Don’t buy it. The US bombed the ever living shit out of Japan in the weeks preceding Hiroshima and Nagasaki. The Japanese would have surrendered, however they refused as their emperor would have been executed. It has to be kept in mind that killing the emperor would be the equivalent of killing a modern day reincarnation of Jesus Christ.
The US ended up allowing him to live, AFTER, dropping the bombs. Truman, and more importantly, his generals had their new toy and he wanted to play with it. Simple as.
I can provide links backing up my statements if you’d like, I’m on mobile right now so I can’t.
I’d like to clarify I’m not anti-US, I’m just stating the facts.