Brendan Green in comments ads some context to my mild surprise that Stephen Biddle doesn't think the upshot of his views is that we need to leave Iraq:
At APSA last weekend, biddle indicated that his personal view was that we should leave. But for Very Serious reasons, he feels he should maintain that the surge is an intellectually serious longshot (with a 10% chance of success he hazards) for those who think the costs of leaving are unbearable. More fairly, he also wants to cut the ground out from under the middle options, in the hopes that people will draw your obvious conclusion.
That strikes me as a bit of an odd approach. Also: Did Biddle really say that? I'm pretty sure more than one reader of this blog was at APSA.