With that noted, it's worth mentioning that your premise is false in your implication that the choice is either a) occupying Iraq, or b) fighting terrorists here... as though occupying Iraq in any way lessened the probability of needing to fight terrorists here.
It does not.
How many terrorist attacks have Muslim fundamentalists carried out in the U.S. since our invasion of Iraq?
We are winning, and we are safer because of it. If Saddam were still in power, al-Qaeda would be vastly more powerful and influential in the region, our ally Israel would be in even greater peril; and Saddam would by now have achieved success in the weapons program liberals now deny ever existed, but about which thousands of pages of declassified intelligence documents say otherwise. And no matter what that idiot McCain says, we will not be there for another "100 years".