I've seen this sort of thing blogged in other places, but there's a nice Sydney Freedberg piece in the National Journal that describes how Al Qaeda is not on good terms with Iraqis:
Ironically, no secularist force has more contempt for traditionaltribal ways than does Al Qaeda, whose Salafist ideology sees tribes asa vestige of the jahiliya, the pagan "time of ignorance" before Islam."Al Qaeda has just as hard a time understanding those tribalrelationships as we did," said Brian Fishman,a senior associate at West Point's Combating Terrorism Center. And, headded, Al Qaeda is caught right now because it is having to appeal tothree diverse constituencies: angry Muslims worldwide, who cheer on anyDavid who is defying the U.S. Goliath; Sunni Arabs in Iraq, who have nodesire to replace U.S. occupiers with Qaeda overlords; and the globalcommunity of Salafis, who put ideological purity before battlefieldsuccess. The videotaped beheadings that pleased Al Qaeda's hard-coresupporters appalled most ordinary Muslims. And to impress theinternational Salafis, including the exiled Saudi millionaires whoprovide much of Al Qaeda's funding, the group had to try to impose itswill, both military and spiritual, on its fractious Iraqi allies.