The more things change, the more they stay the same

[Rhydderch Hael]

...The Russians, while were technically not at war with Japan at the time, were NOT neutral in any sense of the word, and they were definately NOT afraid of Japan in 1944. In '44, they were not afraid of anybody.

Nothing exists in a vacuum. I suspect that the dangling fate of China factored heavily into the strategy. If the Russians threw their hat into the ring early on, it could have played the Japanese squarely against the Chinese Communist movement instead of the Nationalist Chinese.

Another cute thing about the matter is that the United States would want the USSR to remain neutral in regards to Japan. The last the United States needed was a Soviet takeover of the Far East.

So, in the twisted logic of political diplomacy, the return of the B-29s would have been a bad thing for the U.S., because it would have violated Soviet-Japanese neutrality, which in turn would have given the Soviet Union the impetus to take China, Korea, and likely northern Japan itself.

In a roundabout way, I concede that this validates your point that the bully nature of the USSR allowed it to get away with things. I reinterate my point on the actions and justifications of a neutral nation in regards to the belligerents of a war. Internment by neutrals is nothing new nor the exclusive course of tyrants bent on espionage and thievery.