This month's National Journal has a piece looking at the nuts and bolts of withdrawal from Iraq--what it would entail, who would stay behind, etc. Most of the piece just recaps the battles in Washington over funding and the like, but these two paragraphs are unnerving:

It's almost impossible for the military to seriously plan for a contingency -- withdrawal -- that the commander-in-chief won't even discuss, Sinnreich noted. "The probability that it would leak to the press is too high, and no one in uniform wants to take that chance," he said. "Yet only with deliberate planning will we be able to take some of the sting out of what will surely be seen as a U.S. retreat. My point is, there are defeats -- and then there are defeats."

Knowledgeable Pentagon sources say that some planning for a possible drawdown in Iraq is in the "conceptual" stage, but they concede that the vast majority of the military's energy and effort is focused on implementing the troop surge and Petraeus's counterinsurgency campaign in Baghdad. If the campaign is successful, it will certainly set the conditions for a more orderly withdrawal. Yet some experts recall a similar lack of serious advance planning for "Phase 4" stability operations in Iraq, even as the 2003 invasion loomed.

So let's see. In all probability, the United States is going to draw down troops from Iraq sooner or later, regardless of whether the surge ends up pacifying Baghdad or not (likely not). Military experts all agree that pulling out could prove to be the most difficult and treacherous phase of the entire war. But the Pentagon can't really plan for withdrawal because the president doesn't want to discuss it. That's... more than a little frightening.