Let's see,..
Egypt: overthrow a military dictator so that radical Islamists can be "democratically" elected, causing no end of problems in the region.
Lybia: Overthrow a military dictator so that radical Islamists can be "democratically" elected, causing no end of problems in the region.
Syria,.. how will this be any different?
It's a civil war. Like all civil wars, the human toll on non-combatants is very high. Historically outside nations get involved in civil wars or not based on national priorities, as viewed by those nations' leaders, not to save non-combatants. Our compelling national interest in Syria is our treaties with, and historic protection of, the state of Israel. Syria's export and sponsorship of terrorism could be considered a compelling interest. In either case, allowing the war to string out and exhaust both sides is probably the best answer, from a national perspective. This would SUCK for everybody living in Syria, but the rest of the region would be at least as well, and probably better off.