John Mueller is a senior fellow at the Cato Institute and a political scientist with the Mershon Center for International Security Studies at Ohio State University. He is the co‐​author (with Mark G. Stewart) of “Chasing Ghosts: The Policing of Terrorism,” published by Oxford University Press in 2016. He is also the author of “The Stupidity of War: American Foreign Policy and the Case for Complacency,” published earlier this year by Cambridge University Press.