Marc Sageman is a forensic psychiatrist and a terrorism expert. Between 1984 and 1991, he worked for the CIA. At the end of the 1980s, he was stationed in Islamabad, where he ran the United States’ unilateral programs with the Afghan Mujahedin. Sageman, who also holds a PhD in sociology, returned to the world of medicine in 1991 to become a psychiatry resident at the University of Pennsylvania. After the terrorist attacks of 9/11, he collected biographical material on about 400 Al Qaeda terrorists, which resulted in the books Understanding Terror Networks (2004) and Leaderless Jihad: Terror Networks in the Twenty-First Century (2008). Sageman has taught at various American universities and is currently a Senior Fellow at Foreign Policy Research Institute.