Tribes in Constitution

Thanks to RFE-RL, I learn of an Iraqi constitutional provision committing the state to the revival of tribal confederations. Somebody fill me in - why are we doing this? Is it an attempt to get tribal leaders to support the political process so there will be at least some Sunni representation? If so, it seems problematic, as the tribal leaders are threatening to boycott unless language is struck stipulating that tribal practices must be "in harmony with religion, law, and noble human values."

(Cross-posted to Liberals Against Terrorism.)