Things are hardly that simple. There are strong arguments that US officials believed Japan was close to surrender before the bombs, and that the US decision was

Things are hardly that simple. There are strong arguments that US officials believed Japan was close to surrender before the bombs, and that the US decision was made as much for its message to the USSR as to guarantee there'd be no need for a ground invasion of Japan. It's been a long time since I looked at it closely but various documentary evidence for such arguments is collected at the museums in Hiroshima and Nagasaki. Whether one finds it all conclusive is up for debate but it's not a cut-and-dried matter.