This is interesting:
The U.S. ambassador to Iraq warned Iraqi politicians Monday they risk a loss of American support if they do not establish a genuine national unity government, saying the United States will not invest its resources in institutions run by sectarians.
U.S. Ambassador Zalmay Khalilzad delivered his blunt warning during a rare press conference after signs that talks on a new government following the December elections were not going well because of sharp differences among the country's Shiite, Sunni Arab and Kurdish political parties.
Failure to establish a unity government that includes a strong role for Sunni Arabs would fail to undermine the Sunni-dominated insurgency and throw into question U.S. plans for a phased withdrawal of the 138,000 American troops here.
The Shiite and Kurds have felt empowered to freeze out the Sunni, knowing that US troops will protect them when the Sunni turn to violence. This is a move to take away that safety blanket and force a hard political choice on the Shiite and Kurds. Now it could turn out they can't unify with the Sunni (or each other) Which means some form of civil war. Which is a war the US Ambassador just said we won't fight.