This weekend marks the 60th anniversary of the August 6, 1945 bombing of Hiroshima. One might think that by now historians would agree on all the fundamental issues. The reality, however, is just the opposite: All the major issues involved in the decision are still very much a matter of dispute among experts. An obvious question is why this should be so after so many years.
Did the atomic bomb, in fact, cause Japan to surrender? Most Americans think the answer is self-evident. However, many historical studies–including new publications by two highly regarded scholars--challenge the conventional understanding. In a recently released Harvard University Press volume drawing upon the latest Japanese sources, for instance, Professor Tsuyohsi Hasegawa concludes that the traditional “myth cannot be supported by historical facts.” By far the most important factor forcing the decision, his research indicates, was the Soviet declaration of war against Japan on August 8, 1945, just after the Hiroshima bombing.
Similarly, Professor Herbert Bix–whose biography of Hirohito won the 2000 Pulitzer Prize for general nonfiction–also writes in a recent article that “the Soviet factor carried greater weight in the eyes of the emperor and most military leaders.”
Many Japanese historians have long judged the Soviet declaration of war to have been the straw that broke the camels back–mainly because the Japanese military feared the Red Army more than the loss of another city by aerial bombardment. (They had already shown themselves willing to sacrifice many, many cities to conventional bombing!)
An intimately related question is whether the bomb was in any event still necessary to force a surrender before an invasion. Again, most Americans believe the answer obvious–as, of course, do many historians. However, a very substantial number also disagree with this view. One of the most respected, Stanford University Professor Barton Bernstein, judges that all things considered it seems “quite probable–indeed, far more likely than not–that Japan would have surrendered before November” (when the first landing in Japan was scheduled.)
Many years ago Harvard historian Ernest R. May also concluded that the surrender decision probably resulted from the Russian attack, and that “it could not in any event been long in coming.” In his new book Hasegawa goes further: “[T]here were alternatives to the use of the bomb, alternatives that the Truman Administration for reasons of its own declined to pursue.”
(On the other hand, one recent writer, Richard Frank, argues Japan was still so militarily powerful the U.S. would ultimately have decided not to invade. He justifies the bombing not only of Hiroshima but of Nagasaki as well. Japanese historian Sadao Asada believes that “there was a possibility Japan would not have surrendered by November” on the basis of the Russian attack alone.)
What did the U.S. military think? Here there is also dispute. We actually know very little about the views of the military at the time. However, after the war many–indeed, most–of the top World War II Generals and Admirals involved criticized the decision. One of the most famous was General Eisenhower, who repeatedly stated that he urged the bomb not be used: “[I]t wasn’t necessary to hit them with that awful thing.” The well-known “hawk,” General Curtis LeMay, publically declared that the war would have been over in two weeks, and that the atomic bomb had nothing to do with bringing about surrender. President Truman’s friend and Chief of Staff, five star Admiral William D. Leahy was deeply angered: 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. . . [I]n being the first to use it, we . . . adopted an ethical standard common to the barbarians of the Dark Ages.”
Some historians believe such statements may have been made partly to justify postwar funding requests by the various military services. Several years after the war General George C. Marshall did state publicly that he believed the bombings were necessary. On the other hand, long before the atomic bomb was used Leahy’s diary shows he judged the war could be ended. And Marshall is on record months before Hiroshima as suggesting that “these weapons might first be used against straight military objectives such as a large naval installation and then if no complete result was derived from the effect of that... we ought to designate a number of large manufacturing areas from which the people would be warned to leave--telling the Japanese that we intend to destroy such centers....”
Why was the bomb used? The conventional view, of course, is that it was to save as many lives as possible. But if this is so, several historians now ask, why did President Truman and his chief adviser Secretary of State James Byrnes make it harder for Japan to surrender? Specifically, why did they remove assurances for the Japanese emperor from the July 1945 Potsdam Proclamation warning Japan to surrender? The assurances were strongly recommended by U.S. and British military leaders, and removing them, they knew, would make it all but impossible for Japan to end the war.
A traditional theory has been that the President feared political criticism if he provided assurances to the emperor. But, other historians note, leading Republicans were for–not against–clarifying the terms to achieve a surrender, and were calling for this publicly. Moreover, American leaders always knew the emperor would be needed to order a surrender–and, of course, in the end they did agree to an understanding which allowed such assurances: Japan still has an emperor.
Hasegawa believes the assurances were taken out of the Potsdam Proclamation precisely because American leaders wanted to have the warning rejected so as to justify the bombing–and, further, that they saw the bomb as a way to end the war before Russia could join the fighting. There is other evidence suggesting that policy makers, especially Secretary of State Byrnes, wanted to use the bomb to “make the Russians more manageable in Europe”--as he told one scientist.
(Full disclosure: My own view–as one of the historians involved in the debate--is that the bombings were unnecessary and that American policy makers were advised at the time that a combination of assurances for the emperor plus the forthcoming Russian declaration of war would likely bring about surrender in the three months available before the invasion could begin. I also believe the evidence is strong, but not conclusive, that American leaders saw the bomb above all as a way to impress the Russians and also as a way to end the war before the Red Army got very far into Manchuria.)
Why are historians still struggling over these issues? One reason is that few nations find it easy to come to terms with questionable actions in their past. Nor is this a simple left-right debate. In recent years liberals have been critical of the decision. At the time The Nation magazine defended the bombing while many conservative publications criticized it–including Human Events, and later, the National Review. “The use of the atomic bomb, with its indiscriminate killing of women and children, revolts my soul," former President Herbert Hoover wrote to a friend.
One of the most important reasons the issues don’t seem to get resolved has to do with the historical record. The fact is most discussions concerning the decision to use the atomic bomb were simply not recorded. Not only were such matters handled in an extremely secretive manner, they were largely handled outside the normal chain of command. There is also evidence of the manipulation of some documents and of missing documents in certain cases–and in some instances, evidence that documents were destroyed.
Perhaps one day we will know more and the long debate over Hiroshima will come to an end. We are unlikely, I think, to discover new official sources. However, a new generation of scholars may well be able to ferret out diaries, letters, or additional personal papers in the attics or basements of descendants of some of the men involved. An even more interesting possibility is that the President’s daughter Margaret will one day donate additional papers to the Truman Library. (In her own writing Margaret reports details which seem clearly to be based on documentary sources. However, she has so far refused to respond to inquiries from historians asking for access to these.) A third possibility is that if, as some believe, the Soviets bugged the Truman villa near Potsdam, Germany (or the villas of other American or British officials who were there for the July 1945 meetings just before the bombings), there may be tapes or transcriptions of some key conversations in NKVD or other files in the Russian archives.
Gar Alperovitz, Lionel R. Bauman Professor of Political Economy at the University of Maryland is the author of Atomic Diplomacy: Hiroshima and Potsdam and of The Decision to Use the Atomic Bomb.