I'd love to see a movie inside the Truman administration about dropping the bomb. Japan would've surrendered soon and even if they didn't their forces were decimated; a full scale invasion would never have been necessary. In reality Truman dropped the bomb to show the Soviets that they had the capability to create these weapons and that they better back off.
There is zero evidence that anyone in the Truman administration or the Joint Chiefs thought that Japan was going to surrender soon or that an invasion would be unnecessary. Defeated Japanese forces in the field had yielded remarkably few prisoners, they seemed to prefer to die, and civilian Japanese subjects in Saipan had jumped off cliffs when American forces took the island, all lending to serious questions about whether the Japanese people would
ever surrender.
The B-29 fire-bombing campaign was already decimating Japanese cities, and the atomic bombs were an extension of that campaign. New and far more deadly , but an extension nonetheless. Of course there were other political and diplomatic considerations, there always are, but no credible evidence has been uncovered that Truman thought that the war would end without the bombing campaign and the invasion. His biggest consideration WRT the USSR was to get Japan to surrender before the Soviets got a bigger role in the Pacific war and a bigger claim on post-war Japan.
Truman was always terrible when it came to dealing with the Soviet Union and this was just another example.
Yeah, the Berlin Airlift, what an embarrassment!
That said, the stubborness of the Japanese emperor not to surrender despite having essentially no army left was moronic.
By August '45 there were enough Japanese soldiers in the home islands for over 60 infantry divisions, though they could only effectively arm about half that amount.
The emperor deserves blame, sure, but the Japanese government at that time was a dysfunctional balance between the emperor and the military. The emperor could have been assassinated or deposed in favor of a more hardline "no surrender" member of the imperial family, and in fact there were plans to do just that and it came close to happening. The a-bombs were a drastic enough new development in the war to allow the surrender/never-surrender stalemate in the war cabinet to be broken.
--Justin