Drop the Atomic Bomb on Japan  (University Publications of America, 1995). A more recent collection of documents, along with a bibliography, narrative, and chronology, is Michael Kort’s  The Columbia Guide to Hiroshima and the Bomb  (New York: Columbia University Press, 2007). An important  on-line collection focuses on the air-raids of Japanese cities and bases, providing valuable context for the atomic attacks.

[2] . For the early criticisms and their impact on Stimson and other former officials, see Barton J. Bernstein, “Seizing the Contested Terrain of Early Nuclear History: Stimson, Conant, and Their Allies Explain the Decision to Use the Atomic Bomb,”  Diplomatic History  17 (1993): 35-72, and James Hershberg,  James B. Conant: Harvard to Hiroshima and the Making of the Nuclear Age  (Stanford, Stanford University Press, 1995), 291-301.

For Stimson’s article, see “The Decision to Use the Atomic Bomb,”  Harper’s  194 (February 1947): 97-107. Social critic Dwight MacDonald published trenchant criticisms immediately after Hiroshima-Nagasaki; see  Politics Past: Essays in Political Criticism  (New York: Viking, 1972), 169-180.

[3] . The proposed script for the Smithsonian exhibition can be seen at Philipe Nobile,

Judgment at the Smithsonian  (New York: Matthews and Company, 1995), pp. 1-127. For reviews of the controversy, see Barton J. Bernstein, “The Struggle Over History: Defining the Hiroshima Narrative,” ibid., 128-256, and Charles T. O’Reilly and William A. Rooney,  The Enola Gay and The Smithsonian  (Jefferson, NC: McFarland and Company, 2005).

[4] . For the extensive literature, see the references in J. Samuel Walker , Prompt and Utter Destruction: Truman and the Use of Atomic Bombs against Japan,  Third Edition (Chapel Hill: University of North Carolina Press, 2016) at 131-136, as well as Walker’s, “Recent Literature on Truman’s Atomic Bomb Decision: A Search for Middle Ground,”  Diplomatic History  29 (April 2005): 311-334. For more recent contributions, see Sean Malloy,  Atomic Tragedy: Henry L. Stimson and the Decision to Use the Bomb Against Japan  (Ithaca: Cornell University Press, 2008), Andrew Rotter,  Hiroshima: The World's Bomb  (New York: Oxford, 2008), Campbell Craig and Sergey Radchenko,  The Atomic Bomb and the Origins of the Cold War  (New Haven, Yale University Press, 2008), Wilson D. Miscamble,  The Most Controversial Decision: Truman, the Atomic Bombs, and the Defeat of Japan  (New York: Cambridge University Press, 2011). Also important to take into account is John Dower’s extensive discussion of Hiroshima/Nagasaki in context of the U.S. fire-bombings of Japanese cities in  Cultures of War: Pearl Harbor/Hiroshima/9-11/Iraq  (New York, W. Norton, 2010), 163-285.

[5] . The editor particularly benefited from the source material cited in the following works: Robert S. Norris,  Racing for the Bomb: General Leslie S. Groves, The Manhattan Project’s Indispensable Man  (South Royalton, VT: Steerforth Press, 2002); Gar Alperovitz,  The Decision to Use the Bomb and the Architecture of an American Myth  (New York: Alfred E. Knopf, 1995); Richard B. Frank , Downfall: The End of the Imperial Japanese Empire  (New York: Random House, 1999), Martin Sherwin,  A World Destroyed: Hiroshima and the Origins of the Arm Race  (New York, Vintage Books, 1987), and as already mentioned, Hasegawa’s  Racing the Enemy: Stalin, Truman, and the Surrender of Japan  (Cambridge, Harvard University Press, 2005 ).  Barton J. Bernstein’s numerous articles in scholarly publications (many of them are listed in Walker’s assessment of the literature) constitute an invaluable guide to primary sources. An article that Bernstein published in 1995, “The Atomic Bombings Reconsidered,”  Foreign Affairs  74 (1995), 135-152, nicely summarizes his thinking on the key issues.   Noteworthy publications since 2015 include Michael D. Gordin and G. John Ikenberry, eds., The Age of Hiroshim a (Princeton: Princeton University Press, 2019); Sheldon Garon, “On the Transnational Destruction of Cities: What Japan and the United States Learned from the Bombing of Britain and Germany in the Second World War,” Past and Present 247 (2020): 235-271; Katherine E. McKinney, Scott Sagan, and Allen S. Weiner, “Why the Atomic Bombing of Hiroshima Would Be Illegal Today,” The Bulletin of the Atomic Scientist s 76 (2020); Gregg Mitchell, The Beginning or the End: How Hollywood and America Learned  to Stop Worrying and Love the Bomb (New York: The New Press, 2020); Steve Olson, The Apocalypse Factory: Plutonium and the Making of the Atomic Age (New York: W.W. Norton, 2020); Neil J. Sullivan, The Prometheus Bomb: The Manhattan Project and Government in the Dark  (Lincoln, NE: University of Nebraska Press/Potomac Books, 2016); Alex Wellerstein; Restricted Data: The History of Nuclear Secrecy in the United States,  (Chicago: University of Chicago Press, forthcoming, 2020), a memoir by a Hiroshima survivor, Taniguchi Sumitero, The Atomic  Bomb on My Back: A Life Story of Survival and Activism (Montpelier, VT: Rootstock Publishing, 2020), and a collection of interviews, Cynthia C. Kelly, ed., The Manhattan Project: The Birth of the Atomic Bomb in the Words of Its Creators, Eyewitnesses, and Historians (Black Dog & Leventhal, 2020).

[6] . Malloy (2008), 49-50. For more on the Uranium Committee, the decision to establish the S-1 Committee, and the overall context, see James G. Hershberg , James B. Conant: Harvard to Hiroshima and the Making of the Nuclear Age  (Stanford, Stanford University Press, 1995), 140-154.

[7] . Sean Malloy, “`A Very Pleasant Way to Die’: Radiation Effects and the Decision to Use the Atomic Bomb against Japan,”  Diplomatic History  36 (2012), especially 523. For an important study of how contemporary officials and scientists looked at the atomic bomb prior to first use in Japan, see Michael D. Gordin,  Five Days in August: How World War II Became a Nuclear War  (Princeton: Princeton University Press, 2007).

[8] . Norris, 169.

[9] . Malloy (2008), 57-58.

[10] . See also Norris, 362.

[11] . For discussion of the importance of this memorandum, see Sherwin, 126-127, and Hershberg , James B. Conant , 203-207.

[12] . Alperovitz, 662; Bernstein (1995), 139; Norris, 377.

[13] . Quotation and statistics from Thomas R. Searle, “`It Made a Lot of Sense to Kill Skilled Workers’: The Firebombing of Tokyo in March 1945,  The Journal of Military History  55 (2002):103. More statistics and a detailed account of the raid is in Ronald Schaffer,  Wings of Judgment: American Bombing in World War II  (New York: Oxford University Press, 1985), 130-137.

[14] . Searle, “`It Made a Lot of Sense to Kill Skilled Workers,’” 118. For detailed background on the Army Air Force’s incendiary bombing planning, see Schaffer (1985) 107-127. On Stimson, see Schaffer (1985), 179-180 and Malloy (2008), 54. For a useful discussion of the firebombing of Tokyo and the atomic bombings, see Alex Wellerstein, “Tokyo vs. Hiroshima,”  Restricted Data: The Nuclear Secrecy Blog ,  22 September 2014

[15] . See for example, Bernstein (1995), 140-141.

[16] . For useful discussion of this meeting and the other Target Committee meetings, see Norris, 382-386.

[17] . Malloy, “A Very Pleasant Way to Die,” 531-534.

[18] . Schaffer,  Wings of Judgment , 143-146.

[19] . Alperovitz argues that the possibility of atomic diplomacy was central to the thinking of Truman and his advisers, while Bernstein, who argues that Truman’s primary objective was to end the war quickly, suggests that the ability to “cow other nations, notably the Soviet Union” was a “bonus” effect. See Bernstein (1995), 142.

[20] . Alperovitz, 147; Robert James Maddox,  Weapons for Victory: The Hiroshima Decision Fifty Years Later  (Columbia: University of Missouri Press, 1995), 52; Gabiel Kolko,  The Politics of War: The World and United States Foreign Policy, 1943-1945  (New York: Pantheon Books, 1990), 421-422. As Alperovitz notes, the Davies papers include variant diary entries and it is difficult to know which are the most accurate.

[21] . Malloy (2008), 112

[21A] . Vincent Jones, Manhattan: The Army and the Atomic Bomb (Washington, D.C.: U.S. Army Center of Military History, 1985), 529.

[22] . Bernstein (1995), 146. See also Barton J. Bernstein, “Looking Back: Gen. Marshall and the Atomic Bombing of Japanese Cities,” Arms Control Today , November 2015.

[23] . Bernstein (1995), 144. See also Malloy (2008), at 116-117, including the argument that 1) Stimson was deceiving himself by accepting the notion that a “vital war plant …surrounded by workers’ houses” was a legitimate military target, and 2) that Groves was misleading Stimson by withholding the Target Committee’s conclusions that the target would be a city center.

[24] . Walker (2005), 320.

[25] . Frank Costigliola,  France and the United States: The Cold Alliance Since World War II  (New York, Twayne, 1992), 38-39.

[26] . Barton J. Bernstein, Introduction to Helen S. Hawkins et al. editors,  Toward a Livable World: Leo Szilard and the Crusade for Nuclear Arms Control  (Cambridge: MIT Press, 1987), xxx-xxv; Sherwin, 210-215.

[27] . Herbert P. Bix,  Hirohito and the Making of Modern Japan  (New York: HarperCollins Publishers, 2000), 523.

[28] . Walker (2005), 319-320.

[29] . For a review of the debate on casualty estimates, see Walker (2005), 315, 317-318, 321, 323, and 324-325.

[30] . Hasegawa, 105; Alperovitz, 67-72; Forrest Pogue,  George C. Marshall: Statesman, 1945-1959  (New York: Viking, 1987), 18. Pogue only cites the JCS transcript of the meeting; presumably, an interview with a participant was the source of the McCloy quote.

[31] . Alperovitz, 226; Bernstein, “Understanding the Atomic Bomb and the Japanese Surrender,”  Diplomatic History  19 (1995), 237, note 22.

[32] . Malloy (2008), 123-124.

[33] . Alperovitz, 242, 245; Frank, 219.

[34] . Malloy (2008), 125-127.

[35] . Bernstein, introduction,  Toward a Livable World , xxxvii-xxxviii.

[36] . “Magic” summaries for post-August 1945 remain classified at the National Security Agency. Information from the late John Taylor, National Archives. For background on Magic and the “Purple” code, see John Prados,  Combined Fleet Decoded: The Secret History of American Intelligence and the Japanese Navy in World War II (  New York: Random House, 1995), 161-172 and David Kahn,  The Codebreakers: The Story of Secret Writing  (New York: Scribner, 1996), 1-67.

[37] . Alperovitz, 232-238.

[38] . Maddox, 83-84; Hasegawa, 126-128. See also Walker (2005), 316-317.

[39] . Hasegawa, 28, 121-122.

[40] . Peter Grose,  Gentleman Spy: The Life of Allen Dulles  (Boston: Houghton Mifflin, 1994), 170-174, 248-249.

[41] . David Holloway, “Barbarossa and the Bomb: Two Cases of Soviet Intelligence in World War II,” in Jonathan Haslam and Karina Urbach, eds.,  Secret Intelligence in the European States System, 1918-1989  (Stanford: Stanford University Press, 2014), 63-64. For the inception of the Soviet nuclear program and the role of espionage in facilitating it, see Holloway,  Stalin and the Bomb  (New Haven, Yale University Press, 1994).

[42] . For the distances, see Norris, 407.

[43] . For on-line resources on the first atomic test .

[44] . Bernstein’s detailed commentary on Truman’s diary has not been reproduced here except for the opening pages where he provides context and background.

[45] . Frank, 258; Bernstein (1995), 147; Walker (2005), 322. See also Alex Wellerstein’s “ The Kyoto Misconception ”

[46] . Maddox, 102; Alperovitz, 269-270; Hasegawa, 152-153.

[47] . Hasegawa, 292.

[48] . Bernstein, “Understanding the Atomic Bomb and the Japanese Surrender,”  Diplomatic History  19 (1995), 146-147; Alperovitz, 415; Frank, 246.

[49] . Alperovitz, 392; Frank, 148.

[50] . Alperovitz, 281-282. For Davies at Potsdam, see Elizabeth Kimball MacLean,  Joseph E. Davies: Envoy to the Soviets  (Westport, CT: Praeger, 1992), 151-166

[51] . Hasegawa, 168; Bix, 518.

[52] . Bix, 490, 521.

[53] . Alperovitz, 415; Frank, 246.

[54] . Frank, 273-274; Bernstein, “The Alarming Japanese Buildup on Southern Kyushu, Growing U.S. Fears and Counterfactual Analysis: Would the Planned November 1945 Invasion of Southern Kyushu Have Occurred?”  Pacific Historical Review  68 (1999): 561-609.

[55] . Maddox, 105.

[56] . Barton J. Bernstein, "'Reconsidering the 'Atomic General': Leslie R. Groves,"  The Journal of Military History  67 (July 2003): 883-920. See also Malloy, “A Very Pleasant Way to Die,” 539-540.

