All that really happens after you read Michael O'Hanlon's efforts to elaborate on the meaning of "Brookings Benchmarks" is that this business of handing out scores (zero! one half! one!) on eleven separate metrics and then adding them up is fundamentally silly. O'Hanlon is trying to introduce a spurious sense of precision to an inherently subjective judgment. Try to ask a coherent question like "is there a broadly based government that enjoys legitimacy across sectarian divides for us to support in Iraq?" and the answer is clearly "no."
O'Hanlon concedes as much, but counters that it's not hopeless to think that such a government might emerge if we keep sticking around and trying to cajole them. I would counter that, on the one hand, hope is not a plan and, on the other hand, that there's nothing stopping us from "hoping for the best" in a withdrawal scenario. The tendency in the U.S. policy debate has been to assess dovish options in terms of worst-case scenarios (regional war! genocide! al-qaeda base!) and hawkish options in terms of best-case scenarios (reconciliation! a new democracy!) but this is completely arbitrary. It's not clear that the presence of a large U.S. military force in Iraq alters the incentives facing Iraqi political actors in favor of reconciliation.
The entire "benchmarks" concept, as was remarked to me by a wise man at lunch yesterday, is an artifact of a particular moment in American politics. Specifically, the Iraq Study Group put together by Baker, Hamilton, and their staffs. Benchmarks were intended to be part of a process by which political consensus in the United States was rebuilt around a policy that didn't mandate a timeline for withdrawal, but did contain an exit mechanism that prevented the ISG proposal from becoming a an open-ended commitment.
I wasn't a fan of the ISG's attempted political intervention, but the proposal was put together by smart people who devised a politically reasonable effort to achieve what they were trying to achieve. At this point, however, all that was a very long time ago and it doesn't make sense to let one specific element of their proposal -- "benchmarks" -- keep stalking the op-ed pages like a zombie. The real work in O'Hanlon's proposal about Iraq is in the analytical framework which says that "mixed results" implies "stay in Iraq." A lot of people believe that's correct, but that's an argument about America's larger strategic posture not an argument about how things are in Iraq. It's always going to be possible to argue that circumstances in Iraq are, in some sense, mixed (and, indeed, O'Hanlon's been arguing just that for years) but dressing it up with numbers doesn't actually add anything to shrugging and remarking that things could be worse.
DoD photo by Staff Sgt. Samuel Bendet, U.S. Air Force