CSIS, 22 Aug 07: Iraq’s Insurgency and Civil Violence: Developments through Late August 2007
....Much of the progress in the fighting came from a rising Sunni tribal resentment and anger against al-Qa’ida and the most extreme elements of the Sunni Islamic extremist movements that had nothing to do with US plans and strategy or the actions of the Iraqi central government. US military officials were able to pursue local alliances with tribal and sectarian groups to fight against al-Qa’ida in Iraq. There were also signs that such alliances could be expanded from Anbar to cover other parts of Northern and Central Iraq and Shi’ite, as well as Sunni tribes. In Taji, the first Shi’ite-Sunni tribal alliance was formed between the 25 local tribes in the area of Anbar.

At the same time, however, some aspects of the Shi’ite extremist threat continued to increase. Many Shi’ite militia elements did “stand down” as a result of the “surge,” and did not clash with US troops. Less violent forms of Shi’ite sectarian cleansing continued, however, and Sunnis continued to be pushed out of mixed areas, including Baghdad. According to one calculation by U.S. military officials, 52% of violence in Iraq was caused by al-Qa’ida and other Sunni insurgent groups, while 48% was due to Shi’ite militias.

Coalition encounters with the Mahdi Army in northeast Baghdad increased, raising tensions between Coalition forces, Muqtada al-Sadr, and the Maliki government. Prime Minister Maliki has publicly condemned American-led actions such as the blockade of Husseniyah and raids into Sadr City, which did not receive the official sanction of the Iraqi government. Maliki feared thatsuch US-led offensives without Iraqi sanctioning worked to undermine the credibility of the government.....