Zarqawi and Iraqi Resistance

Murad al-Shishani of the Jamestown Foundation has examined data on the Iraq War and determined that al-Qaeda in Mesopotamia accounts for 14% of all insurgent attacks, as well as a clear majority of those on foreign civilians and Iraqis and 42% of all suicide bombings. It's a little unclear how exactly responsibility for attacks is determined, but this does provide some valuable data on what, exactly, the level of violence is by the group which poses the biggest direct threat to broader efforts to counter terrorism as opposed to groups which seem likely to limit their interests to expelling coalition forces from Iraq.