I asked him once about the use of the bomb knowing what he would say--he agreed with it. In fact he wanted the US to use the bomb on North Vietnam during the Vietnam War.
If a million Americans and millions of Japanese had died because Truman refused to use the bomb, and the public learned that it existed, what do you think Americans would have thought of his refusal?
If I had been in Truman’s place, I might have waited a day or two longer before using the second bomb, but the outcome probably would have been the same. Even after two bombs were dropped a lot of the Japanese leadership did not want to surrender.
My father was a submariner during the war. About a fifth of all US submariners did not survive. Had the A-bombs not fallen, I might not be here today.
I’ve read that injured soldiers with up to a 40% disability would have been had to participate in the invasion. Loss of one eye was weighted as a 30% disability.