Thanks for actually pointing out a specific atrocity committed by the Japanese, which did result in higher casualties than the bomb, though it happened over months rather than minutes, but ok, I’ll accept it.

Still, the point is, what atrocities were the Japanese capable of perpetrating at the time the bombs were dropped, that were prevented by it, and couldn’t have been prevented in a different way. There’s a big chance that the Japanese were going to surrender anyways, and if not, maybe just the threat of dropping the bomb (maybe, say, after a demonstration at sea or otherwise away from civilians) would’ve been enough.