Here's an interesting piece that suggests that the only sensible way out of Iraq would be to admit American failure and ask for help and cooperation from many other nations in stabilizing the country to the degree possible:

Toby Dodge admitted that anyone arguing against immediate withdrawal has to face the “killer question: Why should American troops continue to die when the chances for success are so low?” He offered his answer “with an honest recognition that it doesn’t sound very plausible.” Dodge’s approach would bring the maximum pressure to bear on Iraqi politicians by persuading the region and the world — Iraq’s neighbors, the European Union, the United Nations — to come into the Green Zone, not as tools of American policy but as equal partners in an effort to force a political deal, not unlike the U.N.’s role in creating a government in Afghanistan after the fall of the Taliban. This would imply an American confession of failure. Instead of pursuing more ambitious goals for democracy in the region, the U.S. would offer security guarantees to Iran and Syria in exchange for coöperation. “We then turn to the Iraqi government,” Dodge went on, “and say, ‘You’ve got to reform your government, make it more inclusive, less corrupt, more coherent, less sectarian.’ So the Iraqi government is reconstituted within a multilateral framework where the E.U., the U.N., and the U.S. are all singing from the same hymnbook.”