Not for bombing military targets. But the indiscriminate slaughter of civilians is a war crime, and should be condemned no matter who does it.
I know the debate goes on. For instance, you read this, from Truman's Diary:
Truman Diary, July 25, 1945 –
President Truman told his diary that he had ordered the bomb dropped on a "purely military" target, so that "military objectives and soldiers and sailors are the target and not women and children. Even if the Japs are savages, ruthless, merciless and fanatic, we as the leader of the world for the common welfare cannot drop that terrible bomb on the old capital or the new. The target will be a purely military one!
Official Bombing Order, July 25, 1945 –
The bombing order issued to General Spaatz made no mention of targeting military objectives or sparing civilians. The cities themselves were the targets.
I dunno what childish version of war you think reality has, but it's not your fantasies.
It appears my childish view would be Truman's view as of July 25, 1945.
Truman understood that cities themselves are military targets. Strategic ones. What you pasted only reinforced that.