We're planning to be out of Iraq in 2011. Is that crazy?

Are all U.S. troops really going to be out of Iraq by the end of 2011? Should they be? Will the country fall apart once they're gone? Or should they, can they, make their exit even sooner?

Even as the official focus shifts to the war in Afghanistan, a debate has erupted over the endgame in Iraq. It is universally seen as an endgame; we are getting out. The issue is how quickly, how completely, and, if some troops are left behind, what they should and should not do.

The Status of Forces Agreement, which the U.S. and Iraqi governments signed in November 2008 (in other words, while George W. Bush was still president), is clear: "All U.S. forces are to withdraw from all Iraqi territory, water and airspace no later than the 31^st of December 2011." No ifs, ands, or buts.

Yet last week, during a trip to Washington, Iraqi Prime Minister Nouri al-Maliki told reporters that the deadline could be extended. "If the Iraqi forces required further training and further support," he said, "we shall examine this then at the time, based on the needs of Iraq."

Several American officers and private military analysts have been predicting for a while that Iraq will still need "further training and further support," and that, therefore, the accord will—or at least should—be revised.

Yet earlier this week, Secretary of Defense Robert Gates, asked whether U.S. troops might stay in Iraq beyond the 2011 deadline, replied that, in fact, the withdrawal might be accelerated. And in today's New York Times, Michael Gordon reports on an internal memo by Col. Timothy Reese, a senior U.S. adviser to the Iraqi military, urging American commanders to "declare victory and go home." Internecine strife still exists and will continue for a long time, Reese wrote, but Iraq's security forces are now "good enough" to keep insurgents from toppling the government—and, meanwhile, the continued American presence is only sparking more violence.

So, which is it: We need to stay longer, we need to leave now, or something in between?

The Reese memo's key insight is that whatever the state of Iraq at the moment, it isn't going to change, certainly not as a result of anything the United States says or does. We've lost nearly all our leverage over Iraqi politics—its tendency toward rule-by-strongman, its Stalinist military, its ethnic tensions, aggravated by the Kurds' secessionist impulses—and there's little we can do at this point to gain it back. Maliki recently gave a cold shoulder to Vice President Joe Biden during the latter's visit to Baghdad. The Iraqi military is imposing restrictions on U.S. troop movements. We're leaving ourselves vulnerable with little power to improve our position.

Yet Reese's main weakness is that he fails even to address the argument (it may or may not be true, but he needs at least to address it) that Iraq's tensions have calmed to the point that its own security forces can handle them only because of the U.S. military's presence and its threat of hammer blows if some insurgent group starts to get out of control.

The dynamics of the impending troop withdrawal were played out last year in a war game—called "Joint Urban Warrior 2008"—co-sponsored by the U.S. Marine Corps and Joint Forces Command. It was a huge "tabletop" exercise, involving more than 350 people from various countries, supervised by a general officer and attended by Pentagon brass.