William Stuntz in The Weekly Standard offers us a classic Green Lantern Theory account of Iraq, urging us to merely try harder in Iraq and demonstrate our implacable resolve to win. D at Lawyers, Guns, and Money takes some of this apart, but perhaps we can dig deeper.
Part of what we see here is a really inept analogy to Abraham Lincoln's late-Civil War statement that "the nation's resources are unexhausted and, we believe, unexhaustable." One thing to say about this is that, obviously, it wasn't true. Any nation's resources are capable of being exausted. Lincoln's point, however, really was to demonstrate implacable resolve. He intended to govern as if it was worth bearing any burden, paying any price, to restore the Confederacy to the Union. But why did Lincoln say that? It wasn't just a tactical gambit, it represented his actual beliefs about the stakes of the war.
Lincoln's view was that the Civil War was, quite literally, a war for the nation's survival. Recognition of the right to seceed would destroy the United States as he understood it, turning it into a loose confederation of quasi-independent states easily subjectable to domination by stronger European powers.
Perhaps his view of that situation was mistaken, but I think it was a credible sort of thing to believe. And, under those circumstances, a maximum resource-commitment to the war effort is a reasonable policy idea.
It just doesn't stike me as credible at all to think that the imposition of a stable American-backed government in Baghdad with effective control over Iraqi territory is a matter of national survival for the United States of America. Indeed, I think that's a crazy thing to believe.
By contrast, most of Iraq's Kurds, Sunni Arabs, and Shiites seem to feel that the maintainance of ethnosectarianly specific military forces is a genuinely crucial matter of near-existential importance to their respective communities. This is a totally non-crazy thing for people to believe. Kurds and Shiites both have, in the very recent past, been subjected to incredibly brutal repression by a Sunni-dominated central government. They, not unreasonably, fear the return of such repression. Sunni Arabs, meanwhile, have an also-not-unreasonable fear that Kurds and Shiites will, in their desire to avoid a return to repression, engage in similar repression.
What's more, unlike the American military, the vast majority of Iraqis can't leave Iraq. Under the circumstances, any effort by the US government to demonstrate "resolve" to outlast the various militias and insurgent groups isn't going to be viewed credibly by anyone. Stuntz analogizes his proposal to poker, and it's not a terrible analogy, it just cuts the wrong way -- doing what he proposes would be like trying to bluff someone who's already gone all in. It's essentially impossible for countries -- even very rich, very technologically advanced and militarily adept countries -- to perpetually occupy foreign territory in the face of determined opposition for precisely this reason. The occupier can leave, and the occupied cannot.
What could break the dynamic in Iraq would be an intra-communal settlement. In principle, major Sunni, Shiite, and Kurdish groups could reach a mutually acceptable agreement about how to organize the country at which point the violence would sharply diminish. Such an agreement would render US forces unnecessary. Meanwhile, absent such an agreement, US forces -- though perhaps keeping a lid on the killing -- are failing to actually solve anything and are doing so at enormous expense.