One enemy at a time. We allied with and armed Stalin's USSR to defeat Nazi Germany.
Should we have done otherwise...???
That’s the trillion dollar question. Are the constant failures of interventionism better than the potential failures of isolationism? As much as I hate being the World’s Policeman (and most of that crap came from Democratic administrations, or neo”conservative” advisers who are glorified militant leftists), that Pandora’s Box was opened years and years ago and there is no closing it. If we must do it, I’d prefer more covert operations rather than massive deployments to the World’s toilets.