It is widely considered (at least, I frequently read such opinions) that nuclear bombings of Hiroshima and Nagasaki were one of the biggest factors in Japan surrendering when it did, and not after US invaded Honshu and captured Tokyo. Is that true? What other factors were there, and how much they contributed to it?
The major other "factor" that is argued about is the Soviet declaration of war against Japan and subsequent lightning invasion of Manchuria. That happened at midnight on August 8/9, so it is right in the middle of the atomic bombings (Hiroshima was August 6, Nagasaki was August 9th). It is indisputable that the Japanese thought this was a big deal at the time (and so did the Americans, though they tend to write it out of the "narrative" because emphasizing the atomic bombs is done to justify their use); the question is whether they would have surrendered without the atomic bombings or not.
There is a lot more that could be said, and has been said on here before. Search for "Hasegawa" in the sub search and you'll find many discussions of this, like this one from several years back. (Tsuyoshi Hasegawa's Racing the Enemy is the most respected of the works that puts forward the thesis that the Soviet invasion had at least as much impact on Japanese surrender as the atomic bombings, if not more.)