Élie Tenenbaum is a researcher at the IFRI’s Centre des Etudes de sécurité (Security Studies Center), where he coordinates the defense research lab. As a specialist with a doctorate in history and a degree from France’s Sciences Po School, he has been a visiting fellow at Columbia University and has taught international security at Sciences Po and International Relations History at the University of Lorraine. His work focuses in particular on the issue of irregular warfare and hybrid threats, as well as on France’s defense policy and military operations. He has written numerous articles and books about history and strategy, including Partisans et centurions. Une histoire de la guerre irrégulière au xxe siècle (Partisans and Centurions: A History of Irregular Warfare in the 20th Century), Perrin, 2018, and La guerre de Vingt Ans. Djihadisme et contre-terrorisme au xxie siècle (The Twenty-Year War: Jihadism and Counter-Terrorism in the 21st Century), Paris, Robert Laffont, 2020.