he United States and the Axis powers had abandoned any pretext of preserving non-combatant immunity in warfare. The strategic bombings of urban areas was vigorously unleashed by the major powers during World War II as witnessed by the savage destruction of Dresden, Tokyo, Hamburg, Rotterdam, Nanking, and Coventry. As the violence mounted in a war without mercy, the combatants developed the concept of total war in which “soft” non-combatant, civilian populations were added to the traditional target selection of military bases, armies in the field, and key naval staging areas. Even Secretary of War Henry L. Stimson’s dramatic intercession to spare Kyoto, Japan’s ancient capital that abounded with historical and cultural treasures, from nuclear attack, was motivated to protect Japan’s historical and material artifacts and not the city’s civilian population.¹

With strategic-nuclear bombing rapidly becoming operational in the final weeks of the war, 171 scientists and support personnel from the Manhattan Engineer District (Manhattan Project) responded by disseminating a flurry of petitions, reports, memoranda, and letters.² Their purpose was to influence United States policy on how, not whether, the atomic bomb should be introduced into the Asian-Pacific War.

It will be shown that civilian and military officials, journalists, and scholars of the period have inaccurately assessed many of these documents as indicative of either unconditional opposition to the use of the atomic bomb or sharply at odds with Truman Administration policy. In particular, the petitions of physicist Leo Szilard at the Metallurgical Laboratory (Metlab) of the University of Chicago, have been variously interpreted as unalterably opposed to the use of the atomic bomb.³ A reexamination of the petitions will clearly demonstrate conditional and not unconditional opposition to attacking Japan with the atomic bomb. Furthermore, the Metallurgical Laboratory Report of the Committee on Political and Social Problems (the Franck Report) has repeatedly been assessed as unalloyed opposition to any combat role for the A-bomb. While their authors’ certainly shared misgivings in abandoning conventional warfare, it will be shown they eschewed an unconditional, absolutist rejection of the use of the atomic bomb.

One of the most detailed and important Manhattan Project documents concerning the A-bomb’s potential use was the Franck Report.⁴ James Franck, a German-refugee physicist and 1925 Nobel laureate, was the associate director of the chemistry division at Metlab and the committee chair.⁵

The Franck Report portrayed ominously the security implications of an unannounced use of nuclear weapons, was visionary in its prediction of an abbreviated American atomic monopoly, and correctly wished to harness weapons of mass destruction to an international-control regime. It advocated a warning demonstration on a “desert or a barren island” that would avoid international “horror and revulsion” against an unannounced American-nuclear attack in the Pacific.⁶ Although conceding the introduction of the A-bomb would trigger a nuclear arms race, its arguments in favor of a non-lethal test demonstration were tactical, not ethical.⁷ America’s fission bombs were too weak and “of comparatively low efficiency and small size” to “break the will” of Japan.⁸ Since many Japanese cities had already been “reduced to ashes” by conventional bombing, a surprise nuclear attack would only marginally influence Japan’s decision to surrender.⁹

However, the Franck Report avoided unconditional opposition to the use of nuclear weapons, and even recommended certain preconditions that might justify their introduction. These might include the approval of the incipient United Nations, the support of the American people, and a Japanese rejection of a surrender ultimatum: “The weapon might perhaps be used against Japan if the sanction of the United Nations (and of public opinion at home) were obtained, perhaps after a preliminary ultimatum to Japan to surrender or at least to evacuate certain regions...”¹⁰ The report also avoided recommending a modification of unconditional surrender, established at the Casablanca conference in January 1943, in order to facilitate a diplomatic solution to the war.

The Franck Report was alarmed about the potentially adverse diplomatic consequences that might ensue from a sudden nuclear attack, and counseled the administration on how best to avoid widespread opprobrium should the A-bomb be used against Japan; the government should defer combat use until the international community witnessed a technical demonstration, for this would lessen criticism particularly if “other nations may assume a share of responsibility for such a fateful decision.”¹¹ While the Metlab scientists appropriately looked beyond the military application of the bomb and considered the impact of nuclear proliferation on United States national-security policy, the Franck Report not only avoided total opposition to a nuclear offensive, but also offered recommendations on how best to use the A-bomb without America becoming a nuclear-pariah state.

Arthur Holly Compton was the 1927 Nobel laureate in physics and director of the University of Chicago’s Metlab. It was the great scientist who originated the myth that Szilard’s petition drive and the Franck Report were unconditionally opposed to any atomic attack against Japan. Compton offered highly-opinionated summaries before forwarding Metlab and Clinton Engineer Works (Clinton Laboratory in Oak Ridge, Tennessee) documents to Washington. He sent a copy of the Franck Report to George Harrison, a special consultant to Stimson and the chair, in the secretary’s absence, of the eight-person Interim Policy Committee on Atomic Energy (Interim Committee) in 1945.¹² Included was Compton’s highly subjective analysis that the report wanted “outlawed by firm international agreement,” any “permitting [of] the bombs to be used in war.” Compton distanced himself from the report by arguing that any postponement in implementing the atomic option would “make the war longer and more expensive of human lives...”¹³ Nowhere does Compton mention that the Franck Report delineated a host of specific conditions that, if implemented, could justify a B-29 A-bomb campaign against Japan.

Harrison later informed Stimson in a “Top Secret” memorandum on June 26 about the existence of the Franck Report, and also inaccurately described it as rejecting the “use of the bomb, so nearly completed, against any enemy country at this time.”¹⁴ More recently, several documentary and general histories of the atomic bomb by Barton Bernstein, Jeffrey Porro, et al., and William Sweet, excluded in their abridged reprints of the Franck Report those sections that only conditionally dissented from an A-bomb attack or that assessed the negative-diplomatic fallout that might erupt from a military demonstration.¹⁵

At Metlab in July 1945, with the decision to use the atomic bomb only weeks away, Szilard began the petition movement. A Hungarian émigré, he helped create the Manhattan Project with his early conceptualization of the nuclear-chain reaction and his drafting of the 1939 Albert Einstein letter to President Franklin D. Roosevelt—delivered by Russian-born Lehman Corporation economist Alexander Sachs.¹⁶ Szilard has been repeatedly portrayed as the Manhattan Project’s chief architect in organizing protest against the use of the atomic bomb at the end of World War II. Yet Manhattan Project documents reveal Szilard neither unconditionally opposed the atomic bombings of Japan nor significantly deviated from Truman Administration policy.

In early 1945, with Germany’s defeat a near certainty, Szilard initially attempted through an Einstein letter of introduction to meet with Roosevelt, and persuade the president that the original rationale in developing the atomic bomb had vanished. Yet the president’s death on April 12, 1945 precluded such an encounter, and Szilard subsequently initiated the petition effort with the circulation of his July 3rd petition and cover letter of July 4, 1945 among scientists from both Metlab and Clinton.¹⁷ There was an unsuccessful effort to distribute the petition at Los Alamos National Laboratory in New Mexico, which built and assembled the weapons that were used against Hiroshima and Nagasaki on August 6 and August 9, 1945. J. Robert Oppenheimer, the Los Alamos director, thwarted any petition distribution because he believed a scientist should not attempt to influence the policy-making process of the national-security elites.¹⁸

While the cover letter unambiguously denounced the immorality of using nuclear weapons in opposing “on moral grounds...the use of these bombs in the present phase of the war,”¹⁹ the actual petition was less emphatic in its opposition to abandoning conventional warfare. If Japan did not accept American-“imposed” surrender terms that consisted of vague guarantees of “peaceful pursuits in their homeland,” the United States “might require a reexamination of her position” which could lead to the use of the atomic bomb.²⁰ This first petition on a nuclear-related event did not propose an atomic warning or any concrete steps that might avoid the use of the A-bomb. Szilard, who later opposed a nuclear test-ban treaty in the 1960s that would reduce radioactive fallout and achieve some strategic stability in the wake of the Cuban Missile Crisis, did not advance any non-lethal test scenario that might have induced a Japanese surrender.²¹

In paragraph six, Szilard’s petition repeated the cover letter’s condemnation of nuclear weapons with a vituperative critique of both conventional and nonconventional-strategic bombing of Japan:

The last few years show a marked tendency toward increasing ruthlessness. At present our Air Forces, striking at the Japanese cities, are using the same methods of warfare which were condemned by American public opinion only a few years ago when applied by the Germans to the cities of England. Our use of atomic bombs in this war would carry the world a long way further on this path of ruthlessness.²²

This plea for atomic restraint only applied to using nuclear weapons “in the present phase of the war.”²³ This was consistent with the petition’s call for an American “reexamination” of its nuclear-use policy should Japan not accede to dictated terms of surrender.

At the Clinton Laboratory, Szilard’s petition triggered a vigorous response. Eighteen Clinton scientists signed a petition that supported Szilard’s effort except for the latter’s final paragraph. Similar to the Franck Report, which the signers did not see, it recommended sharing American “responsibility for use of atomic bombs...with our allies.” The amended petition, while repeating Szilard’s vague surrender terms that allowed Japan a “peaceful development in their homeland,” explicitly advocated an atomic warning prior to any A-bomb offensive:²⁴ “We...feel that our attitude is more clearly expressed if its last paragraph is replaced by the following...Convincing warnings have been given that a refusal to surrender will be followed by the use of a new weapon.”²⁵ This appeal for an atomic warning went beyond any Szilard petition. While Compton conveniently ignored the Clinton demand for an atomic warning in pursuing his own agenda of prompt, immediate use, his general characterization of its framers as “reading the minds of Mr. Truman and Mr. Stimson” accurately reflected the document’s avoidance of unconditional opposition to the use of the atomic bomb.²⁶

A Clinton “counterpetition” effort also appeared that strongly supported the unconditional use of the weapon. George W. Parker, a chemist and leader of this small but vocal group, mailed Compton a letter which has eluded historical scrutiny on July 16, 1945—the same day as the first nuclear explosion at Trinity, in the appropriately named New Mexico desert, Jornada del Muerto (Journey of Death). While not representing government policy, Parker’s explicit written support for atomic diplomacy was one of the first to appear in any World War II document. Parker was impressed with the diplomatic advantages that would accrue from unveiling such an “impressive weapon.” As a winning weapon, the A-bomb would confer an “impressive victory...[and] should inspire American diplomacy and world opinion to effectively tame the present hard-booted Russian ego which is now an embarrassing threat to plans for world security.”²⁷ Specifically rejecting an atomic warning and brushing aside fears of diplomatic isolation following the weapon’s use, Parker rejected any “political or moral issue” that might dissuade the government from authorizing an immediate use of the atomic bomb. It advocated “winning the war.”²⁸