Syria has just been proclaimed the culprit in the Lebanese assassination. This could have huge implications. This means Syria has not just the ability but the will to carry out terrorism, making it extremely likely that they are actively supporting the insurgency in Iraq. Of course, any action should await confirmation of such intervention, but in the interim they are already paying a heavy price for their sins in Lebanon. Chances are the UN can get them to capitulate and straighten up through various resolutions.
The sad part here is the invasion in Iraq has failed to have much, if any, intimidation effect on its neighbors. Iran continues to push nuclear weapons, and now Syria could be fuelling the destruction in Iraq. Truly this has been a horribly executed war.