The administration is contemplating disaster partly because it screwed up so many things along the way, but mainly because the invasion was a doomed enterprise from the start. One thing we should have learned from the last century is that people generally detest foreign occupation. Another is that when resistance to occupation flares into full-fledged war or insurgency, the resistance almost always prevails in the end.
Look at the French in Algeria, the Americans in Vietnam, the Israelis in Lebanon (in the 1980s and '90s) or the Soviets in Afghanistan. Each had huge advantages in military might, but all failed.
The administration and its allies learned nothing from this history. So the United States now finds itself in a familiar dilemma. It can withdraw from Iraq, accepting failure and leaving chaos and civil war behind. Or it can stay and keep spending lives and money in a lost cause that has forfeited public support.
Supporters of the war think that's the fault of the public. Former House Republican Leader Tom DeLay complained that what happened in Korea and Vietnam may be happening in Iraq as well: "Our nation lost the will to fight the war."
But you can hardly expect the people to favor a war that is protracted, costly, launched on mistaken premises and so far unsuccessful -- especially when they were told it would be quick and easy. If the administration lacks public support, that's because the public can no longer believe this war will have a happy ending.
On that point, the public is right. The Iraq Study Group can be criticized for not offering a reliable path to victory. But that's like blaming Noah for the flood.