[57] . For casualty figures and the experience of people on the ground, see Frank, 264-268 and 285-286, among many other sources. Drawing on contemporary documents and journals, Masuji Ibuse’s novel  Black Rain  (Tokyo, Kodansha, 1982) provides an unforgettable account of the bombing of Hiroshima and its aftermath. For early U.S. planning to detonate the weapon at a height designed to maximize destruction from mass fires and other effects, see Alex Wellerstein, “ The Height of the Bomb .”

[58] . Sadao Asada, “The Shock of the Atomic Bomb and Japan’s Decision to Surrender: A Reconsideration,”  Pacific Historical Review  67 (1998): 101-148; Bix, 523; Frank, 348; Hasegawa, 298. Bix appears to have moved toward a position close to Hasegawa’s; see Bix, “Japan's Surrender Decision and the Monarchy: Staying the Course in an Unwinnable War,”  Japan Focus  . For emphasis on the “shock” of the atomic bomb, see also Lawrence Freedman and Saki Dockrill, “Hiroshima: A Strategy of Shock,” in Saki Dockrill, ed.,  From Pearl Harbor to Hiroshima : the Second World War in Asia and the Pacific, 1941-1945  (New York, St. Martin’s Press, 1994), 191-214. For more on the debate over Japan’s surrender, see Hasegawa’s important edited book,  The End of the Pacific War: A Reappraisal  (Stanford: Stanford University Press, 2007), with major contributions by Hasegawa, Holloway, Bernstein, and Hatano.

[59] . Melvyn P. Leffler, “Adherence to Agreements: Yalta and the Experiences of the Early Cold War,”  International Security  11 (1986): 107; Holloway, “Barbarossa and the Bomb,” 65.

[59a] . For more on these developments, see Asada, "The Shock of the Atomic Bomb and Japan's Decision to Surrender: A Reconsideration," 486-488.

[60] . Hasegawa, 191-192.

[61] . Frank, 286-287; Sherwin, 233-237; Bernstein (1995), 150; Maddox, 148.

[62] . The Supreme War Council comprised the prime minister, foreign minister, army and navy ministers, and army and navy chiefs of staff; see Hasegawa, 72 .

[63] . For the maneuverings on August 9 and the role of the  kokutai , see Hasegawa, 3-4, 205-214

[64] . For Truman’s recognition of mass civilian casualties, see also his  letter to Senator Richard Russell, 9 August 1945.

[65] . Hasegawa, 295.

[66] . For “tug of war,” see Hasegawa, 226-227.

[67] . Hasegawa, 228-229, 232.

[68] . Hasegawa, 235-238.

[69] . Barton J. Bernstein, “Eclipsed by Hiroshima and Nagasaki: Early Thinking about Tactical Nuclear Weapons,”  International Security  15 (Spring 1991): 149-173; Marc Gallicchio, “After Nagasaki: General Marshall’s Plans for Tactical Nuclear Weapons in Japan,”  Prologue  23 (Winter 1991): 396-404. Letters from Robert Messer and Gar Alperovitz, with Bernstein’s response, provide insight into some of the interpretative issues. “Correspondence,”  International Security  16 (Winter 1991/1992): 214-221.

[70] . Bix, “Japan's Surrender Decision and the Monarchy: Staying the Course in an Unwinnable War,”  Japan Focus .

[71] . For Hirohito' surrender speech--the actual broadcast and a translation--see  Japan Times , August 2015.

[72] . Cited by Barton J. Bernstein, “Eclipsed by Hiroshima and Nagasaki: Early Thinking About Tactical Nuclear Weapons,”  International Security  15 (1991) at page 167. Thanks to Alex Wellerstein for the suggestion and the archival link.

[73] . For further consideration of Tokyo and more likely targets at the time, see Alex Wellerstein, “Neglected Niigata,”  Restricted Data: The Nuclear Secrecy Blog, 9 October 2015.

[74] . See Malloy, “A Very Pleasant Way to Die,” 541-542.

[75] . For Groves and the problem of radiation sickness, see Norris, 339-441, Bernstein, “Reconsidering the ‘Atomic General’: Leslie R. Groves,”  Journal of Military History  67 (2003), 907-908, and Malloy, “A Very Pleasant Way to Die,” 513-518 and 539-542

[76] . See Janet Farrell Brodie, “Radiation Secrecy and Censorship after Hiroshima and Nagasaki,”  The Journal of Social History  48 (2015): 842-864.

[77] . For Eisenhower’s statements, see  Crusade in Europe  (Garden City: Doubleday, 1948), 443, and  Mandate for Change  (Garden City: Doubleday, 1963), 312-313. Barton J. Bernstein’s 1987 article, “Ike and Hiroshima: Did He Oppose It?”  The Journal of Strategic Studies  10 (1987): 377-389, makes a case against relying on Eisenhower’s memoirs and points to relevant circumstantial evidence. For a slightly different perspective, see Malloy (2007), 138

[78] . Cited in Barton J. Bernstein, “Truman and the A-Bomb: Targeting Noncombatants, Using the Bomb, and His Defending the "Decision,”  The Journal of Military History  62 (1998), at page 559. Thanks to Alex Wellerstein for the suggestion and the archival link.

[79] . “Truman Plays Part of Himself in Skit at Gridiron Dinner,” and “List of Members and Guests at the Gridiron Show,”  The Washington Post , 16 December 1945.

[80] . For varied casualty figures cited by Truman and others after the war, see Walker,  Prompt and Utter Destruction: Truman and the Use of Atomic Bombs Against Japan , 101-102.

[81] . See also ibid., 59.

Why Was the Decision Made to Use the Atomic Bomb on Japan?

The decision to use the atomic bomb to attack two Japanese cities and effectively end World War II remains one of the most controversial decisions in history. The conventional view, going back to the initial press coverage in 1945, was that the use of atomic weapons was justified as it ended a long and very costly war. However, over the intervening decades, other interpretations of the decision to strike two Japanese cities have been offered.

Alternative explanations include the idea that the United States was largely interested in using atomic weapons as a way of ending the war quickly and keeping the Soviet Union from getting involved in the fighting in the Pacific.

Fast Facts: Decision to Drop the Atomic Bomb

• President Truman made the decision to use the atomic bomb with no public or congressional debate. He later formed a group known as the Interim Committee to decide how—but not whether—the bomb should be used.
• A small group of renowned scientists, including some involved in the creation of the bomb, advocated against its use, but their arguments were essentially ignored.
• The Soviet Union was set to enter the war in Japan within months, but the Americans were wary of Soviet intentions. Ending the war quickly would prevent Russian participation in the fighting and expansion into parts of Asia.
• In the Potsdam Declaration, issued on July 26, 1945, the United States made a call for the unconditional surrender of Japan. Japan's rejection of the demand led to final order to proceed with atomic bombing.

Truman's Options

When Harry Truman became president after the death of  Franklin D. Roosevelt  in April 1945, he was informed of a momentous and extraordinarily secret project: the development of the first atomic bomb. A group of scientists had approached Roosevelt years earlier, expressing fear that Nazi scientists would develop an atomic bomb. Eventually, the  Manhattan Project  was organized to create an American super weapon fueled by an atomic reaction.

By the time Truman was informed of the Manhattan Project, Germany was nearly defeated. The remaining enemy of the United States, Japan, continued fighting in an incredibly bloody war in the Pacific. In early 1945, campaigns on  Iwo Jima  and  Okinawa  proved very costly. Japan was being heavily bombed by formations of a new bomber, the  B-29 . Despite heavy casualties, especially among Japanese civilians killed in an American incendiary bombing campaign, the Japanese government seemed intent on continuing the war.

In the spring of 1945, Truman and his military advisers had two obvious options. They could resolve to fight a prolonged war against Japan, which would probably mean having to invade the Japanese home islands in late 1945 and perhaps even continue fighting into 1946 or beyond. Or they could continue working on acquiring a functional atomic bomb and seek to end the war with devastating attacks on Japan.

Lack of Debate

Before the atomic bomb was used for the first time there was no debate in Congress or among the American public. There was a simple reason for that: almost no one in Congress had been aware of the Manhattan Project, and the public had no inkling that a weapon that could end the war was on the horizon. Even the many thousands who worked on the project at various labs and secret facilities were unaware of the ultimate purpose of their labor.

Yet in the summer of 1945, as the atomic bomb was being prepared for its final testing, a closely contained debate over its use did emerge within the circle of scientists who had contributed to its development.  Leo Szilard , a refugee Hungarian physicist who had petitioned President Roosevelt to begin work on the bomb years earlier, had grave concerns.

The main reason Szilard had urged the United States to begin work on the atomic bomb was his fear that Nazi scientists would develop nuclear weapons first. Szilard and other European scientists who worked on the project for the Americans had considered the use of the bomb against the Nazis to be legitimate. But with Germany’s surrender in May 1945, they had concerns about using the bomb against Japan, which did not seem to be developing its own atomic weapons.

Szilard and physicist James Franck submitted a report to Secretary of War Henry L. Stimson in June 1945. They argued that the bomb should be not be used against Japan without warning, and that a demonstration explosion should be arranged so the Japanese leadership could understand the threat. Their arguments were essentially ignored.

The Interim Committee

The secretary of war formed a group called the Interim Committee, which was tasked with deciding how the bomb was to be used. The issue of whether it should be used was not really an issue. The thinking in the highest levels of the Truman administration and the military was quite clear: if the atomic bomb could shorten the war, it should be used.

The Interim Committee, which comprised government officials, military officers, scientists, and even a public relations expert, determined that targets for atomic bombs should be a military-industrial facility deemed important to Japan’s war-related industries. Defense factories tended to be located in or near cities, and would naturally be located not far from housing for many civilian workers.

So it was always assumed that civilians would be in the target zone, but that was not unusual in the context of the war. Many thousands of civilians had died in the Allied bombing of Germany, and the firebombing campaign against Japan in early 1945 had already killed as many as a half-million Japanese civilians.

Timing and the Soviet Union

As the world’s first atomic bomb was being readied for a test blast in a remote desert area of New Mexico in July 1945, President Truman traveled to Potsdam, a suburb of Berlin, to meet with Britain’s Prime Minister Winston Churchill and the Soviet dictator Joseph Stalin . Churchill had known the Americans had been working on the bomb. Stalin had been officially kept in the dark, though Soviet spies working within the Manhattan Project had been passing along information that a major weapon was being developed.

One of Truman’s considerations at the Potsdam Conference was the entry of the Soviet Union into the war against Japan. The Soviets and the Japanese were not at war, and were actually adhering to a non-aggression pact signed years earlier. In meetings with Churchill and President Roosevelt at the Yalta Conference in early 1945, Stalin had agreed that the Soviet Union would attack Japan three months after the surrender of Germany. As Germany had surrendered on May 8, 1945, that placed the Soviet Union's entry into the Pacific war on August 8, 1945.

As Truman and his advisers saw it, Russian help fighting Japan would be welcomed if the Americans would be facing more years of grueling combat. However, the Americans were very wary of Soviet intentions. Seeing the Russians acquire influence over Eastern Europe, there was a great interest in preventing Soviet expansion into parts of Asia.

Truman knew that if the bomb worked and could possibly end the war quickly, he could prevent widespread Russian expansion in Asia. So when a coded message reached him in Potsdam informing him that the bomb test was successful, he could engage Stalin with greater confidence. He knew he would not need Russian help to defeat Japan.

In his handwritten journal, Truman jotted down his thoughts in Potsdam on July 18, 1945. After describing a conversation with Stalin, he noted, “Believe Japs will fold up before Russia comes in. I am sure they will when Manhattan [referring to the Manhattan Project] appears over their homeland.”

Surrender Demand

At the Potsdam conference, the United States issued a call for unconditional surrender of Japan. In the Potsdam Declaration, issued on July 26, 1945, the United States, Great Britain, and the Republic of China argued that Japan’s position was futile and its armed forces should surrender unconditionally. The document’s final sentence stated: “The alternative for Japan is prompt and utter destruction.” No specific mention was made of the atomic bomb.

On July 29, 1945, Japan rejected the Potsdam Declaration.

The United States had two atomic bombs ready to use. A target list of four cities had been determined, and it was decided that the bombs would be used after August 3, 1945, as weather permitted. 

The first atomic bomb was dropped on the city of Hiroshima on August 6, 1945. Its destruction was enormous, but Japan still did not appear willing to surrender. On the morning of August 6 in America, radio stations played a recorded address by President Truman. He announced the use of the atomic bomb and issued a warning to the Japanese that more atomic bombs could be used against their homeland. 

The Japanese government continued to reject calls for surrender. The city of Nagasaki was attacked with another atomic bomb on August 9, 1945. Whether or not the dropping of the second atomic bomb was necessary has long been debated.

Controversy Endures

Over the decades, it was generally taught that the use of the atomic bomb was to end the war. However, over time the issue of its use being part of an American strategy to contain the Soviet Union has also gained credence.

A national controversy over the decision to use the atomic bomb erupted in the mid-1990s, when the Smithsonian Institution made changes to a proposed exhibit featuring the Enola Gay, the B-29 that dropped the Hiroshima bomb. As originally planned, the exhibit would have included criticism of the decision to drop the bomb. Veterans groups, arguing that the use of the bomb saved the lives of troops who would have died in combat during an invasion of combat, protested the planned exhibit.

