Looking towards Allawi and a "secular" coalition may not be the answer. AQI and the Sunni insurgents are both dedicated to defeating the U.S. first and foremost. Meanwhile if the U.S. looks as if it is behind the ejection of the UIA and the Maliki government, we may spark an open Shia rebellion from both SCIRI and the Mahdi Army. Iran would feel free to come in heavy on the Shia side. Large parts of the Iraqi Army and Interior Ministry would become untrustworthy, to say the least.

We could very well trade what is mostly a Sunni insurgency now for a much more violent Shia/Sunni insurgency combined with a multisided civil war, with only a tattered secular Iraqi coalition (most of whose constituents have already fled the country) and the Kurds on our side.