LAURENCE REES: But then, after having dropped nucelar bombs, the Americans allow the Japanese to keep the Emperor. But before the bombs were dropped they were still refusing to say they would permit that. 

AKIRA IRIYE: Right. So I guess there’s a big speculative question of whether the United States might have been willing to let the Japanese keep the Emperor before the bomb was dropped. Truman gives the go ahead to the US Air Force to drop the bomb, I think something like on August 1st. There is a little interval between the declaration at the Potsdam Conference which was something like the 27th July; towards the very end of the month of July. If Truman had sent word that we have this awful bomb that we could drop on you but we will let you keep the Emperor if you surrender right away, would that have worked if the Emperor had been aware of this and had been consulted about it? I think he might have said yes, and many of the civilian leaders would have said yes. The armies would have said no, so the question does come down to whether the Emperor and his advisors and others in the Navy would have been willing to fight the Army.