Source: Multi-national Corps-Iraq, Multi-national Force-Iraq, February 2006

Excerpt from the GAO study: "As shown in Figure 1, enemy-initiated attacks against the coalition, its Iraqi partners, and infrastructure increased in number over time. The highest peak occurred during October 2005, around the time of Ramadan and the October referendum on Iraq's constitution. This followed earlier peaks in August and November 2004 and January 2005. According to a senior U.S. military officer, attack levels ebb and flow as the various insurgent groups -- almost all of which are an intrinsic part of Iraq's population -- rearm and attack again.

"As the administration has reported, insurgents share the goal of expelling the coalition from Iraq and destabilizing the Iraqi government to pursue their individual and, at times, conflicting goals. Iraqi Sunnis make up the largest portion of the insurgency and present the most significant threat to stability in Iraq. In February 2006, the Director of National Intelligence reported that the Iraqi Sunnis' disaffection is likely to remain high in 2006, even if a broad, inclusive national government emerges. These insurgents continue to demonstrate the ability to recruit, supply and attack coalition and Iraqi security forces. Their leaders continue to exploit Islamic themes, nationalism, and personal grievances to fuel opposition to the government and recruit more fighters..."