This came up in my diavlog debate on Iraq with Jon Chait, but I find it striking how much the non-demagogic arguments in favor of staying in Iraq sound like arguments in favor of leaving. You get things like Anthony Cordesman's much-discussed tenuous case for strategic patience in Iraq which presents what is, I think, an excellent analysis of the situation followed by what struck me as the slightly bizarre conclusion that we ought to basically just hold on or hope for the best. Or here, Fred Kaplan describes a conversation with "Stephen Biddle, a military analyst at the Council on Foreign Relations, is a key proponent of the patchwork-quilt strategy." What does Biddle think? Well:
Biddle also said (again, expressing his personal view) that the strategy in Iraq would require the presence of roughly 100,000 American troops for 20 years—and that, even so, it would be a "long-shot gamble."
Kaplan gets at some of this, but if your analysis is that we should accept a "long-shot gamble" that entails 100,000 American troop serving in Iraq until 2027 then you owe us some kind of explanation of what the payoff is supposed to be. The cost of doing what Biddle's analysis suggests is necessary would be enormous. The benefits, meanwhile, don't seem especially high even if you ignore the "long-shot" nature of the odds. Plug the odds in, and the whole proposition looks ridiculous.
I respect Biddle enormously, and think his argument against a middle path in Iraq is absolutely solid. His analysis of what staying would entail also seems solid. I just can't understand why he doesn't see that the obvious upshot of his analysis is that we should leave. To conclude anything else it seems to me you'd need to put a near-infinite value on the prospect of salvaging something to label "success" in Iraq.