Iraq: Big Picture
I worry that the heavily political discussions of the war supplemental fight have a tendency to distract from the actual strategic question of withdrawal. That, of course, has more than a little to do with the alleged strategic purpose of maintaining a large US military presence in Iraq. Initially, the objective was the establishment of democracy. Later it became preventing Iraq from slipping into a state of civil war. Then it became preventing Iraq from slipping into a "full-blown" civil war or some similar formulation. Now, we're seeking to improve the security situation, especially in Baghdad but also elsewhere insofar as possible.
It's worth noting that throughout this, the US has always had the option of simply choosing sides and trying to use the obviously considerable resources of the American military to assist some faction or other in defeating its adversaries. We have, however, consistently flirted with doing so on behalf of the Teheran-linked Shiite exile parties that provided the main source of pro-collaboration sentiment during the early days of the occupation, only to eventually (and correctly) reject this path as essentially pointless and immoral.
We keep flirting with it, however, because such a policy would have the advantage of offering the continuation of the military presence a coherent objective. Without it, we have a mishmash. The operation is not in support of any of Iraq's factions, but in support of political reconciliation amongst the factions. Not, however, in support of an actually existing political reconciliation that can be expedited through third-party enforcement and foreign technical expertise and material assistance. Rather, in support of a vague notion of political reconciliation that keeps not materializing. Democrats at the moment are claiming to believe that looming withdrawal will prompt political reconciliation, which I suppose might happen, but what's really certain is that keeping tens of thousands of American soldiers in Iraq won't do it. For the policy of establishing security and thereby achieving reconciliation to make sense, you have to believe that insecurity is exogamous to the conflict in a way that keeps derailing the political situation off an underlying pro-reconciliation track.
There isn't, however, any reason to believe this is true.
Because its truth is a necessary condition for the policy to make sense, however, we keep getting offered no explanations of why it is, in fact, true. First the dread "foreign fighters," then the Syrians and their inability to perfectly police a 605 kilometer border with Iraq, now the Iranians and their dead IFPs.
But it's still not true. Not only has their even been any reason to believe that foreigners have been a numerically significant element in the violence, there's also nothing the US can do to prevent Iraq's neighbors from attempting to advance their interests there. Most important of all, there's no reason to see an underlying pro-reconciliation dynamic waiting to blossom just around the corner. One can debate whether or not the absence of such a dynamic has always been the reality of Iraq or whether it's something that emerged in response to earlier Bush administration policy mistakes. The presence of an underlying pro-conflict political dynamic has been perfectly clear since at least late 2004 when Sunni Arabs rejected the whole thing as illegitmate and the Kurdish parties formed a consolidated bloc on a pro-independence platform.
This is the issue and it will always be the issue. The US Army and Marine Corps can, clearly, impact the level of violence, but they can't alter the fundamental trends. They've been given a mandate they can't achieve because it's not the sort of thing soldiers can do. So the soldiers are doing what they can do, which is nice, but it's not going to achieve any objectives in Iraq. So the objectives will keep shifting in an apparently endless search for ways to rationalize the continuation of the war since the war, as such, has evidently become a more important cause than any particular goals the war might possibly achieve.