On Tuesday, David Satterfield, the U.S. State Department's top Iraq advisor, told reporters in Baghdad's Green Zone that the issue of legal immunity for security contractors is becoming a stumbling block in negotiations about a long-term U.S. troop presence in Iraq. Satterfield also said that he believes a deal can be struck by the end of July, but admitted, "The issue of contractors including (foreign) security contractors is a sensitive one, is a significant one."

As Salon's Mark Benjamin and I detailed in an article we wrote last September, the Bush administration has created a system in which security contractors are essentially immune from prosecution both in Iraq and in the U.S. This has angered Iraqis, especially after incidents in which contractors killed apparently unarmed civilians.

The military has become dependent on contractors during the occupation of Iraq, and a continued presence there would be very difficult to maintain without them.