What If the United States Had Told the Soviet Union About the Bomb?

With U.S. President Barack Obama’s trip to Japan for the G7 summit and his visit to Hiroshima, a first for a sitting U.S. president, there has been extensive debate both among scholars and in the public arena about the justification for the use of nuclear weapons against Japan. This debate mirrors the ones that were had within governmental and scientific circles in the months before U.S. President Harry S. Truman made the ultimate decision to drop the first atomic bomb on Hiroshima, Japan on August 6, 1945.

Within that larger conversation–itself part military, part political, and part moral–was a discussion as to whether the Soviet Union should be informed ahead of the nuclear bomb’s use. Such a question might seem trite now – with the benefit of hindsight, and declassified documents, we now know that as the United States raced to complete the bomb in 1945, the Soviets were studying stolen U.S. blueprints and tinkering with their own device.

But at the time, U.S. and British leaders believed the Soviets were ignorant of the nuclear bomb’s progress and some worried (again without knowing the arms race had already begun) that neglecting to tell the Soviets about the bomb would all but ensure an arms race after the war.

Indeed, two reports drafted by different panels of scientists involved in the Manhattan Project – which each reached different conclusions–recommended cluing the Soviets in.

The Franck Report – written by group of seven scientists at the University of Chicago and dated June 11, 1945 – judged “an early, unannounced attack against Japan inadvisable.” The report was drafted by Eugene Rabinowitch and the product of intense meetings in early June 1945 chaired by James Franck, including Donald J. Hughes, J. J. Nickson, Glenn T. Seaborg, J. C. Stearns, and Leo Szilard (who would the next month draft a petition to the president urging him to not use the bomb, signed by 69 other nuclear scientists).

The Franck report recommended a demonstration detonation, not the least because it would make the likelihood of an international agreement to control nuclear weapons more likely:

…from the “optimistic” point of view – looking forward to an international agreement on prevention of nuclear warfare – the military advantages and the saving of American lives, achieved by the sudden use of atomic bombs against Japan, may be outweighed by the ensuing loss of confidence and wave of horror and repulsion, sweeping over the rest of the world, and perhaps dividing even the public opinion at home.

From this point of view a demonstration of the new weapon may best be made before the eyes of representatives of all United Nations, on the desert or a barren island. The best possible atmosphere for the achievement of an international agreement could be achieved if America would be able to say to the world, “You see what weapon we had but did not use. We are ready to renounce its use in the future and to join other nations in working out adequate supervision of the use of this nuclear weapon.”

…If no international agreement is concluded immediately after the first demonstration, this will mean a flying start of an unlimited armaments race.

On the direct subject of Russia–with which this arms race was sure to be – the report commented that “Russia and China are the only great nations which could survive a nuclear attack,” but “there is no doubt that Russia, too, will shudder at the possibility of a sudden disintegration of Moscow and Leningrad…” Therefore, the report continued, “only lack of mutual trust, and not lack of desire for agreement, can stand in the path of an efficient agreement for the prevention of nuclear warfare.”

The Franck committee believed a demonstration would be a better bet to head off an arms race than a surprise.

A second group of nuclear scientists–Arthur Compton, Ernest Lawrence, J. Robert Oppenheimer, and Enrico Fermi–arrived at a different conclusion. Where the Franck committee had set aside military arguments for the use of the bombs (“we urge that the use of nuclear bombs in this war be considered as a problem of long-range national policy rather than military expediency”), the June 16, 1945, recommendation signed by Oppenheimer states clearly “we recognize our obligation to our nation to use the weapons to help save American lives in the Japanese war.”

That conclusion, however, was followed by a recommendation “that before the weapons are used not only Britain, but also Russia, France, and China be advised that we have made considerable progress in our work on atomic weapons, that these may be ready to use during the present war, and that we would welcome suggestions as to how we can cooperate in making this development contribute to improved international relations.”

Those opposed to the unannounced use of the nuclear bomb and those convinced it was the only way to end the war both agreed the Soviets should be informed. Were they?

At the Potsdam conference in late July 1945, Truman told Stalin the United States “had a new weapon of unusual destructive force.” He didn’t mention the bomb’s atomic nature and it’s unclear if he intended to inform or to tease. According to Truman, and several other observers, Stalin didn’t seem terribly interested; he simply said he hoped they’d use it on the Japanese. British Prime Minister Winston Churchill wrote in 1953 that he “was certain therefore that at that date Stalin had no special knowledge of the vast process of research upon which the United States and Britain had been engaged for so long…” Indeed, U.S. Secretary of State James F. Byrnes remained convinced into the 1960s: “I am satisfied that Stalin did not appreciate the significance of President Truman’s statement.”

Of course, Truman and the others were not aware that shortly after his tepid response, Stalin discussed the exchange with his own advisors. In 1970, Soviet Marshal Georgy Zhukov wrote in his memoirs:

In actual fact, on returning to his quarters after this meeting Stalin, in my presence, told [Foreign Minister Vyacheslav] Molotov about his conversation with Truman. The latter reacted almost immediately. “Let them. We’ll have to talk it over with Kurchatov and get him to speed things up.”

I realized that they were talking about research on the atomic bomb.

There’s a certain tragic poetry to this chain of events. It’s no use to make specific predictions about what could have been, but it’s interesting to think what the world would have been like had these events happened in a different order. The Franck committee–whose recommendation was ultimately set aside–touched an interesting nerve regarding trust and desire in international relations. It bears repeating the line that “only lack of mutual trust, and not lack of desire for agreement, can stand in the path of an efficient agreement for the prevention of nuclear warfare.”