Director of Research and Communications at Ifri and Editor-in-Chief of Politique étrangère. He holds a Ph.D. in Political Science from University Paris 1 Panthéon-Sorbonne and taught for many years a course on Terrorism at Sciences Po. He published several books including La Guerre de vingt ans (Robert Laffont, 2021 with Elie Tenenbaum), Intifada française ? (Ellipses, 2012) and War 2.0: Irregular Warfare in the Information Age (Praeger, 2009 with Thomas Rid; translated in Chinese in 2011). His articles appeared in major journals (Policy Review, Internationale Politik, Commentaire, Études, etc.).