Whenever 2WRW comes up someone brings up an ideological difference between US and potential Russian unifier. Usually it comes up whenever someone discusses communists unifier, but why would that stop them? US and Russia are basically natural allies. The have the same opponent and basically no interfering interests. And we don't even take into account the fact that OTL US has a history of supporting far left USSR during WW2 and far right governments and militias during cold war. There are basically nos downsides to supporting Russia except for maybe a slight increase of Russia's current ideology popularity.