Iraq and the US have yet to reach consensus on the Status of Forces Agreement (SOFA). Maliki's summary of the sticking point is as follows:

On Saturday, Maliki outlined a somewhat different position. “If Iraqi and American soldiers move in an operation that is pre-agreed by both sides, then they have immunity unless [an American] commits a deliberate crime during the operation.”

“The sticking point,” he said, “is about if the American soldier was not on a mission and commits a crime that is accountable to the Iraqi judicial system, whether small or big. The Iraqi judicial system should have jurisdiction over the American soldier. This is the point of difference.”

Via. As of January 1, 2009, US Forces will be operating in Iraq illegally, so time is of the essence. Furthermore, Maliki has essentially dismissed Britain's presence in the country as extraneous. These developments make the domestic squabbling over whether a timeline is appropriate seem slightly misguided; ultimately, the President may be accountable to other authorities on this issue. Of course, that doesn't mean we can't blame the current stalement on Iran or, alternately, Barack Obama. (Marc Lynch's refutation of the latter here).

Update: New intelligence lends credence to the possibility of Iran acting to stifle SOFA negotiations.