the first bomb was dropped on 6 August, the Soviet Union declared war on the 8th. But contrary to American expectations and post-war claims, the author’s diligent research in the Japanese sources demonstrates conclusively that it was the Soviet declaration of war, not the atomic bombs, that forced the Japanese to surrender unconditionally.
Geoffrey Jukes review Racing the enemy: Stalin, Truman, and the surrender of Japan by Tsuyoshi Hasegawa
Thanks for this!