It's a good idea. If the Axis win the game, they may split up and fight between themselves for the remaining spoils. Same after an Allied victory with SU being in the Allies. In fact the original manual said that the SU could join the Allies or the Axis but after beating the other alliance, they would split up and reborn the Komintern.
In my current game, between me (Rep.Spain) and my ally (the Soviet Union) conquered the whole world. After beating the Axis and Allies, I couldn't resist to edit the game, break the Komintern, reborn the Allies (with me) and DOW the SU...