Re: Japan: the more complex and tenable version of that theory is the "Racing the Enemy" one I mentioned, after the monograph of the same name (As an aside, one of the review quotes on that page is from John Dolan himself). I've not read it, but my understanding is that it can be summarized as follows: The rout of the Kwantung Army was certainly demoralizing to Japan, but not decisive in itself since Japan was by that point already beaten by every reasonable metric. The surrender was delayed by the refusal of the Japanese leadership to face the reality of their situation. They could see the growing fissure between the USSR and the Western Allies, and their last, desperate hope was to exploit this. They gambled that the USSR, with whom they had a non-aggression pact, would want to prevent an American occupation of Japan, and to that end might wish to broker a negotiated settlement between the two which preserved Japan's independence. The invasion of Manchuria exposed this for the delusion it was and confirmed that the Soviets were committed to Potsdam. At this point a critical mass of the Japanese leadership finally accepted that they were out of options, and surrendered unconditionally.