My dad was a Marine captain, in the Pacific, ordered to invade Japan. He had PTSD nightmares about his experiences fighting the Japanese on those Pacific islands for the rest of his life.
I likely wouldn't be here if they had not dropped The Bombs.
Sorry about the loss of civilian life, but the Japanese brought that on themselves. They were not the most civilized of conquerors during the war, so I suspect the Australian, Maylasian and other civilians they encountered would agree with Truman's decision.
I doubt very much if Mr Trump has the guts or the intelligence to make a decision like that. I'm positive he doesn't have the moral character.