>>3609320 (OP)If germany was communist then the soviets would have most likely successfully invaded poland and reoccupied them.
The soviets would most likely give germany land in the danzig corridor after conquering poland to reconnect their lands and become closely allied with germany, even though the soviets and communist germans would have a lot of disagreements with eachother (as leftists do) they would realize that they have to be allied since they would be the only two communist regimes in europe, and them infighting would make it easier for the capitalist western powers to beat them
Even though the former entente nations of italy, france, and britain were exhausted after ww1 and didnt want future conflict, they would remain much more armed and mobilized and have their military doctrine be much more modern and up to pace, france especially would be a lot better militarily by 1939 than they were in our timeline as they would be prepared for conflict with the communists unlike in our timeline where they thought there wouldn't be war with hitler.
Mussolini would still likely rise to power in italy after the war, possibly even easier than in our timeline as he could use the stronger communist presence in europe for more effective fear based propaganda. If mussolini chooses to invade ethiopia, britain, france, and america would likely not protest it as they wouldn't want to isolate an ally against communism.
There would be a similar stance against japan, where the allies wouldnt care that much about what they did in china as they were atleast staunchly anti communist in their ideology.
Some time in the late 30's or early 40's WW2 would likely start between the capitalist western powers of britain, france, and italy (as well as many minor democratic nations) on one side and germany and the soviets on the other. The communist alliance would win in mainland europe and occupy it due to sheer numbers in both manpower and industry, but they wouldnt be able to do shit against the british mainland or any of the colonies held by europe. The soviet navy was always shit compared to the west and for germany, any remnants of their imperial fleet was destroyed or captured after ww1 preventing the communists from using it. The allies wouldnt be able to take back mainland europe but the communists wouldnt be able to touch britain, america, or any of the colonies.
After the war is over the necessity for an alliance between germany and the soviets would be gone and they would have their own split diplomatically, with a chance for war or tense relations between the two in the coming future.