Diego Gambetta (PhD, FBA) is Carlo Alberto Chair in social and political science at the Collegio Carlo Alberto, Turin, Italy, and Emeritus Fellow of Nuffield College, Oxford. He has published academic books and articles, on trust and signalling theory, criminal organisations, the North-South Italian divide, and violent extremists. For the general public he has written on Primo Levi's death, discursive machismo, and heroic impatience. He was awarded the "Paolo Borsellino Prize" for his book on the Sicilian Mafia. He has held visiting positions at several universities (Chicago, Columbia, Science Po, College de France, ETH, Stanford, NYU). In 2000 he became a Fellow of the British Academy. Thomas Hegghammer is Senior Research Fellow in Politics at All Souls College, Oxford University. He is a political scientist and historian who specializes in the study of militant Islamist groups. His books include Jihad in Saudi Arabia: Violence and Pan-Islamism since 1979 (Cambridge 2010), JIihadi Culture: The Art and Social Practices of Militant Islamists (Cambridge 2017), and The Caravan: Abdallah Azzam and the Rise of Global Jihad (Cambridge 2020). He worked for two decades at the Norwegian Defence Research Establishment (FFI) in Oslo and has held fellowships at Princeton, Harvard, and Stanford Universitites as well as at the Institute for Advanced Study in Princeton.