• Cheek, Dennis W. "Atomic Bomb." Encyclopedia of Science, Technology, and Ethics , edited by Carl Mitcham, vol. 1, Macmillan Reference USA, 2005, pp. 134-137. Gale Virtual Reference Library .
• Fussell, Paul. "The Atomic Bombings Ended the Savagery of Both Sides." The Atomic Bombings of Hiroshima and Nagasaki , edited by Sylvia Engdahl, Greenhaven Press, 2011, pp. 66-80. Perspectives on Modern World History. Gale Virtual Reference Library .
• Bernstein, Barton J. "Atomic Bomb." Ethics, Science, Technology, and Engineering : A Global Resource , edited by J. Britt Holbrook, 2nd ed., vol. 1, Macmillan Reference USA, 2015, pp. 146-152. Gale Virtual Reference Library .

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Harry truman’s decision to use the atomic bomb, the decision.

United States Army Air Corps; Harry S. Truman Library & Museum

By August, 1945, Japan had lost World War II.  Japan and the United States both knew it.  How long would it be, however, before Japan surrendered?  Japan was split between surrender or fighting to the end.  They chose to fight.

In mid-July, President Harry S Truman was notified of the successful test of the atomic bomb, what he called “the most terrible bomb in the history of the world.”  Thousands of hours of research and development as well as billions of dollars had contributed to its production.  This was no theoretical research project.  It was created to destroy and kill on a massive scale.  As president, it was Harry Truman’s decision if the weapon would be used with the goal to end the war.  “It is an awful responsibility that has come to us,” the president wrote.

President Truman had four options:  1) continue conventional bombing of Japanese cities; 2) invade Japan; 3) demonstrate the bomb on an unpopulated island; or, 4) drop the bomb on an inhabited Japanese city.

Option 1: Conventional Bombing of the Japanese Home Islands

While the United States began conventional bombing of Japan as early as 1942, the mission did not begin in earnest until mid-1944.  Between April 1944 and August, 1945, an estimated 333,000 Japanese people were killed and 473,000 more wounded in air raids.  A single firebombing attack on Tokyo in March 1945 killed more than 80,000 people.  Truman later remarked, “Despite their heavy losses at Okinawa and the firebombing of Tokyo, the Japanese refused to surrender.  The saturation bombing of Japan took much fiercer tolls and wrought far and away more havoc than the atomic bomb.  Far and away.  The firebombing of Tokyo was one of the most terrible things that ever happened, and they didn't surrender after that although Tokyo was almost completely destroyed.”

In August 1945, it was clear that conventional bombing was not effective.

Option 2: Ground Invasion of the Japanese Home Islands

The United States could launch a traditional ground invasion of the Japanese home islands.  However, experience showed that the Japanese did not easily surrender.  They had been willing to make great sacrifices to defend the smallest islands.  They were likely to fight even more fiercely if the United States invaded their homeland.  During the battle at Iwo Jima in 1945, 6,200 US soldiers died.  Later that year, on Okinawa, 13,000 soldiers and sailors were killed.  Casualties on Okinawa were 35 percent; one out of three US participants was wounded or killed.  Truman was afraid that an invasion of Japan would look like "Okinawa from one end of Japan to the other."  Casualty predictions varied, but all were high.  The price of invasion would be millions of American dead and wounded.

Estimates did not include Japanese casualties.  Truman and his military advisers assumed that a ground invasion would “be opposed not only by the available organized military forces of the Empire, but also by a fanatically hostile population."   Documents discovered after the war indicated that they were right.  Despite knowing the cause was hopeless, Japan planned a resistance so ferocious, resulting in costs so appalling, that they hoped that the United States would simply call for a cease fire where each nation would agree to stop fighting and each nation would retain the territory they occupied at the time.  Almost one-quarter million Japanese casualties were expected in the invasion.  Truman wrote, “My object is to save as many American lives as possible but I also have a human feeling for the women and children of Japan.”  

In August 1945, it appeared inevitable that Japanese civilians would have to suffer more death and casualties before surrender.  A ground invasion would result in excessive American casualties as well.

Option 3: Demonstration of the Atomic Bomb on an Unpopulated Area

Another option was to demonstrate the power of atomic bomb to frighten the Japanese into surrendering.  An island target was considered, but it raised several concerns.  First, who would Japan select to evaluate the demonstration and advise the government?  A single scientist?  A committee of politicians?  How much time would elapse before Japan communicated its decision—and how would that time be used?  To prepare for more fighting?  Would a nation surrender based on the opinion of a single person or small group?  Second, what if the bomb turned out to be a dud?  This was a new weapon, not clearly understood.  The world would be watching the demonstration of a new weapon so frightening that an enemy would surrender without a fight.  What if this “super weapon” didn’t work?  Would that encourage Japan to fight harder?  Third, there were only two bombs in existence at the time.  More were in production, but, dud or not, was it worth it to expend 50% of the country’s atomic arsenal in a demonstration?

In May 1945, Truman had formed the Interim Committee, a committee to advise the president about matters pertaining to the use of nuclear energy and weapons.  The Committee’s first priority was to advise on the use of the atomic bomb.  After prolonged debate, the president received the Committee’s historic conclusion:  “We can propose no technical demonstration likely to bring an end to the war.  We can see no acceptable alternative to direct military use.”

Option 4: Use of the Atomic Bomb on a Populated Area

Truman and his advisors concluded that only bombing a city would make an adequate impression.  Any advance warning to evacuate a city would endanger the bomber crews; the Japanese would be forewarned and attempt to shoot them down.  The target cities were carefully chosen.  First, it had to be a city that had suffered little damage from conventional bombing so it couldn’t be argued that the damage came from anything other than the atomic bomb.  Second, it must be a city primarily devoted to military production.  This was complicated, however, because in Japan, workers homes were intermingled with factories so that it was impossible to find a target that was exclusively military.  Finally, Truman stipulated it should not be a city of traditional cultural significance to Japan, such as Kyoto.  Truman did not seek to destroy Japanese culture or people; the goal was to destroy Japan’s ability to make war.

So, on the morning of August 6, 1945, the American B-29 bomber, the Enola Gay , dropped the world’s first atom bomb over the city of Hiroshima.  

What Happened in Japan That Day

The temperature near the blast site reached 5,400 degrees Fahrenheit.  The sky seemed to explode.  Birds ignited in midair; asphalt boiled.  People over two miles away burst into crumbling cinders.  Others with raw skin hanging in flaps around their hips leaped shrieking into waterways to escape the heat.  Men without feet stumbled about on the charred stumps of their ankles.  Women without jaws screamed incoherently for help.  Bodies described as "boiled octopuses" littered the destroyed streets.  Children, tongues swollen with thirst, pushed floating corpses aside to soothe their scalded throats with bloody river water.

One eyewitness at Hiroshima recalled, “I climbed Hikiyama Hill and looked down. I saw that Hiroshima had disappeared.... I was shocked by the sight.... Of course I saw many dreadful scenes after that — but that experience, looking down and finding nothing left of Hiroshima — was so shocking that I simply can't express what I felt.... Hiroshima didn't exist — that was mainly what I saw — Hiroshima just didn't exist.”

Approximately 80,000 people were killed as a direct result of the blast, and another 35,000 were injured.  At least another 60,000 would be dead by the end of the year from the effects of the atomic fallout.  

What Happened in America That Day

The President released a press release, which read in part, “Sixteen hours ago an American airplane dropped one bomb on Hiroshima and destroyed its usefulness to the enemy. ….  If they do not now accept our terms they may expect a rain of ruin from the air, the like of which has never been seen on this earth.”

A 21-year-old American second lieutenant recalled, “When the bombs dropped and news began to circulate that [the invasion of Japan] would not, after all, take place, that we would not be obliged to run up the beaches near Tokyo assault-firing while being mortared and shelled, for all the fake manliness of our facades we cried with relief and joy.  We were going to live.  We were going to grow up to adulthood after all.”

One week later, on August 14, 1945, after the second atomic bomb was dropped on Nagasaki, the Japanese surrendered.  World War II, the deadliest conflict in human history, with between 50 and 85 million fatalities, was finally over. 

What Did Harry S Truman Have to Say About His Decision to Use the Atomic Bomb?

At the time, the president seemed conflicted over his decision.  The day after the Hiroshima bomb was dropped, Truman received a telegram from Senator Richard B. Russell of Georgia, encouraging the president to use as many atomic bombs as possible on Japan, claiming the American people believed “that we should continue to strike the Japanese until they are brought groveling to their knees.”  Truman responded, “I know that Japan is a terribly cruel and uncivilized nation in warfare but I can't bring myself to believe that because they are beasts, we should ourselves act in that same manner.  For myself I certainly regret the necessity of wiping out whole populations because of the ‘pigheadedness’ of the leaders of a nation, and, for your information, I am not going to do it unless absolutely necessary.”

On August 9, the day the Nagasaki bomb was dropped, Truman received a telegram from Samuel McCrea Cavert, a Protestant clergyman, who pleaded with the president to stop the bombing “before any further devastation by atomic bomb is visited upon her [Japan’s] people.”  Two days later, Truman replied, “The only language they seem to understand is the one we have been using to bombard them.  When you have to deal with a beast you have to treat him as a beast.”

Looking back, President Truman never shirked personal responsibility for his decision, but neither did he apologize.  He asserted that he would not use the bomb in later conflicts, such as Korea.  Nevertheless, given the same circumstances and choices that confronted him in Japan in 1945, he said he would do exactly the same thing.

It was heavy burden to bear.  Speaking of himself as president, Truman said, “And he alone, in all the world, must say Yes or No to that awesome, ultimate question, ‘Shall we drop the bomb on a living target?’”  Every president since Harry Truman has had that power.  None has exercised it.

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Harry S Truman National Historic Site , Manhattan Project National Historical Park

Last updated: January 11, 2023

National Museum of Nuclear Science & History

Debate over the Bomb

• Bombings of Hiroshima and Nagasaki

One of the greatest controversies to come out of World War II was whether the atomic bomb was necessary to bring about the war’s end. Supporters of the bombings generally believe that they prevented an invasion of the Japanese mainland, saving more lives than they took by doing so. Opponents contend, among other arguments, that the bombings were unnecessary to win the war or that they constituted a war crime or genocide. Whether the atomic bombings truly forced the Japanese surrender, and whether projected casualty rates for the Japanese invasion were accurate, have been controversial issues for historians to tackle.

After the War

In the initial days following the Japanese surrender, the United States public overwhelmingly supported the use of atomic bombs on Hiroshima and Nagasaki. A Gallup poll taken in August 1945 found that 85 percent of Americans supported the bombings, 10 percent were opposed to them, and 5 percent had no opinion. Initial critics of the bombings were largely pacifists, a number of nuclear scientists, and some religious leaders and political commentators.

This initial support decreased as reports came in about the magnitude of destruction on Japan. John Hersey’s magazine-length article Hiroshima , which profiled six survivors of the bombing, appeared in the New Yorker one year after the bombing in August 1946, giving the American public a new picture of the human impact of the bomb and bringing a groundswell of negative opinion. As the specter of nuclear war grew in the 1950s, undercurrents of sentiment against the bombings increased, although a majority of Americans continued to support them.  

Traditionalists vs. Revisionists

In the decades since World War II, historians have engaged in an often vitriolic debate over the decision to use the atomic bombs. “Traditionalists” have maintained that the bombs were necessary in order to save American lives and prevent an invasion that might have cost many more lives than the bombs took. They frequently argue that President Truman decided to use the bombs in order to bring the war to a speedy conclusion, and that the bombs were essential to forcing Japan to surrender.

“Revisionist” scholars generally posit that the bombs were unnecessary. Among other claims, they suggest that Japan was ready to surrender and that the use of the bombs could have been avoided if the United States had guaranteed that Emperor Hirohito could remain on his throne. They also argue that the Soviet invasion of Manchuria on August 8-9, 1945, rather than the use of the atomic bombs, was decisive in precipitating Japan’s surrender.

For more information on the dispute over the bombings of Hiroshima and Nagasaki, see AHF’s annotated bibliography .  

The Enola Gay Controversy and Public Opinion Today

In 1995, the director of the Smithsonian National Air and Space Museum resigned after veterans’ organizations, conservatives, and even Congressmen protested a planned exhibit of the Enola Gay on the 50th anniversary of the end of World War II. Opponents had claimed that the exhibit was too sympathetic to Japan and too critical of American actions, and that it lacked information about Japanese wartime atrocities in China and the Pacific. The exhibit was eventually canceled , although the plane’s fuselage was still shown in the museum.

The topic of the bombings remains a contentious source of debate for historians and the public today. An August 2009 poll by Quinnipiac University found that 61 percent of Americans supported the bombing, with 22 percent opposed and 16 percent undecided. The poll found a significant gap in opinion based on respondents’ ages: 73 percent of those polled over 55 agreed with the bombing, while only 50 percent of those under 34 supported it.

In 2015, a Pew Research Center survey found that 56 percent of Americans believe that the bombings were justified. In Japan, only 14% agree the bombs were justified. Among Americans, the generation gap remains pronounced: 70% of respondents over the age of 65, but only 47% of those aged 18-29, agree that the bombings were justified.

On May 27, 2016, President Obama became the first sitting U.S. president to visit Hiroshima and renewed his call for a world without nuclear weapons. The debate over what historian Sam Walker calls “in terms of longevity and in terms of bitterness, the most controversial issue in American history” will likely continue for years to come.

• Debate over the Bomb: An Annotated Bibliography
• AHF interview with historian Sam Walker , author of Prompt and Utter Destruction: Truman and the Use of Atomic Bombs Against Japan .

