The question is twofold but the latter leads into the former: WI, instead of Stalin, it was Zinov'ev and/or Kamyenyev who rise to power, saving the USSR from the formers' purges, tyranny, &c.; could Kamyenyev and/or Zinov'ev then be able to, or willing to, fight the fascist Imperial Japanese and Nazi Germany before the OTL WWII broke out in Europe, in a two front war?
If the Soviets used Hitler's Remilitarization of Rhineland, coupled with the Nazi Government's appalling treatment of anyone who wasn't an "Aryan" in their now expanding domain (not to mention the Western Allies' complete lack of action against the Nazis, or the Fascist Italians in Ethiopia, or the Imperial Japanese in their growing territory in the Pacific), as justification for an invasion of Germany, would France, the USA or the UK do anything substantial, or even be able to?
As for where the Chinese come in, they were, and are, a very large country with incredible potential, yet they were too far behind to stop the Empire of Japan on their own. The Soviets would want, probably even need, an ally, or at least a pacified buffer, in East Asia for several reasons: They would want to relive direct pressure on themselves in Siberia, which China could certainly help with with its immense population; they could tip the scales in the post-war world in their favour with much greater ease than in OTL with a friendly China; and China's eventual rise to a world power would in any case be inevitable, so they would want them to at least be on cordial terms with the USSR. Most crucially, perhaps, is that the Chinese could, as in OTL, eventually have a Communist revolution of their own, and, given a more successful, powerful, popular and better USSR (one without Stalin), it could much more likely avoid the Sino-Soviet Split.
China could also benefit from the Soviets: It desperately needed to modernize, and not just its military. While the USA and the UK did provide some aid to the Chinese during WWII (as did the Nazis for a time), to be honest this was remarkably and irrationally limited, IMHO frankly because most of the West was an extremely racist cultural area then (they refused to even treat their WWI allies, the Japanese, fairly as equals during the Paris Peace Conference or in the League of Nations, for example, clearly due to racism); unlike the other Western powers, the Soviets were explicitly anti-racist, and their basic ideology, Communism, had growing support among the oppressed colonized peoples of the world: Therefore, it seems China's natural ally would have been the USSR, and visa versa.
Thoughts?
If the Soviets used Hitler's Remilitarization of Rhineland, coupled with the Nazi Government's appalling treatment of anyone who wasn't an "Aryan" in their now expanding domain (not to mention the Western Allies' complete lack of action against the Nazis, or the Fascist Italians in Ethiopia, or the Imperial Japanese in their growing territory in the Pacific), as justification for an invasion of Germany, would France, the USA or the UK do anything substantial, or even be able to?
As for where the Chinese come in, they were, and are, a very large country with incredible potential, yet they were too far behind to stop the Empire of Japan on their own. The Soviets would want, probably even need, an ally, or at least a pacified buffer, in East Asia for several reasons: They would want to relive direct pressure on themselves in Siberia, which China could certainly help with with its immense population; they could tip the scales in the post-war world in their favour with much greater ease than in OTL with a friendly China; and China's eventual rise to a world power would in any case be inevitable, so they would want them to at least be on cordial terms with the USSR. Most crucially, perhaps, is that the Chinese could, as in OTL, eventually have a Communist revolution of their own, and, given a more successful, powerful, popular and better USSR (one without Stalin), it could much more likely avoid the Sino-Soviet Split.
China could also benefit from the Soviets: It desperately needed to modernize, and not just its military. While the USA and the UK did provide some aid to the Chinese during WWII (as did the Nazis for a time), to be honest this was remarkably and irrationally limited, IMHO frankly because most of the West was an extremely racist cultural area then (they refused to even treat their WWI allies, the Japanese, fairly as equals during the Paris Peace Conference or in the League of Nations, for example, clearly due to racism); unlike the other Western powers, the Soviets were explicitly anti-racist, and their basic ideology, Communism, had growing support among the oppressed colonized peoples of the world: Therefore, it seems China's natural ally would have been the USSR, and visa versa.
Thoughts?
about the KMT. So, for this this hypothetical WWII Sino-Soviet Alliance to work from the Chinese side, I believe it is essential that Chen Duxiu and later probably also Mao receive far greater support from the USSR as early as possible (and that Chen and Mao cooperate together, which I think would be possible given the ATL's circumstances). I don't think Wang Jingwei is a good choice, at least for long, being that in OTL he turned into an Anti-Communist and a fascist collaborator; nonetheless, if Wang hadn't gone to Europe, things could have turned out quite differently anyway.