Terrorism expert reveals 4 key reasons people become violent extremists
Peter Bergen, who was the first journalist to interview Osama bin Laden on television and has written five books on terrorism, explored what attracts Americans to radical Islam in his new book, "The United States of Jihad."
We asked Bergen to share a list of key reasons that people transform into violent extremists willing to commit deadly acts of terrorism.
Produced by Pamela Engel and Graham Flanagan
Follow BI Video: On Twitter