Clive Crook endorses the "grueling option": "a large continuing military commitment, in support of more modest goals." My own sense is as I wrote here:

The rhetoric ranges from John McCain’s “No Surrender” banner to the “End the War Now” absolutism of much of the Democratic base. Yet the substantive issue is almost comically removed from this hyperventilation. Every potential president, Republican or Democrat, would likely inherit more than 100,000 occupying troops in January 2009; every one would be attempting to redeploy them as prudently as possible and to build stronger alliances both in the region and in the world. Every major candidate, moreover, will pledge to use targeted military force against al-Qaeda if necessary; every one is committed to ensuring that Iran will not have a nuclear bomb; every one is committed to an open-ended deployment in Afghanistan and an unbending alliance with Israel. We are fighting over something, to be sure. But it is more a fight over how we define ourselves and over long-term goals than over what is practically to be done on the ground.

The question is: do we want a president slowly withdrawing troops from Iraq to be someone who backed the war in the first place or one who didn't? If we're going to have a de facto empire in the Middle East, wouldn't it be better if it were seen as a reluctant empire, rather than a continuing provocation to Muslims and a recruiting tool for Islamists? There are only three candidates for president who opposed the biggest mistake in American foreign policy since Vietnam when it mattered: Obama, Paul and Kucinich. Only one did so on entirely pragmatic grounds. If we're stuck in Iraq, wouldn't it be better to have a president who can legitimately claim he didn't want to be there in the first place but isn't reflexively opposed to all use of American power? At least that way, there's a small chance we can escape before too long, and a smaller chance that the threat of withdrawal might precipitate some kind of functional government coalition in Baghdad.