The Atomic Bombs and the Soviet Invasion: What Drove Japan’s Decision to Surrender?
Tsuyoshi Hasegawa writes in Japan Focus:
Almost immediately following the end of World War II, Americans began to question the use of the atomic bomb and the circumstances surrounding the end of the Pacific War. More than half a century later, books and articles on the atomic bomb still provoke storms of debate among readers and the use of atomic weapons remains a sharply contested subject. As the 1995 controversy over the Enola Gay exhibit at the Smithsonian’s National Air and Space Museum revealed, the issues connected with the dropping of the bombs on Hiroshima and Nagasaki continue to touch a sensitive nerve in Americans. Among scholars, disagreement remains no less heated. But, on the whole, this debate has been strangely parochial, centering almost exclusively on how the U.S. leadership made the decision to drop the bombs.
There are two distinct gaps in this historiography. First, with regard to the atomic bombs, as Asada Sadao in Japan correctly observes, American historians have concentrated on the “motives” behind the use of atomic bombs, but “they have slighted the effects of the bomb.” Second, although historians have been aware of the decisive influence of both the atomic bombs and the Soviet entry into the war, they have largely sidestepped the Soviet factor, relegating it to sideshow status.
Two historians, Asada Sadao and Richard Frank, have recently confronted this issue head-on, arguing that the atomic bombing of Hiroshima had a more decisive effect on Japan’s decision to surrender than did Soviet entry into the war. This essay challenges that view. It argues that (1) the atomic bombing of Nagasaki did not have much effect on Japan’s decision; (2) of the two factors—the atomic bombing of Hiroshima and Soviet entry into the war—the Soviet invasion had a more important effect on Japan’s decision to surrender; (3) nevertheless, neither the atomic bombs nor Soviet entry into the war served as “a knock-out punch” that had a direct, decisive, and immediate effect on Japan’s decision to surrender; (4) the most important, immediate cause behind Japan’s decision to surrender were the emperor’s “sacred decision” to do so, engineered by a small group of the Japanese ruling elite; and (5) that in the calculations of this group, Soviet entry into the war provided a more powerful motivation than the atomic bombs to seek the termination of the war by accepting the terms specified in the Potsdam Proclamation.