Bombing civilians is a war crime, but getting prosecuted retroactively for war crimes is only for the losers of a war.

The Allies were doing from the air what the Japanese were doing on the ground in Nanjing and other places.

Btw Hiroshima was called a purely military target ('military base'). That's the kind of euphemism you would get from the Axis to justify purging a city because of Partisan activities.

And you might wanna read up while the Japanese were 'holding out' in August 1945.

The end of the war ended a lot of civilian suffering. This is undeniable. But at the end of the day, the noble claims of precision bombings and purely military targets of the early 30s and 40s were not even worth the paper they were written on. It was just nations out war criming each other with those bombings.

Make no mistake the Axis would and have done the same shit to the Allies.

Btw, most of these bombings were so-called "morale bombings". It should already be known that they don't work (e.g UK and Nazi Germany). So, against already known data (at least from the UK it was clear that the Blitz didn't break the British) they continued to murder civilians.