Steven Metz, SSI, 22 Dec 06: Learning from Iraq: Counterinsurgency in American Strategy
...Where does Iraq go from here? At this point, the best feasible outcome is, as Ambassador Dennis Ross describes it, "a central government with limited powers; provincial governments with extensive autonomy; sharing of oil revenue; and, at the local level, some rough form of representation and tolerance for minorities". Equally likely is sustained mayhem which eventually leads the government to settle with the insurgents, potentially giving them control of all or part of the Sunni triangle or at least some degree of political influence. It is possible, though, that the insurgents may provoke the government into a draconian response which might, in turn, lead to intervention by other predominantly Sunni Arab states, thus turning Iraq’s civil war into an international one. Either may result in a weak central government, dominated by corruption, with criminal gangs and sectarian militias wielding great influence, or a new authoritarian strong man. Sustaining a multiethnic and multisectarian democracy in the face of mounting sectarian war may be impossible. Outside forces, as Fareed Zakaria notes, can do little to stop a full-blown civil war until its energy is expended. Division of the country into three parts may be inevitable with continued conflict in areas of sectarian overlap, particularly Baghdad and Mosul.

But whether Iraq ultimately turns into a success or failure, it is invaluable as illumination for American strategy. If it is a unique occurrence, then once it is settled, the U.S. military can return to its old, conventionally-focused trajectory of transformation. But if Iraq is a portent of the future, if protracted, ambiguous, irregular conflicts that are cross-cultural, and psychologically complex are to be the primary mission of the future American military (and the other, equally important parts of the U.S. security organization), then serious change must begin.