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Atomic Bomb History

By: History.com Editors

Updated: November 9, 2022 | Original: September 6, 2017

The atomic bomb and nuclear bombs are powerful weapons that use nuclear reactions as their source of explosive energy. Scientists first developed nuclear weapons technology during World War II. Atomic bombs have been used only twice in war—both times by the United States against Japan at the end of World War II, in Hiroshima and Nagasaki. A period of nuclear proliferation followed that war, and during the Cold War, the United States and the Soviet Union vied for supremacy in a global nuclear arms race.

Nuclear Bombs and Hydrogen Bombs

A discovery by nuclear physicists in a laboratory in Berlin, Germany, in 1938 made the first atomic bomb possible, after Otto Hahn, Lise Meitner and Fritz Strassman discovered nuclear fission.

In nuclear fission, the nucleus of an atom of radioactive material splits into two or more smaller nuclei, which causes a sudden, powerful release of energy. The discovery of nuclear fission opened up the possibility of nuclear technologies, including weapons.

Atomic bombs get their energy from fission reactions. Thermonuclear weapons, or hydrogen bombs, rely on a combination of nuclear fission and nuclear fusion. Nuclear fusion is another type of reaction in which two lighter atoms combine to release energy.

Manhattan Project

On December 28, 1942, President Franklin D. Roosevelt authorized the formation of the Manhattan Project to bring together various scientists and military officials working on nuclear research.

The Manhattan Project was the code name for the American-led effort to develop a functional atomic bomb during World War II . The project was started in response to fears that German scientists had been working on a weapon using nuclear technology since the 1930s.

Who Invented the Atomic Bomb?

Much of the work in the Manhattan Project was performed in Los Alamos, New Mexico , under the direction of theoretical physicist J. Robert Oppenheimer , the “ father of the atomic bomb .”

On July 16, 1945, in a remote desert location near Alamogordo, New Mexico , the first atomic bomb was successfully detonated—the Trinity Test . It created an enormous mushroom cloud some 40,000 feet high and ushered in the Atomic Age.

Hiroshima And Nagasaki Bombings

Scientists at Los Alamos had developed two distinct types of atomic bombs by 1945—a uranium-based design called “the Little Boy” and a plutonium-based weapon called “the Fat Man.” (Uranium and plutonium are both radioactive elements.)

While the war in Europe had ended in April, fighting in the Pacific continued between Japanese forces and U.S. troops. In late July, President Harry Truman called for Japan’s surrender with the Potsdam Declaration . The declaration promised “prompt and utter destruction” if Japan did not surrender.

On August 6, 1945, the United States dropped its first atomic bomb from a B-29 bomber plane called the Enola Gay over the city of Hiroshima , Japan. The “Little Boy” exploded with about 13 kilotons of force, leveling five square miles of the city and killing 80,000 people instantly. Tens of thousands more would later die from radiation exposure.

When the Japanese did not immediately surrender, the United States dropped a second atomic bomb three days later on the city of Nagasaki . The “Fat Man” killed an estimated 40,000 people on impact.

Nagasaki had not been the primary target for the second bomb. American bombers initially had targeted the city of Kokura, where Japan had one of its largest munitions plants, but smoke from firebombing raids obscured the sky over Kokura. American planes then turned toward their secondary target, Nagasaki.

Citing the devastating power of “a new and most cruel bomb,” Japanese Emperor Hirohito announced his country’s surrender on August 15—a day that became known as ‘ V-J Day ’—ending World War II.

The Cold War

The United States was the only country with nuclear weaponry in the years immediately following World War II. The Soviet Union initially lacked the knowledge and raw materials to build nuclear warheads.

Within just a few years, however, the U.S.S.R. had obtained—through a network of spies engaging in international espionage—blueprints of a fission-style bomb and discovered regional sources of uranium in Eastern Europe. On August 29, 1949, the Soviets tested their first nuclear bomb.

The United States responded by launching a program in 1950 to develop more advanced thermonuclear weapons. The Cold War arms race had begun, and nuclear testing and research became high-profile goals for several countries, especially the United States and the Soviet Union.

Cuban Missile Crisis

Over the next few decades, each world superpower would stockpile tens of thousands of nuclear warheads. Other countries, including Great Britain, France, and China, developed nuclear weapons during this time, too.

To many observers, the world appeared on the brink of nuclear war in October of 1962. The Soviet Union had installed nuclear-armed missiles on Cuba, just 90 miles from U.S. shores. This resulted in a 13-day military and political standoff known as the Cuban Missile Crisis .

President John F. Kennedy enacted a naval blockade around Cuba and made it clear the United States was prepared to use military force if necessary to neutralize the perceived threat.

Disaster was avoided when the United States agreed to an offer made by Soviet leader Nikita Khrushchev to remove the Cuban missiles in exchange for the United States promising not to invade Cuba.

Three Mile Island

Many Americans became concerned about the health and environmental effects of nuclear fallout—the radiation left in the environment after a nuclear blast—in the wake of World War II and after extensive nuclear weapons testing in the Pacific during the 1940s and 1950s.

The antinuclear movement emerged as a social movement in 1961 at the height of the Cold War. During Women Strike for Peace demonstrations on November 1, 1961 co-organized by activist Bella Abzug , roughly 50,000 women marched in 60 cities in the United States to demonstrate against nuclear weapons.

The antinuclear movement captured national attention again in the 1970s and 1980s with high profile protests against nuclear reactors after the Three Mile Island accident—a nuclear meltdown at a Pennsylvania power plant in 1979.

In 1982, a million people marched in New York City protesting nuclear weapons and urging an end to the Cold War nuclear arms race. It was one of the largest political protests in United States history.

Nuclear Non-Proliferation Treaty (NPT)

The United States and Soviet Union took the lead in negotiating an international agreement to halt the further spread of nuclear weapons in 1968.

The Treaty on the Non-Proliferation of Nuclear Weapons (also called the Non-Proliferation Treaty or NPT) went into effect in 1970. It separated the world’s countries into two groups—nuclear weapons states and non-nuclear weapons states.

Nuclear weapons states included the five countries that were known to possess nuclear weapons at the time—the United States, the U.S.S.R., Great Britain, France and China.

According to the treaty, nuclear weapons states agreed not to use nuclear weapons or help non-nuclear states acquire nuclear weapons. They also agreed to gradually reduce their stockpiles of nuclear weapons with the eventual goal of total disarmament. Non-nuclear weapons states agreed not to acquire or develop nuclear weapons.

When the Soviet Union collapsed in the early 1990s, there were still thousands of nuclear weapons scattered across Eastern Europe and Central Asia. Many of the weapons were located in Belarus, Kazakhstan and Ukraine. These weapons were deactivated and returned to Russia.

Illegal Nuclear Weapon States

Some countries wanted the option of developing their own nuclear weapons arsenal and never signed the NPT. India was the first country outside of the NPT to test a nuclear weapon in 1974.

Other non-signatories to the NTP include: Pakistan, Israel and South Sudan. Pakistan has a known nuclear weapons program. Israel is widely believed to possess nuclear weapons, though has never officially confirmed or denied the existence of a nuclear weapons program. South Sudan is not known or believed to possess nuclear weapons.

North Korea

North Korea initially signed the NPT treaty, but announced its withdrawal from the agreement in 2003. Since 2006, North Korea has openly tested nuclear weapons, drawing sanctions from various nations and international bodies.

North Korea tested two long-range intercontinental ballistic missiles in 2017—one reportedly capable of reaching the United States mainland. In September 2017, North Korea claimed it had tested a hydrogen bomb that could fit on top an intercontinental ballistic missile.

Iran, while a signatory of the NPT, has said it has the capability to initiate production of nuclear weapons at short notice.

Pioneering Nuclear Science: The Discovery of Nuclear Fission. International Atomic Energy Agency . The Development and Proliferation of Nuclear Weapons. NobelPrize.org . Here are the facts about North Korea’s nuclear test. NPR .

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• Reasons Against Dropping the Atomic Bomb

Note: This section is intended as an objective overview of reasons against dropping the atomic bomb. For the other side of the issue, go here.

Reasons Against Dropping the Atomic Bomb — Argument 1: The Bomb Was Made For Defense Only

The origins of the Manhattan Project go back to 1939, when Hungarian-born physicist Leo Szilard, who had moved to the U.S. in 1938 to conduct research at Columbia University, became convinced of the feasibility of using nuclear chain reactions to create new, powerful bombs. German scientists had just conducted a successful nuclear fission experiment, and based on those results, Szilard was able to demonstrate that uranium was capable of producing a nuclear chain reaction.  Szilard noted that Germany had stopped the exportation of uranium from Czechoslovakian mines which they had taken over in 1938.

He feared that Germany was trying to build an atomic bomb, while the United States was sitting idle.  Although WWII had not yet started, Germany was clearly a threat, and if the Germans had a monopoly on the atomic bomb, it could be deployed against anyone, including the United States, without warning. Szilard worked with Albert Einstein, whose celebrity gave him access to the president, to produce a letter informing Roosevelt of the situation.  Their warning eventually resulted in the Manhattan Project.   As far as reasons against dropping the atomic bomb, bomb opponents argue that the atomic bomb was built as a defensive weapon, not an offensive one.  It was intended to be a deterrent, to make Germany or any other enemy think twice before using such a weapon against the United States.  To bolster their argument, these critics point out that ever since WWII, the weapon has been used only as a deterrent.

From 1949-to 1991, the Cold War was waged under the shadow of Mutually Assured Destruction (MAD), and even though the United States fought major wars in Korea (while Truman was still in office), Vietnam, Iraq, and Afghanistan, nuclear weapons were never again deployed. In other words, not using them in those wars has been an admission that they should never have been used offensively in the first place.

Reasons Against Dropping the Atomic Bomb — Argument 2: Use of the Bomb was Illegal

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Another one of the reasons against dropping the atomic bomb was the League of Nations. On September 39, 1938, the League of Nations, “under the recognized principles of international law,” issued a unanimous resolution outlawing the intentional bombing of civilian populations, with special emphasis against bombing military objectives from the air.  The League warned, “Any attack on legitimate military objectives must be carried out in such a way that civilian populations in the neighborhood are not bombed through negligence.”  Significantly, the resolution also reaffirmed that “the use of chemical or bacterial methods in the conduct of war is contrary to international law.”  In other words, a special category of illegal weapons had been recognized, a category today called Weapons of Mass Destruction (WMD).

However, bomb supporters point out that since the United States was not a member of the League of Nations; its laws did not apply.  And anyway, the League had been disbanded in 1939, long before the atomic bomb was used.  Additionally, the law did not specifically outlaw nuclear weapons.  To that counter-argument, bomb opponents reply that since America presents itself to the world as a model for human rights, the U.S. should aspire to at least meet the basic code of conduct agreed to by the rest of the civilized world. They also point out that nuclear weapons were not specifically outlawed because they did not exist, but as a weapon of mass destruction, they most certainly would have been.

Reasons Against Dropping the Atomic Bomb — Argument 3: Use of the Atomic Bombs Was Racially Motivated

Opponents of President Truman’s decision to use the atomic bomb argue that racism played an important role in the decision; that had the bomb been ready in time it never would have been used against Germany. All of America’s enemies were stereotyped and caricatured in home front propaganda, but there was a clear difference in the nature of that propaganda.  Although there were crude references to Germans as “krauts,” and Italians as “Tonies” or “spaghettis,” the vast majority of ridicule was directed at their political leadership.  Hitler, Nazis, and Italy’s Mussolini were routinely caricatured, but the German and Italian people weren’t.

By contrast, anti-Japanese racism in American society targeted the Japanese as a race of people and demonstrated a level of hatred comparable with Nazi anti-Jewish propaganda.  The Japanese were universally caricatured as having huge buck teeth, massive fangs dripping with saliva, and monstrous thick glasses through which they leered with squinty eyes. They were further dehumanized as being snakes, cockroaches, and rats, and their entire culture was mocked, including language, customs, and religious beliefs. Anti-Japanese imagery was everywhere—in Bugs Bunny cartoons, popular music, postcards, children’s toys, magazine advertisements, and in a wide array of novelty items ranging from ashtrays to “Jap Hunting License” buttons.  Even Tarzan, in one of the last novels written by his creator Edgar Rice Burroughs, spent time in the Pacific hunting and killing Japs.  Numerous songs advocated killing all Japanese.  The popular novelty hit, “Remember Pearl Harbor” by Carson Robison, for example, urges Americans to “wipe the Jap from the map.”  It continues:

Remember how we used to call them our “little brown brothers?” What a laugh that turned out to be Well, we can all thank God that we’re not related To that yellow scum of the sea They talked of peace, and of friendship We found out just what all that talk was worth All right, they’ve asked for it, and now they’re going to get it We’ll blow every one of them right off of the face of the Earth

Americans didn’t like Mussolini, Hitler, and Nazis, but many hated the Japanese race.  The official magazine of the US Marine Corps, The Leatherneck, in May 1945 called the Japanese a “pestilence,” and called for “a giant task of extermination.” The American historian Steven Ambrose, a child during the war, has said that because of the propaganda, he grew up thinking that the only good Jap was a dead Jap.  That hatred began with Pearl Harbor and increased when news broke of the Bataan Death March, and with each act of defiance against America’s “island-hopping” campaign.  Killing became too easy, and the dehumanizing of the enemy commonplace. Some American soldiers in the Pacific sent home to their girlfriends the skulls of Japanese soldiers, to be displayed on their desks at work. American soldiers did not send home Nazi skulls as trophies or sweetheart gifts. In 1944 a US Congressman presented President Roosevelt with a letter-opener purportedly made from the arm bone of a Japanese soldier.

