I am a Professor of Political Science at Columbia University and Director of the Saltzman Institute of War and Peace Studies. Prior to joining Columbia, I was a Professor in the School of Foreign Service at Georgetown University.  I am a contributor at the Good Authority blog, and a non-resident senior fellow at the Brookings Institution.

My research and teaching interests focus on the domestic politics of international relations and US foreign policy, especially the role of leaders, the presidency, and the politics of using force.  My new book, The Insiders’ Game: How Elites Make War and Peace, was published in 2024 by Princeton University Press (Princeton Studies in International History and Politics) and won the 2025 Best Book Award from ISA’s Foreign Policy Analysis Section.  The book argues that elite politics are central to understanding when and how democracies fight wars.  An article adapted from the book, “Politics Can’t Stop at the Water’s Edge,” appeared in the March/April 2024 of Foreign Affairs. My first book, Leaders at War: How Presidents Shape Military Interventions, was published by Cornell University Press in 2011, and received the 2012 Jervis-Schroeder Best Book Award from APSA’s International History and Politics section.

My research also examines other aspects of the politics of foreign policy and international conflict, including how leaders interact with advisers, the politics of leaks, how women’s suffrage shapes the democratic peace, the domestic politics of nuclear choices, and the role of high-level diplomacy in US foreign policy.  My work has been published in the Annual Review of Political Science, International Organization, International Security, World Politics, International Studies Quarterly, Security Studies, the Journal of Conflict Resolution,  the American Journal of Political Science, International Studies Review, and Foreign Affairs. 

Updated October 2025