It reminds me of what Colonel Cathcart (IIRC) said to Yossarian in Catch 22, that he could go home as long as he liked them. Does it really boil down to that? Does the US just want the Iraqis to like them so much they'll never be a threat again, or at least a puppet government that like them? What ever happened to let them hate us as long as they fear us?
It can't be the oil itself because the Iraqis have alwys sold their oil to everyone anyway. If it is the worry that the Iraqis will sign oil contracts with only Russia and France then that seems to be very similar to the war being all about oil from the start.
No one thinks there are weapons there seriously any more. It will cost too much for the US to pay for restoration, they don't have that kind of money. If they just pull out then if necessary the UN can help later, the US can write a cheque each year for a few billion to give the appearence of helping and then it's all over.
The "can't get out" attitude is not a plan, you don't occupy a country because you can't leave, you do it for strategic reasons. "Seeing it through" also isn't a plan. I think Bush in the long run would do better in the polls by just having the Iraqis wake up tomorrow morning and finding the Americans have left.
I imagine many soldiers would be feeling like this quote from Catch 22:

""Do you know how long a year takes when it's going away?" Dunbar repeated to Clevinger. "This long." He snapped his fingers. "A second ago you were stepping into college with your lungs full of fresh air. Today you're an old man."

"Old?" asked Clevinger with surprise. "What are you talking about?"

"Old."

"I'm not old."

"You're inches away from death every time you go on a mission. How much older can you be at your age? A half minute before that you were stepping into high school, and an unhooked brassiere was as close as you ever hoped to get to Paradise. Only a fifth of a second before that you were a small kid with a ten-week summer vacation that lasted a hundred thousand years and still ended too soon. Zip! They go rocketing by so fast. How the hell else are you ever going to slow down?" Dunbar was almost angry when he finished.

"Well, maybe it is true," Clevinger conceded unwillingly in a subdued tone. "Maybe a long life does have to be filled with many unpleasant conditions if it's to seem long. But in that event, who wants one?"

"I do," Dunbar told him.

"Why?" Clevinger asked.

"What else is there?"