American racism led to a failure to distinguish between the Japanese government, dominated by hard-line militarists, and the Japanese civilian who was caught up in their government’s war.  Racists viewed all Japanese as threats not because of their political education, but because of their genetics. As further evidence, bomb opponents point to US policy toward the Japanese-Americans living in California at the time.  They were rounded up, denied their basic liberties under the Constitution (even though many of them were American citizens), and sent to isolated camps in the deserts, surrounded by barbed wire, until the war’s end.

Nothing on this scale was done to the Germans during WWII, or even during the First World War, when there were millions of German and Austrian immigrants and their children living in the United States. In May 1944 Life magazine reported on the hardships of George Yamamoto, a Japanese-American who had immigrated to the US in 1920 at the age of 17 to work on his family’s farm. In 1942 Mr. Yamamoto worked at a fish market, ran a sporting goods store, and was a solid member of his community, along with his wife and children.

They were interned, but Mr. Yamamoto applied for a relocation program, was cleared by the US government as loyal and trustworthy, and was packed off to Delaware to find work. He was run out of town before he could even start, and was relocated to New Jersey, where he was to work on a farm owned by Eddie Kowalick. But the citizens of New Jersey were no more accommodating. They feared an influx of Jap workers and didn’t want their kids sitting next to “yellow” children in school. A petition to evict Yamamoto was circulated, there were multiple threats of violence against him, and one of Mr. Kowalick’s barns was burned to the ground. After threats were made against the life of Mr. Kowalick’s baby, he felt he had no choice but to ask Mr. Yamamoto to move on. Three weeks after Life printed this story, they printed letters written in response.  Most of those selected by the editorial staff for publication were supportive of Mr. Yamamoto and expressed embarrassment at the ignorance of some Americans. But the magazine also published this letter, written by William M. Hinds of Birmingham, Alabama:

Sirs, there are many of us who believe that the deceit, treachery, and bestiality inherent in the Japanese we are fighting in the Pacific are traits not automatically removed from members of the race merely by accident of birth in the US. There are many of us who believe, quite sincerely and simply, that Japanese immigrants to the US and their American-born children will deliberately live an impeccable American life while awaiting an opportunity to perpetrate a Pearl Harbor of their own dimensions. Cheers for the public-spirited citizens of New Jersey who ran Mr. Yamamoto away. 

While it’s easy to see that extreme racism toward the Japanese existed, it’s much more difficult to assess the role racism may have played in President Truman’s decision. However, there are a few instances in the historical record where the President does refer to the Japanese in questionable terms.  In his July 25, 1945 diary entry, as Truman is writing about the bomb, he refers to the “Japs” as “savages, ruthless, merciless and fanatic.” On August 11, after both Hiroshima and Nagasaki had been devastated, an American clergyman named Samuel McCrea Cavert wrote the President urging him to give the Japanese time to surrender before using any more atomic bombs.  Truman replied, “When you have to deal with a beast you have to treat him as a beast.” Whether these comments are racist about the Japanese people or only express the President’s opinion about the Japanese military is a matter of interpretation.

Reasons Against Dropping the Atomic Bomb — Argument 4: There Were Alternatives

Supporters of President Truman’s decision to use atomic weapons against Japan tend to paint the decision as a difficult choice between two stark options—it was either American boys or the bomb.  Opponents of the bomb are adamant that there were other options available to the President, which at the very least should have been tried before resorting to the bomb.

Alternative 1: A Demonstration of the bomb

One alternative might have been to arrange a demonstration of the bomb.  Although the U.S. and Japan had no diplomatic relations after Pearl Harbor, a demonstration might have been arranged discretely through some back channel, perhaps through the Russians.  It was already known in Washington that the Japanese had reached out to the Russians earlier to try to arrange some form of mediation with the U.S.  After the war, the United States did conduct numerous atomic bomb tests on small volcanic atolls in the Pacific.  Such a site could have been prepared in 1945. If representatives of the Japanese government, military, and scientific community could have seen the bomb, it might have been enough to convince them of the foolishness of continued resistance.  If not, at least the U.S. could say that they had tried, thereby maintaining the moral high ground.

Bomb supporters make several counter-points.  Although the test in the New Mexican desert had been successful, the technology was still new.  What if the demonstration bomb didn’t work? The United States would have looked weak and foolish.  A failed demonstration might even serve to increase Japanese resolve.  Additionally, the U.S. only had two bombs left after Los Alamos.  If the demonstration failed to convince the Japanese to surrender, only one bomb would remain.  Others would presumably be produced later, but there was no guarantee of that. One bomb, as it turned out, was not enough to force surrender.

A third counter-point is that a demonstration would eliminate the element of surprise, and the Japanese might use American POWs as human shields.  The four cities on the target list had not been bombed with conventional weapons so that they might serve as accurate test subjects for the destructive powers of the atomic bomb.   The Japanese would surely deduce American strategy and might move Americans to those target cities.  Finally, bomb supporters counter-argue that it was the opinion of Robert Oppenheimer and other scientists on the Interim Committee that a demonstration wouldn’t convince the Japanese to surrender.  “We can propose no technical demonstration likely to bring an end to the war,” they wrote. “We see no acceptable alternative to direct military use.”

Alternative 2: Wait For the Russians Military analysts working for the Joint Intelligence Committee (JIC) in 1945 believed that two things must happen for the Japanese leadership to surrender. There had to be acceptance of the inevitability of defeat; and a clarification from the Americans that “unconditional surrender” did not mean national annihilation.  The JIC believed as early as April 11, 1945, that a Soviet declaration of war on Japan would satisfy the first necessity:

By the autumn of 1945, we believe that the vast majority of Japanese will realize the inevitability of absolute defeat regardless of whether the U.S.S.R. has actually entered the war against Japan. If at any time the U.S.S.R. should enter the war, all Japanese will realize that absolute defeat is inevitable.

A Strategy and Policy Group within the War Department arrived at the same conclusion in June, and their work was discussed between General Marshall and Secretary Stimson.  The Americans also knew what the Japanese were thinking on this subject.  Having long-broken the Japanese diplomatic code, the United States eavesdropped on conversations between the Japanese Foreign Minister in Tokyo, and the Japanese ambassador to the Soviet Union in Moscow. In a cable sent on June 4, the Foreign Minister wrote:

It is a matter of utmost urgency that we should not only prevent Russia from entering the war but should also induce her to adopt a favorable attitude toward Japan.  I would therefore like you to miss no favorable opportunity to talk to the Soviet leaders.

The ambassador cabled back that there wasn’t much reason to hope, and that he had received reports of substantial Soviet troop and supply movements heading the east.  He continued:

If Russia by some chance should suddenly decide to take advantage of our weakness and intervene against us with the force of arms, we would be in a completely hopeless situation.  It is clear as day that the Imperial Army in Manchukuo would be completely unable to oppose the Red Army which has just won a great victory and is superior to us on all points.

The Japanese had reason to fear.  In the Second World War, the United States and the Soviet Union put aside their ideological differences to form an alliance against Nazi Germany.  It was an uneasy alliance; Joseph Stalin believed that the Americans and British had purposely delayed opening a second front in Europe (D-Day—June 6, 1944) so that the Russians would bear the brunt of defeating the Nazis.  Nevertheless, in a secret meeting between President Roosevelt and Stalin at Yalta, the Soviet leader had promised that three months after the end of the European campaign he would declare war on Japan and move against Japanese forces in China.

In July, when President Truman traveled to Germany to meet his Allied leaders for the first time, pinning down Stalin on the exact date was at the top of his agenda.  When Truman and Stalin met on the 17th, the Soviet leader confirmed they would declare war on Japan on August 15.  Later that night, Truman wrote in the diary, “Most of the big points are settled. He’ll be in the Jap War on August 15th. Fini Japs when that comes about” (meaning, they’ll be finished). Some bomb supporters point out that according to post-war interviews of Japanese leaders, none of the high-ranking officials were of a mind that a Soviet attack alone would have convinced them to surrender.  However, this is irrelevant if Truman believed it would, and if intelligence information at the time suggested it would.

To summarize, by July 17 the American military, the President, and at least some Japanese all were of a mind that Soviet intervention in the war would prove decisive.  And, a date for this intervention had been set.  Bomb opponents thus question why the United States used atomic bombs on August 6 and 9, when they knew the Russians were coming a week later, and when Operation Torch wasn’t scheduled for months.  Why not wait?  Opponents believe they know the answer to that question, discussed below as argument #5.

Alternative 3: Let the Japanese Keep Their Emperor The third and perhaps most important alternative to both the bomb and the land invasion was to modify the demand for unconditional surrender and allow the Japanese to keep their emperor.  Of course, he would have to be demoted to a powerless figurehead (much like the Royal Family in Great Britain), but it was possible that this one condition alone might have been enough to satisfy the American War Department’s conclusion that it was necessary to convince the Japanese that they would not be “annihilated” if they surrendered.  The American government clearly understood that if they harmed the emperor, whom the Japanese revered as a god, the Japanese would resist forever.  And the key to this argument lies in the fact that the American government already planned on letting the emperor stay.  All they had to do was find a way to hint at their intentions loud enough for the Japanese to hear.  On June 13, in a memorandum to President Truman from Acting Secretary of State Joseph Grew (former American ambassador to Japan), Grew wrote:

Every evidence, without exception, that we are able to obtain of the views of the Japanese with regard to the institution of the throne, indicates that the non-molestation of the person of the present emperor and the preservation of the institution of the throne comprises irreducible Japanese terms…They are prepared for prolonged resistance if it be the intention of the United Nations to try the present emperor as a war criminal or to abolish the imperial institution…Failure on our part to clarify our intentions in this regard..will ensure prolongation of the war and cost a large number of human lives.

Secretary of War Stimson also argued that American intentions regarding the emperor should be made clearer.  General Marshall referred to this as “giving definition to unconditional surrender” (ultimately resulting in the Potsdam Declaration).  On the Interim Committee, he was joined in this point by Undersecretary of the Navy Ralph A. Bard.  In a June 27 memo to Stimson, Bard wrote:

During recent weeks I have also had the feeling very definitely that the Japanese government may be searching for some opportunity which they could use as a medium of surrender. Following the three-power conference emissaries from this country could contact representatives from Japan somewhere on the China Coast and make representations with regard to Russia’s position and at the same time give them some information regarding the proposed use of atomic power, together with whatever assurances the President might care to make with regard to the Emperor of Japan and the treatment of the Japanese nation following unconditional surrender. It seems quite possible to me that this presents the opportunity which the Japanese are looking for.

But by the time Stimson pushed on this issue, the President was very much under the influence of former Senator James Byrnes, who had become Truman’s personal advisor and was soon to be named the new Secretary of State.  Byrnes argued that the President would be crucified politically by the Republicans for “making a deal” with the Japanese.  Byrnes won the argument and eliminated crucial language in the Potsdam Declaration about the Emperor, Truman gave a less-than-convincing excuse that Congress didn’t seem interested in modifying unconditional surrender, and the Japanese were left in the dark with regards to American intentions toward the emperor.

Although there was certainly no guarantee that taking this action would bring about a Japanese surrender, bomb opponents argue that it was at least worth a try (although bomb supporters counter-argue that doing so could have been interpreted as a weakness by the Japanese military leadership and could actually have emboldened the Japanese to fight on).  Instead, the Japanese ignored the Potsdam Declaration, the atomic bombs were dropped, the Japanese surrendered, and the Americans, as planned, allowed the emperor to stay on the throne (where he remained until his death in 1989).  This is the one area where Secretary of War Stimson had regrets.  His biographer later wrote, “Only on the question of the Emperor did Stimson take, in 1945, a conciliatory view; only on this question did he later believe that history might find that the United States, by its delay in stating its position, had prolonged the war.” Seems like a pretty fair point among the reasons against dropping the atomic bomb.

Alternative 4: Continue Conventional Bombing Some military analysts were convinced in the summer of 1945 that Japan very near surrendered, that the pounding they were taking from conventional weapons would soon convince the Japanese cabinet that further resistance was futile.  That position was bolstered when, after the war, Secretary of War Stimson commissioned aboard to perform a detailed investigation into the effectiveness of Allied bombings during the war.  They subsequently interrogated 700 Japanese military, government, and industry officials, and they recovered and translated documents related to the war effort.  Their report, the Strategic Bombing Survey, makes the obvious observation that Japan might have surrendered earlier if they had had a different government. That was seen as one of the better reasons against dropping the atomic bomb. But it goes on to express a more startling opinion:

Nevertheless, it seems clear that, even without the atomic bombing attacks, air supremacy over Japan could have exerted sufficient pressure to bring about unconditional surrender and obviate the need for invasion…Based on a detailed investigation of all the facts, and supported by the testimony of the surviving Japanese leaders involved, it is the Survey’s opinion that certainly prior to 31 December 1945, and in all probability prior to 1 November 1945, Japan would have surrendered even if the atomic bombs had not been dropped, even if Russia had not entered the war, and even if no invasion had been planned or contemplated.

Bomb supporters are extremely critical of this alternative. Specifically, they charge that information counter to the Survey’s conclusion was left out of the report, and that inter-service wrangling resulted in the Air Force over exaggerating its role in the war so as to secure a large post-war budget. They also point out that even if the Survey’s evidence and conclusions were accurate, it is illogical to criticize the Truman administration for not pursuing an alternative to the bomb that was based on information obtained only after the war was over.

