Although terrorism is an age-old phenomenon, jihad ideology is distinctive in its ambition to abandon the principle of state sovereignty, overthrow the modern state system, and replace it with an extremely radical interpretation of an Islamic world order. These characteristics reflect a radical break from traditional objectives promoted by terrorist groups. In "Combating Jihadism" Barak Mendelsohn argues that the distinctiveness of the al Qaeda threat led the international community to change its approach to counterterrorism. Contrary to common yet erroneous conceptions, the United States, in its role as a hegemon, was critical for the formulation of a multilateral response. While most analyses of hegemony have focused on power, Mendelsohn firmly grounds the phenomenon in a web of shared norms and rules relating to the hegemon's freedom of action. Consequently, he explains why US leadership in counterterrorism efforts was in some spheres successful, when in others it failed or did not even seek to establish multilateral collaborative frameworks. Tracing the ways in which international cooperation has stopped terrorist efforts, "Combating Jihadism" provides a nuanced, innovative, and timely reinterpretation of the war on terrorism and the role of the United States in leading the fight against al Qaeda and its affiliates.