After the Hiroshima bomb, the Japanese realized that there was a new dimension to the war, but having lost so many cities already, 67, they considered a couple more wouldn't matter! They deduced, correctly, that there were only a couple of bombs available and were willing to suffer another if needed. Their scientists told them that this was indeed an atomic bomb just like Truman said. When the second, Nagasaki, bomb and the Russians declared war they were still stalemated about surrender.