The President had to make his choice based on information known to him at the time.  More importantly, bomb supporters are critical of this alternative because despite the overwhelming naval and air superiority enjoyed by US forces at the end of the summer of 1945; those forces were still suffering significant losses. Kamikazes were still attacking American vessels.  The USS Indianapolis, after delivering the Hiroshima bomb materials to Tinian island in the Marianas, was sunk on July 30.  Of 1,196 crewmen aboard, approximately 300 went down with the ship. Of the remaining 900 men who went into the water, only 317 survivors were picked up when the wreckage was discovered four days later. The rest died from exposure, dehydration, and shark attacks. It was the single greatest loss of life in the entire history of the US Navy. Meanwhile, Allied casualties were still averaging about 7,000 per week. As war veteran and writer Paul Fussell later pointed out, “Two weeks more means 14,000 more killed and wounded, three weeks more, 21,000.  Those weeks mean the world if you’re one of those thousands or related to one of them.”  And Allied losses continued even after the atomic bombings. Between August 9 and the actual surrender on the 15th, eight American POWs were executed via beheadings, the US submarine Bonefish was sunk with the loss of its entire crew, and the destroyer Callagan and the USS Underhill were lost.

Reasons Against Dropping the Atomic Bomb – Argument #5: Use of the bomb was more to scare Russia than to defeat Japan.

As discussed above, bomb opponents question why the United States used atomic bombs on August 6 and 9, when they knew the Russians were going to declare war on Japan a week later, and when Operation Torch wasn’t scheduled for months.  Why not wait?  Bomb opponents believe that the American government did not wait for the Russians because they were already thinking about the post-war world and how they could best limit Soviet gains when they redrew the map of Europe. They believed the shock-and-awe effect of using the atomic bomb against Japan would make the Soviet Union more manageable in post-war negotiations. (This argument had been made most consistently by historian Gar Alperovitz). There was certainly reason to be concerned about the Soviet Union.  When Germany collapsed, the Russians had made huge advances.  Russian troops moved into Hungary and Rumania and showed no inclination to leave there or the Balkans. But was it an acceptable trade-off to annihilate several hundred thousand civilians just so the Russians wouldn’t be able to get in on the kill of Japan, and so the U.S. might have the upper hand in the post-war world? Bomb opponents are abhorred by the moral implications.

In the spring of 1945, as Germany surrendered, some of the scientists who had developed the new weapon as a Nazi deterrent started to have reservations about their invention. One was Leo Szilard, who had written the letter along with Einstein back in 1939 that had convinced Roosevelt to start the Manhattan Project.  In April 1945 Einstein wrote a letter of introduction for Szilard, who was able to get a meeting with Mrs. Roosevelt on May 8.  But then the President died.  When Szilard tried to get a meeting with Truman, he was intercepted by James Byrnes, who received him in his South Carolina home.  Szilard’s biggest concern was that the Soviet Union should be informed about the bomb ahead of time.  He was afraid that the shock of America using the bomb on Japan would NOT make the Soviets more manageable, but would instead spur them to develop their own atomic bomb as quickly as possible, possibly igniting an arms race that could eventually lead to a nuclear war.  But Szilard was talking to exactly the wrong person.

Byrnes told Szilard, “Russia might be more manageable if impressed by American military might, and that a demonstration of the bomb [on Japan] might impress Russia.”  Years later, Szilard wrote of the encounter, “I shared Byrnes’ concerns about Russia’s throwing her weight around in the post-war period, but I was completely flabbergasted by the assumption that rattling the bomb might make Russia more manageable.” He later mused, “How much better off the world might be had I been born in America and become influential in American politics, and had Byrnes been born in Hungary and studied physics.”

Having met with Szilard, Byrnes was even more firmly convinced of the rightness of his own views.  At the Interim Committee meetings, he cut off any debate about warning the Soviets, and Secretary of War Stimson gave in. When Stimson briefed Truman on June 6, he informed the President that the Interim Committee recommended he not tell their Soviet ally about the bomb, “Until the first bomb had been successfully laid on Japan.”  But Stimson wasn’t sure how they should handle the meeting with Stalin at Potsdam. Truman replied that he had purposefully delayed the meeting for as long as possible to give the Manhattan scientists more time.  Having been counseled by Byrnes, Truman was already thinking about how to handle the Russians.

According to historian Gar Alperovitz in the 1985 edition of his work, Atomic Diplomacy, when Truman was on his way to Potsdam, he was overheard by a White House Aide to have said during a discussion about the test bomb and what it meant to America’s relationship with the Soviet Union, “If it explodes, as I think it will, I’ll certainly have a hammer on those boys.” For decades now bomb opponents have cited this story as evidence of Truman’s true intentions.  However, a close look at the sources raises questions about Alperovitz’s methods. That story was first told by the White House Aide himself, Jonathan Daniels, in a book published in 1950.  Daniels says he had heard the story second-hand and he stated specifically that Truman had been referring to Japan. He only speculated that the President might also have had the Russians in mind.

While at Potsdam, Truman received a coded message confirming the success of the test bomb.  According to Winston Churchill, it completely changed Truman’s demeanor toward Stalin; made him more confident and bossy. Just before leaving Potsdam, Truman did feel obliged to say something to the Soviet leader.  He writes in his diary, “I casually mentioned to Stalin that we had a new weapon of unusual destructive force.” But Truman did not say it was an atomic bomb.  On his way back from Potsdam,Truman gave the order to use the new weapon (even though they had not yet issued the Potsdam Declaration).

But Leo Szilard wasn’t quite finished yet.  Having been dismissed by Byrnes, he wrote a petition to the President of the United States, in which he warned that unless handled properly, the bomb might ignite an arms race that could result in “devastation on an unimaginable scale.”  Dated July 17, the petition was co-signed by 69 Manhattan Project scientists.  President Truman did not see the petition until after the atomic bombs had been dropped.  It was intercepted and held back by General Leslie Groves, military head of the Manhattan Project and a key advisor to James Byrnes.

Reasons Against Dropping the Atomic Bomb — Argument #6: Truman Was Unprepared for Presidential Responsibility

Another criticism directed toward President Truman is that he simply wasn’t ready for the responsibility of being president; he didn’t understand the ramifications of his decisions, he delegated too much authority, and he was unduly influenced by James Byrnes. This has been looked at as one of the chief reasons against dropping the atomic bomb

Byrnes has been discussed in detail above, but a summary of the key moments where his influence was most critical is appropriate.  He intercepted Leo Szilard and made sure the President never heard his views.  He dominated the Interim Committee as Truman’s personal representative, where he stifled debate and pushed successfully for a recommendation to the President that the bomb be dropped without warning either the Russians or the Japanese.  Additionally, Truman allowed Byrnes to erase crucial language in the Potsdam Declaration.  The original draft specifically mentioned the bomb, and American intentions to allow the emperor to stay. The result was a final draft that threatened only vague “utter destruction,” and might have been interpreted as a threat to the emperor.  Without the specific language regarding the emperor, the Japanese were left with the promise that justice would be meted out to all war criminals.  Critics argue that Truman, who stood so small in FDR’s shoes, was too inexperienced to form his own opinions, and too weak to resist Byrne’s dominance.

The second criticism of Truman is that he did not keep enough personal control over this terrifying new weapon.  The military order to use the bomb, delivered before the Potsdam Declaration had been issued, is an open-ended order in which the Air Force had too much control. The aircraft group that included the Enola Gay was directed to deliver the first atomic bomb, weather-permitting, on any of the four target cities: Hiroshima, Kokura, Niigata, or Nagasaki, on or after August 3.  The order goes on to say, “Additional bombs will be delivered on the above targets as soon as made ready by the project staff. Further instructions will be issued concerning targets other than those listed above.” In other words, the Air Force had instructions to bomb any or all of these four cities whenever atomic bombs were ready.  If a dozen atomic bombs had been ready instead of only two, no further permission would have been required to use them.  In fact, it took an order from President Truman to stop any further bombing after Nagasaki had been hit.

At the very least, critics argue, Truman should have required permission to use the second bomb. Originally, the second target was not scheduled to be attacked until six days after Hiroshima.  But with bad weather in the forecast, and with the Russians suddenly declaring war on Japan after the Hiroshima bomb, General Groves moved up the date to make sure that the plutonium bomb was “field-tested” before the war could end (Hiroshima had been hit with a Uranium bomb).  Some critics have pointed out that three days was simply not enough time for the Japanese to even confirm what had happened in Hiroshima, which appeared to them to have simply blinked off the map.  Although the Japanese leadership suspected the bombing was atomic in nature, they sent scientists to Hiroshima to confirm these suspicions and they had not even returned with their findings when Nagasaki was hit.  There are some critics who support dropping the first bomb, but feel the second was completely unnecessary. Either way, critics of the dropping of “Fat Man” on Nagasaki blame Truman for a lack of leadership. So, the arguments can be split in that way and one could support the first dropping, but not the second. This was also among the more common reasons against dropping the atomic bomb.

Some critics question whether or not Truman really understood the weapon and the human consequence of his decision to use it. A lack of understanding also was among the decent reasons against dropping the atomic bomb. On July 25, Truman describes in his diary some of the details he had just received about the test bomb in Los Alamos. He then writes, “I have told the Sec. of War, Mr. Stimson, to use it so that military objectives and soldiers and sailors are the target and not women and children.”  On the 9th, the day Nagasaki was bombed, President Truman addressed the nation on radio.  He said, “The world will note that the first atomic bomb was dropped on Hiroshima, a military base. That was because we wished in this first attack to avoid, insofar as possible, the killing of civilians.”  Considering the nature of the weapon, the Interim Committee’s recommendation to use the bomb against “workers’ dwellings”, and that the center of the city was the aiming point for the bomb, these claims are jaw-dropping.

Either President Truman really did not understand the bomb, or he was covering his “posterity”.  Either way, critics argue, it does not reflect well on the President. If the former is true, evidence suggests Hiroshima and Nagasaki quickly educated the president.  On August 10, having received reports and photographs of the effects of the Hiroshima bomb, Truman ordered a halt to further atomic bombings. That night, Secretary of Commerce Henry Wallace recorded in his diary, “Truman said he had given orders to stop the atomic bombing. He said the thought of wiping out another 100,000 people was too horrible. He didn’t like the idea of killing, as he said, ‘all those kids’.”

Reasons Against Dropping the Atomic Bomb — Argument 7: The Atomic Bomb Was Inhumane

The logical conclusion to the list of arguments against the bomb is that use of such a weapon was simply inhumane.  Hundreds of thousands of civilians with no democratic rights to oppose their militarist government, including women and children, were vaporized, turned into charred blobs of carbon, horrifically burned, buried in rubble, speared by flying debris, and saturated with radiation.  Entire families, whole neighborhoods were simply wiped out.  The survivors faced radiation sickness, starvation, and crippling mutilations. Then there were the “hidden cracks,” the spiritual, emotional, and psychological damage.  Japanese outside of Hiroshima and Nagasaki, scared and ignorant about radiation sickness, treated bomb victims as if they had a communicable disease.  They were shunned and ostracized from Japanese society.  Some blamed themselves for various reasons—like a woman who convinced her parents to move to Hiroshima before the bomb was dropped, or those who were the only survivor of a family, or of an entire school. Others, unable to cope with trauma left untreated, committed suicide.  Radiation continued to haunt the survivors, bringing a lifetime of sickness, not the least of which was an increase in the rates of various cancers.

Birth defects for those pregnant at the time jumped significantly, and although the data on birth defects passed down through generations is inconclusive (Hiroshima and Nagasaki are ongoing laboratories of the long-term effects of radiation exposure), bomb survivors and their offspring continue to suffer anxiety about the possibilities.  It is impossible to do justice to this argument in a simple summary.  A few specific first-hand accounts could be repeated here, but they would be insufficient. To truly grasp the magnitude of the suffering caused by the use of atomic weaponry on human beings, one has to be immersed in the personal.  The cold statistics must give way to the human story.  For some Americans, that process began with the publication of John Hersey’s Hiroshima in 1946, and it continues today through such autobiographical accounts as Keiji Nakazawa’s epic manga series Barefoot Gen (all ten volumes of which were recently published in English by Last Gasp Press), and through stunning documentaries like HBO’s White Light, Black Rain(2007).

In 1945, not many Americans seemed to be thinking things through.  Those cold statistics and that war-time hatred made using the bomb easy to rationalize. Leo Szilard was one of those few when he worried that using it without any warning would hurt America’s moral standing in the world.  In the years that followed, some Americans who were intimately involved with the atomic bombs did start to think things through. Admiral Leahy, President Roosevelt’s Chief of Staff, wrote in his memoir:

It is my opinion that the use of this barbarous weapon at Hiroshima and Nagasaki was of no material assistance in our war against Japan. The Japanese were already defeated and ready to surrender… My own feeling was that in being the first to use it, we had adopted an ethical standard common to the barbarians of the Dark Ages. I was not taught to make wars in that fashion, and that wars cannot be won by destroying women and children.

Even some of those who participated in the mission had regrets.  Captain Robert A. Lewis, the co-pilot on the Enola Gay’s mission over Hiroshima, wrote in his log as the bomb exploded, “My God, what have we done?”  In 1955 he participated in an episode of the television show This is Your Life that featured a Hiroshima survivor.  Lewis donated money on behalf of his employer for operations to help remove the scar tissue of young Japanese women horribly disfigured by the bomb ten years earlier.

America supposedly places a high value on life.  To a significant portion of the country, protecting a fertilized human egg is so important; they are willing to base their vote on this one issue alone.  And humaneness extends to the animal world as well. People go to prison for being cruel to their pets.  In a society that places so much value on life, how can the immense death and suffering of non-combatants caused by the atomic bombs be justified?  Opponents of President Truman’s decision to use those weapons argue simply that it cannot.

