In the summer of 1945, the most important and troubling problem that President Harry Truman faced was how to end the war against Japan on satisfactory terms as quickly as possible. It was clear to American – and Japanese – leaders that Japan could not win the war.
But Truman and his advisers still faced the formidable task of forcing a Japanese surrender, and the prospects for an early victory were grimly uncertain, even against a badly weakened enemy.The Japanese government was sharply divided. One faction favored surrendering on the sole condition that the emperor, Hirohito, be allowed to remain on his throne. A competing faction of militants insisted not only that the status of the emperor be affirmed but also that Japan should fight on in hopes of securing better surrender terms, even at a loss of tens of millions of Japanese lives. Hirohito vacillated between the opposing views without taking a clear position.
The least desirable means of forcing a surrender was an invasion of the Japanese mainland. At a meeting with high-ranking military leaders on June 18, Truman authorized a landing on the Japanese island of Kyushu in November 1945. Army Chief of Staff George C. Marshall argued convincingly that an invasion would end the war more surely and more quickly than other alternatives. But an invasion was a dreaded contingency because military experts estimated that the price would be tens of thousands of deaths among American soldiers and sailors (though, contrary to later claims, they did not tell Truman that an invasion would cause hundreds of thousands of American fatalities). The atomic bomb accomplished Truman’s primary objective. The attack on Hiroshima finally convinced Hirohito that the war must end, and his long-delayed conclusion was the decisive step in bringing about a Japanese surrender.
Without the atomic bomb, the war would have continued at a cost in American lives that Truman and the public he served would have found unacceptable.