The fact is, faced with an existential crisis any nuke equipped nation will start lobbing ‘em rather than being destroyed - the US has done it just to hasten an end to a war that would have ended in the US’ favor anyway.
A lot of men were killed in that war, thousands per day. Who knows your father could have been one if they had not done it when they did. 3 members of my family were killed just days before. The war needed to end.
Big difference between that and Ukraine. Japan stated the war with the US. Russia started the war with Ukraine.