This is an insightful comment. The Japanese economy was virtually wrecked by early 1945 by the US submarine offensive. The strategic bombing offensive had not really begun to affect what little was left of the economy until spring of 1945. But the important thing to note here is that absolutely none of Truman's advisers, even as late as June or July were willing to venture even a guess as to when the Japanese would be forced to lay down their arms because of economic failure. It was essentially irrelevant to the Japanese generals that civilians were starving and the arms industries were withering away.


According to the Emperor's own account in Showa Tenno Dokuhakuroku even he was in favor of prosecuting one final battle in order to obtain more favorable terms as late as June, 1945. Only after a negative report on the progress of the preparations was made to him did he realize the folly of such a course.


'Richard Frank in "Downfall" concluded just the opposite. Although the Japanese ambassador in Moscow was informed of the Soviet declaration of war on August 8, word did not reach Tokyo until about 4:00 AM on August 9, just hours before the Nagasaki bomb was dropped. Frank notes that although the generals had previously said the Soviets must be kept out of the war as a precondition to continue fighting, they now took the view that a Soviet invasion of Manchuria had been inevitable, and almost to a man vowed to continue with the war. The Soviet attack could not have come as much of a surprise to the generals as Japanese intelligence had been reporting a heavy buildup of Soviet forces along the Manchurian border for months. In any case, it was Hirohito who ultimately made the decision to surrender and the evidence indicates he had made that decision days before the Soviet invasion. Additionally, in Showa Tenno Dokuhakuroku, Hirohito mentions his reasons for making the decision to surrender as growing public unrest and the atomic attacks. He mentions the Soviet attack on Manchuria only obliquely. It would seem strange that the Japanese, who, in June and July, were apparently willing to barter Manchuria away if it would keep the Soviets out of the war and persuade them to become intermediaries, would suddenly decide to surrender because Manchuria was being attacked. Frank concludes that the immediate threat of another atomic bomb, perhaps exploded over Tokyo in the next few days, had a much greater impact that the Soviet offensive in Manchuria.



This is where so much confusion over the casualty estimates originated. The original estimates were based on the original intelligence estimates of what Japanese forces would be on hand to oppose Operation Olympic. As the months passed American intelligence continually increased their estimates of the numbers of troops and kamikazes the Japanese would be able to deploy in the defense of Kyushu. Obviously, the more opposing troops and kamikazes, the higher the potential number of casualties. So anyone who wants to make a case for or against the invasion (or use of the bomb) can enhance his argument by picking a casualty figure from early or late in the planning process. Nimitz and King, who had originally supported the invasion of Japan, finally withdrew that support as a result of the increased potential for high casualties.