Russia pulls out, Assad loses, isis/al queda wins or one of their benefactors, Turkey moves in.
C'mon man. Get real.
There are doubtless dozens (hundreds?) of people being paid to "think this through" 24/7/365...
I remember a college history prof, WWII vet, not a lefty said that American history could be summed up in one sentence.
"Oh s***, how the hell did we get into this?"