Main question is the degree to which "the insurgency" is irrelevant. Is there enough bad blood, because of all the (continuing) killings, between Shiites and Sunnis that the civil war will continue regardless of the titular "head of al Queda in Iraq"? The only way the new Iraq government can prevent this is to ensure that all the official government forces are perceived as even-handed by the Sunnis---that, is that they are not riddled with Shiite militia. And, as I said, "de-Baathification" will have to be severely curtailed. Reconciliation is the only way.