The presence of American troops is what's largely fueling the terrorism-driven Iraqi insurgency in the first place. Announcing in a credible way that we plan to leave -- really leave -- would at least partially draw its fangs.
As long as American troops are around, Iraqi leaders don't have enough incentive to make the hard choices needed to agree on a constitution and train troops to guard their own country. A no-nonsense announcement from the U.S. would force them to get moving.
The military can't keep up its current tempo in Iraq for much longer, and sometime in 2006 a drawdown is probably going to become necessary no matter what. If that's the case, it's better to do it on our own terms instead of waiting to be forced into it.
I think these make a lot of sense. I have two concerns however.
My overriding framework for evaluating any Iraq policy is how it affects the people. No, not our people, the Iraqi people--the folks whose country we invaded. I think that too often the Iraqi people are getting lost in the Iraq debate. Liberals talk about dead American troops and mounting costs. Conservatives talk about all the terrorists we're killing. (And nutjobs talk about how awesome the terrorists killing American troops are). We have a moral obligation to not leave the people in a state of chaos, and unfortunately so far we've been performing miserably in that respect. For liberal hawks like myself, this has been THE most disappointing part of the invasion--that after all of this, we couldn't even guarantee Iraq a future. But I'm not quite ready to give up hope yet--I think there still must be some way that we can, if not "win" in Iraq, avoid a disaster. At this point, however, I'm open to arguments that withdrawing is the best way to help create a better Iraq--if not that we should abandon the project of creating a better Iraq all together.
Of Drum's three arguments, the third is irrelevant to the "people first" framework, and the second argument I just don't think is true. A sudden withdrawal I think is likely to create a panic amongst political leaders in Iraq. MAYBE this will result in them pushing aside silly differences and creating a working government, but somehow I'm skeptical. More likely, the panic will exacerbate pre-existing tensions and make the problem worse, not better. I mean, it's not like liberal values are doing so great in the constitutional process even with--in effect--unlimited time for negotiations. Push comes to shove, and I think everybody becomes a lot more testy and thus a lot more radical.
Whether or not you believe my likely conclusion or Drum's depends a lot on how you evaluate argument one. I'll assume, arguendo, that our troops are the root of most of the current terrorism against us. The question, then, is whether Iraq has passed the "tipping point" where it is so destabilized that it cannot support itself without outside assistance (IE, US troops doing right). After all, even if most of the terrorists are drawing their support right now as resisters against the occupation, it is a bit fanciful to assume that if we leave, they'll quietly disarm and go away. So, if you think that without the aggravating factor of US troops Iraq will be able to right itself, then withdrawal will seem like a good option. If you think that a withdrawal will lead to a power gap that will likely be filled by violent militias and a bloody civil war, then US troops (for all their flaws) become the last bulwark before disaster. Cynic that I am, I believe the latter.
Basically, if liberal withdrawal advocates want to win over liberal hawks to their position, they have to show some methodology by which Iraq won't obliterate itself the minute the US leaves. Barring that, I'll stick with the occupation I know, rather than the Lebanese-style civil war I know even better.