Waiting for UN approval to hit Syria militarily is a fool's game.
We would have about the number of Iraqi troops ready in order to take action against Syria about this time next year. The problem is if we collapse the Assad regime with airstrikes you end up having several Baathist generals in Syria fighting for power along with Abu Musab al-Suri (a relative of Zarqawi) and the leader of al-Qaeda in Syria vying for power. A failed state in Syria would be pretty bad, if we could free up a few divisions we could deal with the problem.