I don't know about history to this point; but the world would be safer now, I think, today, if no one had ever used atomic weapons in war, and the idea was not considered suitable for polite discussion.

So firebombing would be a perfectly acceptable tactic, then?

I am reminded of one of the medieval popes who banned the use of crossbows against Christians because it was too 'horrific' a weapon to use against 'civilized' people.

I don't recall a single nuke being used in Vietnam, and none have been used in Iraq, but those wars are still messing people up pretty well. It's not clear to me how killing lots of people all at once in a sudden flash is better than killing them slowly and agonizingly with napalm, or incendiary bombs, or machine guns, or crushed beneath tank treads, or rusty bayonets.

Mayhap there's a form of cognitive bias lurking here to be overcome?