When to Leave Iraq, Fun With Circular Logic

I'm not sure if this is profound or merely amusing. Cenk Uygur in the Huffington Post writes The Insurgents Will Wait Us Out No Matter What -- They Live There!.

The administration makes the claim that having a time table would allow the insurgents to wait us out. Ok, I can actually see some logic in that, but it does beg the question of what the victory conditions are? If the violence were to stop, would that be enough? Well then if the insurgents really wanted to game the system why not stop the attacks for a few months, have the Americans leave and then start up attacking the new government? So clearly the end of violence isn't a good exit criteria, so what is?

I guess to put in Bush terms, "figuring out when to stop occupying a nation is hard".