As we approach the tenth anniversary of the 9/11 attacks next September, the United States, its Western allies, and nearly all states in the Islamic world are facing a weakened jihadi enemy, but one still capable of inflicting, or threatening to inflict, spectacular acts of terrorist violence. The recent attempts to send package bombs on cargo planes is only the latest in a series of plots suggesting that although al'Qa'ida and its cohorts have suffered a number of setbacks, the group and its affiliates and associates continue to pose a serious challenge to the security of the United States and its allies. Self-Inflicted Wounds: Debates and Divisions within al'Qa'ida and its Periphery examines the internal, or endogenous, reasons that have hastened the decline of the jihadi movement. In doing so, it exposes the jihadi movement, with al'Qa'ida at its helm, as one that lacks coherence and unity, despite its claims to the contrary. The report divides the jihadis' endogenous problems into two categories: internal divisions plaguing al'Qa'ida and the jihadi movement proper; and fault lines dividing the jihadi movement from other Muslim and Islamist actors. The internal jihadi divisions examined in this report include tactical disagreements over takfir (excommunication of Muslims) and the killing of Muslims; strategic disagreements over whether the jihadi struggle should focus on the near enemy (i.e., nominally Muslim regimes) or the far enemy (the United States and its Western allies).