What causes some Muslim-Americans to become radicalized?

Video produced by Peggy Robinson.

When most people think of homegrown terrorists — Americans who become radicalized to committing extremist, violent acts — they might not picture a middle-class, married, educated American.

Yet, that’s the profile of most radicalized Americans, according to Peter Bergen, who studied the subject for his new book “United States of Jihad: Investigating America’s Homegrown Terrorists.” The book is also the basis for “Homegrown: The Counter-Terror Dilemma,” an HBO documentary released last month. Bergen joined the NewsHour’s chief foreign correspondent Margaret Warner to discuss the book.

When Syed Rizwan Farook and Tashfeen Malik opened fire at an office holiday party in San Bernadino, California, in December, the couple was married with a child and annual income of more than $70,000.

“They were basically living the American dream,” Bergen said. “So it’s a big puzzle, why would you then kill your fellow Americans? And I can’t say, even after two and a half years’ study, that I can answer that question.”

In the process of becoming radicalized, people tend to gather a community of people that share similar views, Bergen said.

“There is a sort of patent way people adopt these fundamentalist views. They increasingly seek out like-minded people, they kind of withdraw from society,” he said. “They basically are part of a self-reinforcing echo chamber of people who share their own views, and some may turn to violence.”

45 Americans have been killed by home-grown terrorists since the Sept. 11 attacks, making home-grown terrorism a “persistent, low-level threat” in the U.S., Bergen said. “To some degree, the threat has been managed. but it will persist at a low level for a long time,” he said.

Watch Bergen’s conversation with Warner above for more.

Support PBS NewsHour: