I do find most people assume the west will "win" by default, but the author hinted that is not certain. I think a stalemate and a cold war steriod possible, and honestly, while difficult, a comintern "victory" of sorts not out of the realm of possibility.
The western front wil be harder than OTL for sure, but it also helps the Eastern front just won't be a thing at all.
The soviet german alliance is also poised to be able to threaten asian colonial spheres, from afghanistan to india. The anti colonial nature will also help in terms of popular support from what I can tell to be honest.
Also, I wonder Japan... They may do a sort of gentleman pact of sorts with japan, though possibly turn on them later, inviting Japan to attack the Asian colonies nearby and perhaps try and divide up india. Granted I can't see them "ally" with them and risk war with the United States. And uhhh....FDR... well he had a uncomfortable admiration of stalin unfortunately from what I can tell to be honest.