I am an Associate Professor in the Department of Politics and the Batten School of Leadership and Public Policy at the University of Virginia. My research focuses on national security, foreign policy, and international relations. I am a principal investigator for a Department of Defense Minerva Initiative project to map and analyze collaborative relationships between terrorist organizations. I've published articles in International Organization, Journal of Politics, International Studies Quarterly, The Journal of Conflict Resolution, and the Annual Review of Political Science, among other journals. My book, War and Democratic Constraint(with Matthew Baum), is now available from Princeton University Press. I serve on the editorial boards of the Journal of Politicsand theJournal of Global Security Studies.