Revisionist historians have held that since the Japanese government was, by this time, seeking desperately to leave the war, employing the atomic bomb against Japan was unnecessary. Intercepts of diplomatic messages, however, indicate that Japan had still not reached the decision to surrender when the first bomb was dropped. Although Emperor Hirohito and his principal advisers had concluded that Japan could not win the war, they hoped for a negotiated settlement after a last "decisive battle" that would force the Allies to grant more favorable peace terms. On 28 July, the Japanese government formally rejected acceptance of the Potsdam Declaration, as demanded by U.S. President Harry S Truman two days before—a refusal that led Truman to decide to employ the atomic bomb.
On 6 August 1945, the United States dropped an atomic bomb on the Japanese city of Hiroshima. About 100,000 people perished outright or died later from radiation effects; another 40,000 were injured, and most of the remaining population suffered some long-term radiation damage. Even so, this carnage was less than that inflicted in the firebombing of Tokyo in March 1945. Meeting with the emperor, the army leadership still strongly opposed accepting the Potsdam Declaration.
On 8 August, the Soviet Union declared war on Japan, with Josef Stalin honoring his pledge at Yalta to enter the war against Japan "two or three months after the defeat of Germany." One day later, Soviet troops invaded Manchuria in force. That same day, a B-19 bomber dropped a second atomic bomb, on Nagaski. The blast there claimed about 70,000 dead, either killed outright or dying later from radiation, and it injured as many more.
After prolonged meetings with his top advisers, Emperor Hirohito made the decision for peace on 14 August. He stated that as onerous as it would be to order the surrender, have the Japanese homeland occupied, and see loyal servants face possible trial as war criminals, these considerations had to be weighed against the devastation facing the Japanese people in a continuation of the war.
Braving possible assassination by high-level fanatics determined to stage a coup d'état and fight to the end, Hirohito communicated this decision over the radio on 15 August at noon Tokyo time, the first occasion on which the Japanese people had heard his voice. In the course of his remarks, Hirohito said, "We have resolved to pave the way for a general peace for all generations to come by enduring the unendurable and suffering what is unsufferable." He referred specifically to the atomic bombs when he said, "Moreover, the enemy has begun to employ a new and more cruel bomb, the power of which to do damage is indeed incalculable, taking the toll of many innocent lives." On 2 September, the final terms of surrender were signed aboard the battleship Missouri in Tokyo Bay, and the Japanese islands came under the rule of a U.S. army of occupation.
Spencer C. Tucker
Butow, Robert J. C. Japan's Decision to Surrender. Stanford, CA: Stanford University Press, 1954.; Craig, William. The Fall of Japan. New York: Dial Press, 1967.; Frank, Richard B. Downfall: The End of the Imperial Japanese Empire. New York: Random House, 1999.