The attrition body count and capture statistics that come out of MNF-I are astounding and they are never updated by the how many people who are either killed or detained actually were insurgents. The front end numbers give the glimmer of hope if the assumptions on the size of the Sunni Arab insurgencies were anywhere near accurate, as those insurgencies would have suffered 100% to 300% casualties over four years which is a rate usually sufficient to destroy the effectiveness of any network.
But there is a problem that I have often pointed out --- US intelligence and information sorting capacity in Iraq sucks. D-N-I is reporting that over two thirds of all 'security detainees' who are in the US system for at least three days are eventually released due to a lack of evidence of their involvement within the insurgencies and sectarian violence. Even those who are transferred to Iraqi courts experience a 50% release rate, and these individuals have a higher standard of evidence than the rest of the detainee population.