@lain The bombs, to me, seemed like more like giving Hirohito an excuse. The Japanese people had it drilled into their heads for generations to defend the home islands to the last man and if Hirohito just gave up after the US started winning, he'd be overthrown by warhawks. It took something capable of wiping out an entire nation to get Japanese leadership to step back and take a critical look.
Hell, even with the bombs, a small group of military officers tried to overthrow him anyway.