After Zarquawi
For a more accurate picture of how the Al Qaeda connection works and doesn’t work, see After Zarquawi: The Dilemmas and Future of Al Qaeda in Iraq, by Brian Fishman, in the Washington Quarterly, Autumn 2006, p. 19
He explains the differences between Zarquawi and Bin Laden’s Al Qaeda, how they came together for tactical reasons, but how they split over Zarquawi’s willingness to kill other Moslems.