General Discussion
In reply to the discussion: In defense of Harry S. Truman and the decision he had to make. [View all]Bucky
(55,334 posts)The Japanese army and the Big Six knew by the end of that same day that what happened at Hiroshima was an atomic bomb. There were established lines of communication between the US and Japan (through the Swedish embassy in Moscow, if I recall correctly) so that the Japanese could have offered any number of messages to end the carnage before or after Hiroshima. What they had was a political structure that, due to internal dynamics, didn't allow them to surrender.
What is clear from the records of their deliberations is that they were still more worried about Russia invading their homeland than about the a-bomb. I strongly recommend reading Racing the Enemy to get a clear picture of the hows and whys of the surrender and of the cultures in Washington, Tokyo, and Moscow that led up to the two bombings.