I know this very well. The US was late in a sense to the European theater, but the most substantial contribution of the US was lend-lease in any case. It's of course inaccurate to say that the US was the primary contributor to the European Theatre (that was probably the USSR), but the American contribution shouldn't be understated, either.
Japan was absolutely not going to surrender following the atomic bombs, unless you consider a conditional surrender in which they would keep all their colonial assets something even close to tolerable. The idea that the Soviet invasion of Manchuria was at all a threat to the Japanese is laughable; the Kwantung Army was a hollow shell with most of it moved back to the home isles, which was why the USSR had such an easy time there, and the Soviets had essentially no capability to accomplish an amphibious invasion.
It's true that Japan had already been 'defeated', but the dysfunction of its military and government meant that the sensible option was impossible to accomplish because those who tried would immediately be susceptible to coups from ultra-nationalist factions. Which in fact nearly happened even after the bombs were dropped and the surrender decision was made.
>...Japan would never have surrendered so quickly without use of the atomic bomb...
This is absolutely true, and the statement made by the Emperor directly refers to the bombs. The only alternative story is the Soviet invasion of Manchuria, but not only was that not a plausible threat to the home isles, but during Prime Minister's meeting with the Emperor in which the PM recommended unconditional surrender, he mentioned the bombs and (I don't think, IIRC) the Soviet invasion.
>...victory would have required a bloody invasion of the Japanese mainland, costing hundreds of thousands of lives.
I don't know of anyone who disputes that Operation Downfall would have been a bloody affair that would have killed this amount, if not more.
Edit: I just realized that somebody else already posted a bunch of what I wrote.
Japan was absolutely not going to surrender following the atomic bombs, unless you consider a conditional surrender in which they would keep all their colonial assets something even close to tolerable. The idea that the Soviet invasion of Manchuria was at all a threat to the Japanese is laughable; the Kwantung Army was a hollow shell with most of it moved back to the home isles, which was why the USSR had such an easy time there, and the Soviets had essentially no capability to accomplish an amphibious invasion.
It's true that Japan had already been 'defeated', but the dysfunction of its military and government meant that the sensible option was impossible to accomplish because those who tried would immediately be susceptible to coups from ultra-nationalist factions. Which in fact nearly happened even after the bombs were dropped and the surrender decision was made.
>...Japan would never have surrendered so quickly without use of the atomic bomb...
This is absolutely true, and the statement made by the Emperor directly refers to the bombs. The only alternative story is the Soviet invasion of Manchuria, but not only was that not a plausible threat to the home isles, but during Prime Minister's meeting with the Emperor in which the PM recommended unconditional surrender, he mentioned the bombs and (I don't think, IIRC) the Soviet invasion.
>...victory would have required a bloody invasion of the Japanese mainland, costing hundreds of thousands of lives.
I don't know of anyone who disputes that Operation Downfall would have been a bloody affair that would have killed this amount, if not more.
Edit: I just realized that somebody else already posted a bunch of what I wrote.