Under previous U.S. strategy, the odds for success in Iraq were very poor. The new strategy improves them, but not by very much.
There is some good in the new strategy. Changing the mission of U.S. troops to emphasize population security for Iraqi civilians, for example, is a step in the right direction. So is the replacement of the old, open-ended U.S. commitment with some degree of willingness to make our presence conditional on Iraqi political progress toward reconciliation.
But there are also some important shortcomings. The sustainability of the troop increase, for example, is unclear yet very important. If our troop increase is temporary, insurgents and militias have an incentive to wait us out by hiding their weapons, melting into the civilian population and reemerging as soon as conditions improve for them.
...it is hard to see why vulnerable Iraqi politicians would be willing to take risks for reconciliation without a promise of a continuing U.S. presence to protect them and their constituents if they do. In short, if the U.S. presence is known to be temporary, then so will be any reduction in violence.
Biddle, like nearly every critic of the plan, has a problem with the number of troops being sent, and heavy reliance being placed on unproven Iraqi forces:
Arguably the biggest problem here, though, is the scale of the announced reinforcements. The new troop commitments still leave us well short of the usual rules of thumb for the number of troops needed to pacify a city the size of Baghdad, much less the rest of central Iraq.
To make up the difference will thus require a major contribution by Iraqi forces. The new strategy calls for just this, in the form of some 18 brigades of Iraqi soldiers and police with about 50,000 combatants in all. The competence—and the loyalty—of these combatants, however, is far from certain.
His last point is demonstrated by this article (via Kevin Drum.)
So the new strategy is thus a long shot gamble. The odds are a little less long than before, but only a little. Are the odds too long? There is no objective analytical answer. The issue turns on one’s personal tolerance for risk and cost, and reasonable people will judge the same odds differently. After all, failure in Iraq would do grave damage to U.S. interests—it may be worth a long shot gamble to get even a small chance at averting disaster. But the chance offered us here isn’t very great, while the cost of the gamble in American lives is likely to be heavy. It is not unreasonable to judge that the odds are now too long and the cost too high.
Biddle doesn't say as much, but it's easy (perhaps a little too easy) to characterize his argument as "too little, too late." This is certainly true. Shortly after his piece in Foreign Affairs was published, the Bush administration did in fact begin talking about "oil spots" and "clear and hold." At the same time, they told us executing these plans would require no more troops, and that if the plans succeeded, our troops would likely be coming home within the year. Only now are they willing to admit to us (and possibly themselves) that none of these security "plans" can be carried out without more troops, but there are only 20,000 more to send, and increasing the size of the Army in any responsible way would require not months, but years of effort. The result is a plan that seeks to secure only Baghdad, that places great reliance upon Iraqi troops that have to this point been completely unreliable, and adopts the critical assumption that if Baghdad can be secured, in some way this success will spread out beyond the capital without any further effort or soldiers on our part. It is for these reasons exactly that I and my colleagues here at TWM have decided that the odds are in fact far too long, and not worth what it will cost our soldiers who will attempt to execute this plan.