NATO. vs. USSR vs. PRC
+ real-world basis
+ East vs. West
- in the real-world, China wasn't much of a true contender for the third side
- communism vs. communism could be boring for some
or
Allies vs. Axis vs. Comintern
+ Hearts of Iron 2 basis
+ has both fascism and communism, oh my
- not much real-world basis; it was inevitable that two would gang up on one
- the above is probably unlikely to last for long because Russia is right next to fascist-controlled Europe- at least China and Russia are separated by Siberia
All of this is ignoring things like a cohesive Non-Aligned Movement or a Japanese Empire doing its own thing.
+ real-world basis
+ East vs. West
- in the real-world, China wasn't much of a true contender for the third side
- communism vs. communism could be boring for some
or
Allies vs. Axis vs. Comintern
+ Hearts of Iron 2 basis
+ has both fascism and communism, oh my
- not much real-world basis; it was inevitable that two would gang up on one
- the above is probably unlikely to last for long because Russia is right next to fascist-controlled Europe- at least China and Russia are separated by Siberia
All of this is ignoring things like a cohesive Non-Aligned Movement or a Japanese Empire doing its own thing.