[samadams2000]

More importantly the BOMB was a message that instantly said, WE BEAT YOU..and THE WAR IS OVER.

[Fraxinus]

One thing that irritates me about many air-power advocates is that they leave the impression that the A-bombs, by them selves, caused Japan to surrender. As this article makes clear the Japanese high command knew that an invasion was planned. Also occurring in roughly the same time period were Soviet invasions of Manchuria, fire bombings of many Japanese cities, and the 5th(?) fleet was destroying anything along the east coast that was judged worthy of sending in a sortie.

I think it unlikely at best that any one of these activities in isolation would have caused the Japanese to surrender.