So, there you have it. A compendium and anthology on all of the reasons against dropping the atomic bomb.

Sources Used and Recommended

This article is part of our larger educational resource on World War Two. For a comprehensive list of World War 2 facts, including the primary actors in the war, causes, a comprehensive timeline, and bibliography, click here.

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• Published Aug. 3, 2020 Updated Aug. 19, 2020

UNCONDITIONAL The Japanese Surrender in World War II By Marc Gallicchio

Every August, newspapers are dotted with stories of Hiroshima and Nagasaki, accompanied by a well-picked-over — but never resolved — debate over whether atomic bombs were needed to end the Asia-Pacific war on American terms. What is left to learn 75 years (and with so much spilled ink) later? For Marc Gallicchio , the answer is in the domestic politics of the United States and Japan, which drive a narrative that unwinds less like a debate than a geopolitical thriller.

“Unconditional” offers a fresh perspective on how the decision to insist on “unconditional surrender” was not simply a choice between pressing the Japanese into submission or negotiating an end to the conflict. It also traces ideological battle lines that remained visible well into the atomic age as the enemy shifted from Tokyo to Moscow.

President Harry Truman believed unconditional surrender would keep the Soviet Union involved while reassuring American voters and soldiers that their sacrifices in a total war would be compensated by total victory. Disarming enemy militaries was the start; consolidating democracy abroad was the goal. Only by refusing to deal with dictators could Germany and Japan be redesigned root to branch.

But Truman faced powerful opposition from the Republican establishment, including the former president Herbert Hoover and Henry Luce, whose Time/Life media empire presaged Fox News today. Republicans fought Truman on two fronts: First, they sought to undo New Deal social and economic reforms; second, they argued that giving Japan a respectable way out of the conflict would save lives and, at the same time, block Soviet ambitions in Asia. Conservatives believed the left in the United States was more determined to use unconditional surrender to destroy Japanese feudalism than to confront Soviet ambitions — future manna from heaven for postwar redbaiters like Senator Joseph McCarthy.

Gallicchio characterizes conciliatory State Department “Japan hands” as dupes of cosmopolitan Japanese who persuaded them that Japan’s emperor was actually a progressive who would help America build a stable, anti-Communist East Asia. But New Deal Democrats believed these experts did not know what they did not know about Japan. And prefiguring neoconservatives of a later era, they insisted that only the deposition of the emperor — as part of a full transformation of the country’s political culture — would usher Japan into a peaceful postwar community of nations.

The left-wing journalist I. F. Stone joined the fray. He railed against “reactionaries” who he said were determined to stir a red scare to roll back reform in America, purge progressive officials and deliver a conditional unconditional surrender to their friends in Tokyo. Gallicchio, the author of several books of military history, sorts out these players — and many others — with great clarity, noting that Truman played coyly with both sides as the war shifted decisively in the Allies’ favor.

Convinced that the Japanese would not surrender short of a final, decisive battle — or (once the A-bomb was available) a final incendiary event — Truman was unwilling to suggest American resolve was weakening. He used the Potsdam Declaration of July to remind the Japanese that only more devastation awaited if they held out. He understood that imperial cooperation would ease the difficult task of disarming 5.5 million Japanese soldiers — and he ultimately spared Hirohito — but he would not guarantee the emperor’s status before the end of the war.

Japan’s leaders felt little urgency. The imperial military had amassed an astonishing number of troops for a desperate homeland defense, while politicians fantasized about a Soviet-brokered peace. Lacking a guarantee of his safety, the emperor supported the effort to reach out to Moscow and busied himself with protecting sacred relics. Even after the first A-bomb incinerated Hiroshima, he asked the government to seek Allied concessions, underscoring Gallicchio’s claim that Japanese officials “seemed uncertain of what they were doing.”

With the Red Army suddenly deep into Manchuria, Japanese leaders were weighing evaporating options when the second bomb incinerated Nagasaki. What had been chimeric was now clearly delusional.

The emperor finally intervened. Overruling his generals, he broadcast a decree Gallicchio sardonically calls “almost comically evasive” because it omitted the words “surrender” and “defeat.” While many Japanese were confused and saddened, they accepted the emperor’s most famous edict to “endure the unendurable.” Some military officers, though, committed suicide after a failed mutiny on what has become known as “Japan’s longest day.”

Gallicchio deftly recounts how debate about Truman’s decision persisted well after the surrender. In Japan, aggressive reforms early in the occupation were opposed by the same Western-educated Japanese who had influenced America’s Japan hands. These elites were keen on defanging the Japanese military, but tried to block land, labor and electoral change.

“Unconditional” documents how conservatives back home targeted New Dealers within the occupation as Communist sympathizers and hatched revisionist histories of Truman’s motives, exaggerating the emperor’s antimilitarism. Their revisionism was replaced by a New Left brand in the 1960s. Truman, some now argued, instigated the Cold War by trying to intimidate the Soviet Union with America’s nuclear might.

In 1995, a half-century after the war, the debate was reignited when curators at the Smithsonian Institution tried unsuccessfully to use this account of United States aggression to frame an exhibition in which the Enola Gay, the plane that dropped the A-bomb on Hiroshima, was the leading artifact. “Unconditional” is a sharp reminder of the power, imperfection and politicization of historical narrative — and of the way debates can continue long after history’s witnesses have left the stage.

Richard J. Samuels directs the M.I.T. Center for International Studies. His latest book, “Special Duty: A History of the Japanese Intelligence Community,” was published last year.

UNCONDITIONAL The Japanese Surrender in World War II By Marc Gallicchio 288 pp. Oxford University Press. $27.95.

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Was the US Justified in Dropping the Atomic Bomb? Essay

Introduction, works cited.

The United States is widely recognized for ending World War II by dropping atomic bombs on two cities in Japan; however, they also caused incalculable human anguish difficult to justify. This action introduced new concerns and conceptions regarding how wars would be fought in the future, called into question whether the human race would survive much into the future and began a worldwide debate regarding whether the action was truly warranted.

Questions regarding the bombings are multifaceted. While it is often suggested that the atomic bomb was the only means available to secure Japanese surrender, Japan at the time was requesting only one concession from the West – that it be allowed to retain its emperor as head of state. Had this been done, could the wanton destruction of a predominantly civilian population be avoided? Considering this, it is necessary to question the true motivations of President Truman in his authorization of the bombs’ use. Was it actually to bring about a swift end to the protracted deadly conflict and ultimately intended to save lives, American and Japanese, that would be lost in an overland confrontation? Or was it, as has been suggested, more a decision based on keeping the Soviet Union from having any input regarding the division of post-war Asia as it had in dividing post-war Europe? Even if the first bomb, dropped on Hiroshima could be argued as justifiable, the widespread destruction and collateral damage was devastating enough that the second bomb, dropped on Nagasaki, should have been called back.

The primary reasoning given for the bombs’ use was that it would save thousands of American and Japanese lives by eliminating the need for an overland confrontation between the two opposing armies. While the battles for the Philippines and Okinawa were taking place, President Truman, who had become president following the death of Roosevelt, was considering an invasion of the Japanese mainland. By now, the U.S. Navy had ships stationed just off the Japanese coast while its submarines were deployed in the Sea of Japan. Because the battles at Iwo Jima and Okinawa were very fierce, it was estimated that half a million to a million soldiers would be killed if the scheduled November 1, 1945 invasion of Japan occurred (“Decision to Drop”, 2003). However, what fails to enter the discussion is the comparison of the types of victims involved – enlisted men or civilians. The first blast leveled more than half of Hiroshima. Seventy thousand of its citizens were instantaneously killed.

On August 9, another bomb destroyed Nagasaki (Truman, 1945). Deliberately attacking a civilian population is not considered morally acceptable regardless of any real or perceived outcomes. This view was and remains popularly held by both American civilians and the military. Even for those individuals who do not find it difficult to accept that the first bomb was necessary, though, the issue regarding the morality of the second bombing remains in dispute. The saving of lives was not at issue by the time the second bomb was dropped.

In addition to considering the overland attack, President Truman and his staff realized that if the Japanese would surrender prior to Soviet involvement in the Asian field, set for August 15, Russia could not demand a part in the post-war settlement. At the same time, by 1945, the U.S. was a country weary of war and its citizens had become deeply prejudiced against both the Japanese and Germans, believing that both types of peoples were inherently evil. Following the end of the war, a poll conducted by Fortune Magazine found that nearly a quarter of the American people thought that the U.S. should have used “many more” atomic bombs on the Japanese before that country had the opportunity to surrender (Dower, 1986: 54). These polling results accurately reflected the intense hatred that Americans directed towards the Japanese people during the conflict. President Truman himself was not immune to these feelings of resentment towards the Japanese. In July 1945, less than a week prior to the Hiroshima bombing, Truman wrote in his diary describing the Japanese people as “savages, ruthless, merciless, and fanatic” (Dower, 1986: 142). When America unleashed the atomic bomb on Japan, the act infuriated the Soviet Union because it wanted its say just as it had in the carving up of Eastern Europe.

In addition to unleashing catastrophic damage upon the people of Japan, the dropping of the bombs was the beginning of the Cold War between the Soviet Union and the U.S.

Although Truman shared a similar bias against the Japanese as did the American public, his intent was not to drop such a devastating bomb on civilian areas. “We have discovered the most terrible bomb in the history of the world.

I have told the Secretary of War, Mr. [Henry] Stimson, to use it so that military objectives and soldiers and sailors are the target and not women and children. The target will be a purely military one” (Truman, 1945). Both Hiroshima and Nagasaki were cities that produced military armaments but, of course, the devastation went well beyond military targets. It could be that the President and others did not realize the full power of the atomic bomb or simply did not care if the collateral damage went well beyond its intended target. No one will ever know and the answer can only be speculative. It is contingent on whether one relies on the written words of the President as proof of actual intent or one assumes that the bombing of civilians was justified by the President and/or Stimson given the excessively racist overtones that emanated throughout the country at that time. In addition to whatever personal feelings Truman had regarding the Japanese, he also had political consequences to consider in his decision to utilize the atomic bomb. The American public, according to polls taken at that time, supported by an overwhelming margin that the U.S. should only agree to an ‘unconditional surrender’ by Japan. This and the predominant anti-Japanese sentiment among most Americans assured that there would be little political backlash by ordering the bomb to be dropped.

Furthermore, Truman would have faced an uphill political battle attempting to explain to voters the reasoning for spending more than two billion dollars for creating a bomb that would not be used, particularly if many more American lives were lost had the war continued which, at the time was considered a very real possibility (Loebs, 1995: 8-9).

Also supporting the decision, the Japanese had amassed nine divisions comprised of 600,000 heavily equipped forces in southern Japan prior to the bombing of Hiroshima in preparation for a land attack. The speed at which this incredible number of troops and arms were assimilated deeply concerned Truman and the U.S. military who had previously expected far less resistance when planning Operation Olympic, the Japanese invasion force (Loebs, 1995). Surprised once by the continued determination and ability of the Japanese military, Truman did not want to be surprised yet again by an even larger resistance than was thought which the allies could encounter as it drove further north towards Tokyo. Truman considered the possibility that he could send many thousands of young Americans to their deaths in a final conflict that may not be winnable at all and could easily stretch out for many months or years. The Japanese not only had a large number of soldiers ready to defend their homeland, but they were also well-equipped and possessed strong supply lines so as to sustain a long-term attack. One can only imagine the carnage that would have ensued during a full-out battle of this magnitude had it occurred. The ferocious battles of Okinawa and Iwo Jima would have seemed as just a warm-up compared to a Japanese invasion.

Despite all these justifications, by the summer of 1945, the Japanese were in dire straits, militarily and economically. The U.S. had won great victories at Okinawa and Iwo Jima, killed hundreds of thousands of Japanese soldiers and had a full naval blockade of Japan’s mainland.

Shortages of everything, from oil for the machines to food supplies for the soldiers, had all but brought the Japanese empire to its knees, but its military showed no signs of quitting. In each battle, its soldiers fought ferociously to the last man in a victory or death mentality and suicide (kamikaze) missions were common. This led the American leaders to believe that an entire takeover of the Japanese island was necessary for final victory. The U.S. was well aware of the fanaticism displayed by the Japanese; therefore, military leaders were not anxious to encounter an entire population of a country that possessed this mentality and were militarized as well. The avoidance of this ensuing confrontation and the war-weariness of the American public is the common justifications for dropping the bombs. Finally, “it was the destruction of Hiroshima that finally brought Emperor Hirohito to confront the Japanese military and order the surrender of Japan” (Loebs, 1995: 10). Thus, it was and is argued that the atomic bombs ultimately saved many American and Japanese lives.

It has been argued that the decision to drop the atomic bomb actually gave little regard to the civilian population, was unnecessary and was based largely upon the Soviet’s aspirations in the region. The U.S. military had been unceasingly fire-bombing major cities in Japan including Tokyo for months leading up to the use of the atomic bomb. This massive bombing attack knowingly killed civilians by the hundreds of thousands and the tactic, along with the impenetrable naval blockade, would have eventually brought the war to an end without the need for a land assault. Of course this eventuality can only be argued because it can never be known if maintaining an attack with traditional bombing methods and a blockade of the seas would have forced the Japanese to surrender unconditionally. It is possible but many more Japanese civilians, probably numbering in the millions, would have been killed in the process. In addition, had the war been prolonged, the threat posed by the Soviets was imminent and daunting. Had they had a hand in postwar affairs in Asia, the boundaries of the world would be very different today. The Russian army had entered Korea a few days prior to August 6; the day of the atomic bomb on Hiroshima (Zimmerman, 2000). Within a short time, it would have conquered enough Korean territory to be able to claim a negotiating position at the post-war peace talks. Had this scenario occurred, the Soviets had plans in place to occupy both Japan and Korea to the familiar 38th parallel.

