From what I've read, if the present Syrian government falls any time soon, the next one will likely be dominated by the Moslem Brotherhood. If Bush were then to invade, a la Iraq, it will mean more American body bags--I don't think Bush could pull that off.   It's also questionable whether Congress would be so meek this time around. Even Republican majorities know what angry voters can be like--and 1994 isn't so long ago.

Bush is also not in the strongest position at home these days. And a "Wag the Dog" style approach would be too obvious--and result in the whole US being full of Cindy Sheehans.