That's why I have to echo Yglesias' point:
As best I can tell, it's wrong to assume that there's a real fact of the matter as to what it is Obama is planning to do about Iraq when he becomes president. At the moment, he's running for president and would like as wide a swathe as possible of people to believe that he agrees with them.
Of course this very thing is what a lot of people despise about politics - that candidates don't honestly elucidate their positions during the campaign. But that's politics and it isn't going to change just because we might want it to, or because we get angry about it. There are real reasons politicians don't do this - if they did, they would lose. Too bad.
What political thought requires of an informed voter is not just a factual knowledge of what a candidate says and does, but also the ability to think through the factors that might be influencing a candidate when and if he or she eventually does take office.
That goes beyond just looking at who will be advising the candidate in office to thinking about what the actual facts of the situation will be when Obama takes office.
If Obama comes into the White House in January, he is of course going to find an Iraqi system that is far, far more screwed up than has been acknowledged publicly by the Bush Administration. One of the things that will be the most screwed up is the record-keeping - Obama and his people will simply have no reliable way to quickly construct an accurate picture of what is happening in the war zone, especially since Republican operatives are famously unwilling to pass along information and analysis to Democrats when the Dems are taking over from the GOP.
In such a situation, an Obama administration that had committed to having all troops out of Iraq by such-and-such a date would almost certainly immediately begin walking the deadline farther and farther into the future with the explanation that "we didn't realize how far gone the place really was." In other words, the promise would be one that could, under most foreseeable circumstances, be quickly broken by Obama.
Now there is a subtle point that very few people have discussed so far in this election. The Iraq War is currently viewed in the media as primarily an issue for the Democratic base, and that Obama thus should use his position on the war to rally his supporters. But that's backwards. Currently a huge, huge majority of the country opposes the current US campaign in Iraq and wants it to end. However, many of these people are not leftist or even particularly antiwar - they just rightly don't see the point of continuing to fight in Iraq.
When Iraq comes up in the campaign, remember that it is primarily these right-leaning war opponents Obama will be speaking to. We lefties have every right to demand our red meat in this campaign, but we need to be realistic about the fact that it's going to come primarily in the context of other issues.