I don't believe Syria is in any position to be a threat and as for Russia they couldn't even handle their internal problems. I don't think that either is a deterrent to our support.
LOL! No, they certainly do not have a very good position sandwiched in between Israel and the US army, but they definitely have been a nuisance in Iraq and there is a very good possibility that they have Saddam's weapons and in that case they could be a threat if they ever felt like committing suicide, but you are right I do not think they will act unless many act with them.
My only question about Syria was does Russia have a pack to protect them in case of war, though I was more interested in Iran.
As for Russia, the bear might be weak and ill but she still has very sharp claws and the US will never seek direct confrontation, just because of the harm that could be done to our population.