Obama has done OK on national issue, but on international issues, he has been a disaster. Syria's genocide will eventually haunt his reputation like Rwanda attaches to Clinton's reputation. A single missile could have taken out Assad when he crossed the "red line" that he was toothlessly threatened not to cross.
He and mouthpiece Kerry wagging their fingers at Putin will of course accomplish nothing. Assad will kill another 100,000 Syrians and Europe will just get another millions Syrian refugees, as there will be no one left to fight Assad but DAISH/ISIL.
Stinger missiles could drive the Russians home in a hurry, just as their use in Afghanistan drove them out - the Russians couldn't bear to lose all their MIGs. The missiles could even be controlled by USA "advisors." (There are always secret USA operatives in these situations.) But that won't happen. If the Europeans weren't so paralyzed and cowardly, they might do something - after all, the are getting all the Syrians that Assad isn't successfully killing.
The USA doesn't have to get involved in another mid-east quagmire - just kill Assad (State Dept. mouthpieces can always come up with a legal justification), or arm the rebels.