This would have been an offer the Allies couldn’t refuse because Soviet troops would already be occupying this territory. “The destruction of Hiroshima and Nagasaki served three purposes: it terminated the conflict instantly, saving American lives; it insured a united Japan rather than leaving half of the country to the same fate as North Korea; and perhaps it provided an example which has deterred the use of nuclear arms for 55 years” (Zimmerman, 2000).

More than 60 years have elapsed since the atomic bomb was dropped, a long time to second guess and point out the flawed reasoning in that momentous decision. However, many prominent However, Americans at that time questioned the wisdom of using such a horrific weapon given the circumstances.

Top-level World War II military leaders such as Douglas MacArthur, William Halsey, William Leahy and Dwight Eisenhower amongst others, believed the bomb to be totally unnecessary from a military point of view (Takaki, 1995: 3-4, 30-31). The President of the Chiefs of Staff, Navy Admiral Leahy, in his address to the combined U.K. and U.S. Chiefs of Staff expressed his thoughts regarding the use of the atomic bomb. “The use of this barbarous weapon at Hiroshima and Nagasaki was of no material assistance in our war against Japan. The Japanese were already defeated and ready to surrender. In being the first to use it, we adopted an ethical standard common to the barbarians of the Dark Ages.

I was not taught to make war in that fashion, and wars cannot be won by destroying women and children” (Alperovitz, 2005: 3). In 1946, the Commander U.S. Third Fleet, Admiral Halsey Commander publicly announced that “The first atomic bomb was an unnecessary experiment. It was a mistake to ever drop it. The scientists had this toy and they wanted to try it out, so they dropped it” (Alperovitz, 2005: 331). The Supreme Commander of the Pacific Fleet in World War II, Admiral Chester W. Nimitz stated at an address given on October 5 at the Washington Monument, “The Japanese had, in fact, already sued for peace before the atomic age was announced to the world with the destruction of Hiroshima and before the Russian entry into the war. The atomic bomb played no decisive part, from a purely military standpoint, in the defeat of Japan” (Alperovitz, 2005: 329). Eisenhower was of the same opinion as to these other prominent commanders and vocally joined his colleges citing morality-based objections.

Japan was very close to surrendering by the time the atomic bombs were dropped on the cities of Hiroshima and Nagasaki. Sixty of its larger cities had already been destroyed by the use of conventional bombing runs and the naval blockade had destroyed Japan’s economy. The Soviet Union was busy fighting the Japanese, but these battles were fought in China and were far from a mainland invasion as Russia had also been weakened following its war with Germany. If the U.S. would have allowed the Japanese to retain its Emperor, the country would have surrendered before the first bomb was dropped, a slight concession given the devastating consequences. A demonstration bombing in a remote area of Japan would have been sufficient to affect surrender without using it on a civilian population. The second bomb was entirely unnecessary even if the first could be justified. Simply put, the Japanese people were pawns used in a political power play, the first such power plays of the ‘Cold War’ between the U.S. and Soviet Union.

Alperovitz, Gar. “The Decision to Use the Atomic Bomb.” (1st Ed.). New York: Routledge. (2005).

“(The) Decision to Drop.” National Atomic Museum. (2003). Web.

Dower, John W. “War Without Mercy.” New York: Pantheon Books. (1986).

Loebs, Bruce. “Hiroshima & Nagasaki: One Necessary Evil, One Tragic Mistake.” Commonweal Journal. LookSmart Articles. (1995). Web.

Takaki, Ronald. “Hiroshima: Why America Dropped the Atomic Bomb.” Boston: Little, Brown and Company. (1995).

Truman, Harry. “Atomic Bomb – Truman Press Release: August 6, 1945.” Truman Presidential Museum and Library. (1945). Web.

Zimmerman, Peter D. “The Atomic Bomb.” St. Petersburg Times. (2000). Web.

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IvyPanda. (2021, September 21). Was the US Justified in Dropping the Atomic Bomb? https://ivypanda.com/essays/was-the-us-justified-in-dropping-the-atomic-bomb/

"Was the US Justified in Dropping the Atomic Bomb?" IvyPanda , 21 Sept. 2021, ivypanda.com/essays/was-the-us-justified-in-dropping-the-atomic-bomb/.

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IvyPanda . 2021. "Was the US Justified in Dropping the Atomic Bomb?" September 21, 2021. https://ivypanda.com/essays/was-the-us-justified-in-dropping-the-atomic-bomb/.

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Bibliography

IvyPanda . "Was the US Justified in Dropping the Atomic Bomb?" September 21, 2021. https://ivypanda.com/essays/was-the-us-justified-in-dropping-the-atomic-bomb/.

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Lesson Plan: Was using the atomic bomb on Japan necessary for ending World War II?

The Development of the Atomic Bomb

The Pare Lorentz Center at the Franklin D. Roosevelt Presidential Library and Museum added narration to archival film, photographs and audio recordings to tell the story of FDR during World War II. This segment explains the events that led to the development of the atomic bomb.

Description

This lesson looks at President Truman’s decision to drop atomic bombs on Hiroshima and Nagasaki during World War II. Students will view videos to understand the origins of the atomic bomb, American military strategy in the Pacific and the historical debate over the decision to use nuclear weapons on Japans. Students will explore arguments in this debate and answer the question: Was using the atomic bomb on Japan necessary for ending World War II?

To begin class, have the students brainstorm answers to the following question:

Describe the fighting and important battles that took place between Japan and the Allied forces during World War II.

• Describe what you know about the atomic bomb.

INTRODUCTION:

Review the students’ answers to the warm-up and provide a brief overview of the atomic bomb, the Allied strategy in the Pacific and significant battles prior to 1945.

To provide with a fuller understanding of the Manhattan Project and the War in the Pacific, have the students view each of the following introductory video clips and answer the questions associated with each. Students can use the handout linked below to access the videos and answer the questions.

HANDOUT: The Decision to Use the Atomic Bomb (Google Doc)

VIDEO CLIP 1: The Development of the Atomic Bomb (2:36)

Describe the origins of the atomic bomb in the United States.

What was the plan for using the atomic bomb in World War II? What events caused this plan to change?

• Describe the devastation caused by dropping the atomic bomb on Hiroshima and Nagasaki.

VIDEO CLIP 2: The Interim Committee and the Decision to Use the Atomic Bomb (5:22)

What was the Interim Committee? What was its purpose?

What would be the benefit of a demonstration of the atomic bomb?

Describe the recommendation made by the Interim Committee.

Explain Harry Truman’s role in the atomic bomb prior to becoming president.

• What factors influenced the decision to drop the atomic bomb on Japan?

VIDEO CLIP 3: The End of World War II in Japan (3:55)

Describe the fighting that occurred in the Pacific in 1945 as American forces approached the Japanese home islands.

How do the artifacts in the museum reflect the impact of the war on families in the United States?

What factors contributed to the different American plans to end the war?

What was the Manhattan Project?

• Describe the timeline of events that occurred in August 1945.

EXPLORATION:

After answering the previous questions, students should use the chart on the handout to take notes to help them answer the following question: Was using the atomic bomb on Japan necessary for ending World War II?

VIDEO CLIP 4: The Debate over the Decision to Drop the Atomic Bomb on Japan (3:17)

What are the two competing theories on the use of the atomic bomb?

Describe the “traditional” arguments for dropping the atomic bomb on Japan.

• Describe the “revisionist” arguments for not dropping the atomic bomb on Japan.

VIDEO CLIP 5: Reasons for Dropping the Atomic Bomb (4:15)

VIDEO CLIP 6: The Soviet Invasion of Manchuria

VIDEO CLIP 7: The Atomic Bomb and the End of World War II (1:43)

VIDEO CLIP 8: Alternatives to Using the Atomic Bomb (3:23)

APPLICATION AND CONCLUSION:

Using their notes on the handout, the students will respond to the following prompt:

Was the dropping of the atomic bombs on Hiroshima and Nagasaki necessary to end World War II?

Teachers can choose to have students address this prompt using the following options:

Written essay

Speech or presentation

Short video

• Infographic or poster

EXTENSION/ALTERNATIVE ACTIVITIES:

Online Discussion Board- Using the same prompt listed above, have the students write a post explaining their position. They should explain the reasons why they believe this. Once students have posted their arguments, each student should respond to at least three other students’ posts and explain why they agree or disagree with their arguments. They should use examples and information from the videos when they respond.

Primary Source Interpretation- View the video clips linked below of a Hiroshima survivor, American veterans and a U.S. Department of War film. Answer the questions listed below.

Clip: Hiroshima Survivor and Activist Setsuko Thurlow (4:53)

Clip: Tale of Two Cities- The Bombing of Nagasaki (3:45)

Clip: The Atomic Bomb and the Invasion of Japan (2:57)

How does each clip describe the bombings?

• How do the these perspectives compare to each other?

ADDITIONAL PROMPTS:

How did the bombings of Hiroshima and Nagasaki change the world?

In what ways did the use of the atomic bomb contribute to the Cold War between the U.S and Soviet Union?

• How has the interpretation of the bombings of Hiroshima and Nagasaki changed since 1945? Why do you think this is?

Related Article

• Harry S Truman’s Decision to Use the Atomic Bomb (U.S. National Park Service)

Additional Resources

• Lesson Plan: World War II
• On This Day: The Manhattan Project and the Atomic Bomb
• On This Day: The Yalta Conference
• Atomic Bomb
• Battle Of Okinawa
• Battle Of Saipan
• Harry Truman
• Japanese Home Islands
• Joseph Stalin
• Kwantung Army
• Manhattan Project
• Revisionist
• Robert Oppenheimer
• Soviet Union
• Winston Churchill
• World War 2
• Yalta Conference

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• Copy URL https://www.pbs.org/newshour/world/what-are-tactical-nuclear-weapons-and-why-did-russia-announce-it-would-hold-drills

What are tactical nuclear weapons and why did Russia announce it would hold drills?

Russia’s Defense Ministry said Monday that the military would hold drills involving tactical nuclear weapons — the first time such an exercise has been publicly announced by Moscow.

A look at tactical nuclear weapons and the part they play in the Kremlin’s political messaging.

What are tactical nuclear weapons?

Unlike nuclear-tipped intercontinental ballistic missiles that can destroy entire cities, tactical nuclear weapons for use against troops on the battlefield are less powerful and can have a yield as small as about 1 kiloton. The U.S. bomb dropped on Hiroshima during World War II was 15 kilotons.

NEWS WRAP: Russia says it will hold drills to simulate nuclear weapon use

Such battlefield nuclear weapons — aerial bombs, warheads for short-range missiles or artillery munitions — can be very compact. Their small size allows them to be discreetly carried on a truck or plane.

Unlike strategic weapons, which have been subject to arms control agreements between Moscow and Washington, tactical weapons never have been limited by any such pacts, and Russia hasn’t released their numbers or any other specifics related to them.

What has Putin said about nuclear weapons?

Since launching the full-scale invasion of Ukraine on Feb. 24, 2022, Russian President Vladimir Putin has repeatedly reminded Western nations about Moscow’s nuclear might in a bid to discourage them from increasing military support to Kyiv.

Early on in the war, Putin frequently referenced Moscow’s nuclear arsenal by vowing repeatedly to use “all means” necessary to protect Russia. But he later toned down his statements as Ukraine’s offensive last summer failed to reach its goals and Russia scored more gains on the battlefield.

READ MORE: UN nuclear watchdog leader visits Iran over stifled monitoring and rising Mideast tensions

Moscow’s defense doctrine envisages a nuclear response to an atomic strike or even an attack with conventional weapons that “threaten the very existence of the Russian state.” That vague wording has led some pro-Kremlin Russian experts to urge Putin to sharpen it to force the West to take the warnings more seriously.

Putin said last fall that he sees no reason for such a change.

“There is no situation in which anything would threaten Russian statehood and the existence of the Russian state,” he said. “I think that no person of sober mind and clear memory could have an idea to use nuclear weapons against Russia.”

Why did Russia send nuclear weapons to Belarus?

Last year, Russia moved some of its tactical nuclear weapons into the territory of Belarus, an ally that neighbors Ukraine and NATO members Poland, Latvia and Lithuania.

Belarus’ authoritarian president, Alexander Lukashenko, had long urged Moscow to station nuclear weapons in his country, which has close military ties with Russia and served as a staging ground for the war in Ukraine.

READ MORE: Russia vetoes UN resolution on preventing nuclear arms race in space

Both Putin and Lukashenko said that nuclear weapons deployment to Belarus was intended to counter perceived Western threats. Last year, Putin specifically linked the move to the U.K. government’s decision to provide Ukraine with armor-piercing shells containing depleted uranium.

Neither leader said how many were moved — only that Soviet-era facilities in the country were readied to accommodate them, and that Belarusian pilots and missile crews were trained to use them. The weapons have remained under Russian military control.

The deployment of tactical nuclear weapons to Belarus, which has a 1,084-kilometer (673-mile) border with Ukraine, would allow Russian aircraft and missiles to reach potential targets there more easily and quickly, if Moscow decides to use them. It has also extended Russia’s capability to target several NATO allies in Eastern and Central Europe.

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News Wrap: Russia says it will hold drills to simulate nuclear weapon use

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