Director of Centre for the Study of Terrorism and Political Violence at the University of St. Andrews, Scotland. Leading expert on Hizballah, Hamas, al-Qaeda and other militant Islamic movements. International Editorial Advisory Board member of the academic journal Studies in Conflict and Terrorism. CNN’s Principal Consultant on Terrorism before and after 11 September 2001. Invited to testify before the 9–11 Commission in a panel on the Attackers, Intelligence, and Counter-Terrorism Policy (2003). Currently directing a CNN project on Al-Qaeda’s network around the world.

Publications include: Hizballah in Lebanon (1997) and other numerous articles and monographs on terrorism and counter-terrorism.