That's basically what was done the whole Cold War. USA goes to Vietnam --> USSR supports the other fraction with weapons etc. USSR goes to Afghanistan --> USA s

That's basically what was done the whole Cold War. USA goes to Vietnam --> USSR supports the other fraction with weapons etc. USSR goes to Afghanistan --> USA supports the Afghans etc. Having Cold War situations again isn't desirable of course but it's kind of battle tested to not lead to further, direct, escalations.