The crackdown has provoked a serious backlash from Sunni leaders. Many are now calling for an autonomous region—which is legal under the Iraqi Constitution—that could include the three provinces of Salahuddin, Nineveh, and Anbar, the last of which is thought to be sitting on massive oil and gas fields. In response, Prime Minister Maliki and other Iraqi officials have criticized the move as an attempt to weaken the central government.

If an autonomous Sunni region is established, Iraq would face a de facto split along sectarian lines. And that might tempt Shiite Iranian leaders and the Sunni rulers of Saudi Arabia to ramp up their support for their respective communities in Iraq. A former senior Iraqi official, who asked not to be identified because of the sensitivity of the issue, says he has seen documents indicating that the Saudi government has begun funding Sunni leaders to push for an autonomous region.

Any attempt by the Saudis to increase their influence will not sit well with Iran, which has deep ties with the Iraqi government as well as militant leaders like Sadr. The depth of their influence was on display three weeks ago: the same day that U.S. Defense Secretary Leon Panetta addressed the Senate Armed Services Committee about the readiness of Iraqi troops, the head of the Iraqi Army, Babakir Zebari, was being feted like a royal in Tehran. Zebari, who has made headlines in the past by announcing that American troops should stay in Iraq until 2020, seemed to be hedging his bets. He met with Iranian President Mahmoud Ahmadinejad during the trip, as well as with top commanders of the Revolutionary Guards.

Critics say the White House had a chance to curb Iranian influence but was too busy looking for an exit.