There are about 10 large tribal federations in central Iraq, but there are hundreds of subgroups, each with its own sheik. He is the leader of the people, and in return for his services -- mediation, arbitration, attracting government services to the tribal area -- he is respected and obeyed.
New efforts ought to be made to persuade the sheiks to assert their influence and help keep the peace. The easiest would simply be to hire the sheiks and their tribesmen -- putting them on salaries and allowing them to spread the wealth among their people. In addition, sheiks in areas where coalition soldiers and oil pipelines are coming under frequent attacks should be told that the only way their tribes can receive luxuries -- extra government services, construction aid, easy access to senior officials in Baghdad %u2014 is by making sure that there are no attacks against coalition soldiers in their domain.
If a sheik refused to cooperate, not only could his perks be withheld, they could be given to a neighboring sheik. This would eventually pit the uncooperative sheik against his own tribesmen, who would see that he was not serving their interests. If this weren't enough to get the sheik into line, it wouldn't be too difficult for the coalition to enact 'regime change' on a small scale: almost every tribal leader has rivals within the group who covet his position.
... Amatzia Baram is professor of Middle Eastern History at the University of Haifa in Israel and a senior fellow at the United States Institute of Peace.
I doubt tribes are quite so easy to manipulate, but this is a concrete suggestion. It sounds very British, and somewhat reminescent of US Special Forces activities in Afghanistan.