As the battle between the United States and al-Qaeda and its associated forces continues, in a large number of geographic locations and seemingly without end, the targeting decisions undertaken by both sides and the way in which they have been justified to their respective constituencies deserve careful scrutiny. Matthew Hoisington addresses a subset of the decision-making process, namely, the instrumentalization of international humanitarian law (IHL) and the Islamic jus in bello for the purposes of targeting. The article begins with an examination of the radical innovations in the Islamic jus in bello that resulted in its instrumentalization by al-Qaeda and other Islamic armed groups in the name of jihad. It then addresses the key legal arguments of the U.S.-led response, particularly post-September 11. Finally, it offers a critical appraisal of the use of targeting rules to justify killing by both sides.