[greedo]

Yeah, that's the other main argument that we'll never have a definitive answer to. Maybe in 300 years we'll have enough distance to evaluate the evidence without all the cultural biases and baggage, but I doubt it. Every time I read more info about the Manhattan Project and US nuclear policy in the 1950s, my opinion changes. And then when you read about how Truman acted AFTER the war in regards to nuclear weapons employment, I can easily understand that he was going to use nukes no matter what.

Japan's political environment during the war was incredibly complex, and trying to view their rationale and motivation through a Western lens is very dangerous. And I don't think the Soviets were anywhere close to an imminent invasion of the Home Islands. I don't think they had the appetite for doing more than grabbling the Kuriles and Sakhalin Island, instead preferring to let the US suffer the casualties.

While the Soviet declaration of war surely had some impact, the Emperor said there were three primary factors in his decision to accept the Potsdam conditions; his lack of confidence in Ketsu Go plans to defend Kyushu. The increasing devastation caused by the conventional and nuclear bombing campaigns, and finally, concern about the "domestic situation" meaning internal revolt. Later in private letters he referred to Nippon's deficiency in science, meaning a lack of nuclear weaponry. Hirohito and PM Suzuki realized that with nuclear weapons, the US didn't need to invade Japan.