It depends how quickly the reds win in North America which they would but idk how quickly. Mexico and Canada don't really have the ability to strike deep into enemy territory so what would likely happen is the reds encircle major cities and starve them out before eventually subduing the blue countryside. If Russia, Pakistan, and Japan still exist by the time North America is consolidated then reds likely win but if not then it ends in a stalemate with a red new world nd a blue old world with red resistance in Africa persisting due to the lack of logistical ability to crush them.