The Skeptical Alchemist posted this video, which has some significance for me since I was in Hiroshima less than 2 weeks ago.
Say what you want about the need to end the war, the expected casualties during an invasion, or whatever other rationalizations you like. But consider this question, by Leó Szilárd:
“Suppose Germany had developed two bombs before we had any bombs. And suppose Germany had dropped one bomb, say, on Rochester and the other on Buffalo, and then having run out of bombs she would have lost the war. Can anyone doubt that we would then have defined the dropping of atomic bombs on cities as a war crime, and that we would have sentenced the Germans who were guilty of this crime to death at Nuremberg and hanged them?”