Stephen Biddle

Stephen Biddle is a Senior Fellow at Delphi Global Research Center. He is a professor of international and public affairs at Columbia University where he directs the Concentration in International Security and Diplomacy, and Adjunct Senior Fellow for Defense Policy at the Council on Foreign Relations. His research focuses on military effectiveness, the conduct of war, and the role of technology in war. He has served on the Defense Department’s Defense Policy Board, on General David Petraeus’ Joint Strategic Assessment Team in Baghdad in 2007, as a Senior Advisor to the Central Command Assessment Team in Washington in 2008-9, as a member of General Stanley McChrystal’s Initial Strategic Assessment Team in Kabul in 2009, and on a variety of other government advisory panels and analytical teams.

He lectures regularly at the U.S. Army War College and other military schools, and has presented testimony before congressional committees on a variety of defense policy issues. His most recent book is Nonstate Warfare: The Military Methods of Guerillas, Warlords, and Militias(Princeton University Press, 2021). His book Military Power: Explaining Victory and Defeat in Modern Battle (Princeton University Press, 2004) won four prizes, including the Council on Foreign Relations Arthur Ross Award Silver Medal for 2005, and the 2005 Huntington Prize from Harvard University. He co-directs the Columbia Summer Workshop on Military Operations and Strategy (SWAMOS), and has won multiple teaching awards, most recently the Columbia School of International and Public Affairs Outstanding Teaching Award for 2025.