Perspective Expert insights on a timely policy issue C O R P O R A T I O N T he purposes of this Perspective are to help identify threats to U.S. interests posed by the Islamic State of Iraq and the Levant (ISIL), 1 propose a context in which ISIL should be judged (particularly ISIL’s character and motivations, as well as key regional and global issues that frame the context), provide an initial framework for interpreting these insights, and outline a way ahead for developing and assessing courses of action and generating concrete options. his paper does not attempt to develop discrete courses of action or critique current ones; rather, it seeks to outline general principles that U.S. policymakers must consider when conceiving and weighing appropriate strategies to combat ISIL. Threats to U.S. Interests In the wake of the recent attacks in Brussels, Paris, and California, ISIL has demonstrated the will and capability to pose the threat of terror attack in the West, and it has shown an even greater threat to the Middle East, Africa, and South and Central Asia. What is not as clear is how threats to the countries and peoples of the Middle East afect U.S. core interests. hese threats have longer-term manifestations, and nations in the region and close to it are, at least in the normal calculus of state power, far more capable than ISIL. hreats that remain at continental distances from the U.S. home- land for now but pose larger dangers than just terror attacks in the future are less certain and harder to determine. hey are certainly possible, even if not currently manifest. Further, although military force could remove ISIL’s control of territory, it could not elimi- nate the underlying ideology or support. Still, the question of why ighting ISIL is the business of the United States rather than that of Middle Eastern or European countries is a valid one. Deining the Context for Understanding ISIL Starting with ISIL itself and its so-called caliphate, we examine critical elements of the problem from the center and work outward to the global context. Knowing the Enemy Understanding the Islamic State and Principles for Defeating It Terrence K. Kelly, James Dobbins, Barbara Sude, and Ben Connable