Not much about Iraq can be predicted with confidence, but this much can: for the foreseeable future, it will be a messy country with a weak central government, a divided society and regular violence. At worst, as the Iraq Study Group report warns, Iraq will become a failed state racked by civil war that could spill over and engulf several of its neighbors.
Either way, the human, economic, political and military costs of the Iraq war will mount. Scenes of chaos and human misery in Iraq would fuel bitterness against the U.S., first for having initiated the war, then for leaving Iraqis to their terrible fate. The domestic American reaction would be one of relief at being out of a terrible situation, but anger at having been involved in the first place and having invested so much, only to have so little to show for it.
Almost as important as what actually happens in Iraq is how it is understood. One possibility is that people around the region and the world would come to judge Iraq's failure as largely the result of American policy, the product of an ill-advised war inadequately followed up. If this is the case, Iraq would cast a cloud over the U.S. reputation for competence and reliability, and it would last for years. This scenario would create doubts in the minds of America's friends--and, correspondingly, increase the assertiveness of its foes.
An alternative view is that the lion's share of responsibility for what has taken place in Iraq over the past few years belongs to the Iraqis themselves. Under this narrative, the U.S. would be seen as having failed there less for any lack of effort or resolve than for the absence of an effective national partner. This narrative is more likely to take hold if the U.S. publicly sets clear benchmarks for what Iraqis must accomplish regarding political reform and security performance and what they should expect if they come up short.
Whichever story line prevails, the intensity of today's anti-Americanism would fade as Iraq recedes from center stage. The domestic American reaction may persist somewhat longer, however. There is the possibility of an Iraq syndrome, akin to the reaction that followed the U.S. involvement in Vietnam a generation ago. That defeat led Americans and their representatives to be wary of new overseas undertakings.
But it is important not to exaggerate the likely consequences of Iraq's endgame for the U.S. America will remain the world's most powerful country regardless of how Iraq turns out and how much U.S. foreign policy is blamed for it. The U.S. will continue to enjoy a benign international context in which it faces no great power rival, as it did throughout the cold war and as great powers have traditionally done throughout history. And ironically, the winding down of the U.S. involvement in Iraq will have a salutary effect--namely, it will slow the draw on American economic, diplomatic and military resources, all of which are in dire need of replenishment.