"....Unfortunately, the US didn't take advantage of the opportunity to withdraw during 2005. Decision makers mistook the controlled chaos enabled by the use of militias for progress towards their maximal goals in the country. That illusion officially ended with the attack on the Samara shrine (a form of social system disruption, likely a coup de grace by Zarqawi). After that event, the fragile structure of the system flew out of control as Shiite militias began to ethnically cleanse Sunnis. "The US is now caught between the militias and the guerrillas and the situation will deteriorate quickly. "Here's a likely scenario for how this will play out: deeper entrenchment within US bases (to limit casualties) and pledges of neutrality (Rumsfeld) will prove hollow. Ongoing ethnic slaughter will force US intervention to curtail the militias. Inevitably, this will increase tensions with the militias and quickly spin out of control. Military and police units sent to confront the militias will melt down (again), due to conflicting loyalties. Several large battles with militias will drive up US casualties sharply. Supply lines to US bases from Kuwait will be cut. Protesters will march on US bases to demand a withdrawal. Oil production via the south will be cut (again), bringing Iraqi oil exports to a halt. Meanwhile, the government will continue its ineffectual debate within the green zone, as irrelevant to the reality on the ground in the country as ever. Unable to function in the mounting chaos and facing a collapse in public support for the war, the US military will be forced to withdraw in haste. It will be ugly. "UPDATE: After I wrote this, there was news that the US intervened by attacking a gathering point for Shiite militias in Baghdad. An Imam was killed along with 16 others. There was also a raid on an Interior Ministry prison (Badr). The scenario begins..." - - - John Robb