Jonathan Stevenson is senior fellow for U.S. defense and managing editor of Survival at the International Institute for Strategic Studies (IISS). He was previously professor of strategic studies at the U.S. Naval War College, and he has served as director for political-military affairs, Middle East and North Africa, on the National Security Council. He is the author of several books, including Thinking Beyond the Unthinkable: Harnessing Doom from the Cold War to the Age of Terror and “We Wrecked the Place”: Contemplating and End to the Northern Irish Troubles.