In August 2011 the Obama administration released a new “counter-radicalization” policy titled “Empowering Local Partners to Prevent Violent Extremism in the United States.”

The Southern Poverty Law Center, which tracks hate groups and domestic terrorism, in February 2011 released an annual report showing “explosive growth” in the number of active hate groups in the United States and in the number of antigovernment “Patriot” movements. These groups often have a religious element to their agendas.

Read an article about the massacre in Norway in July 2011 by anti-Islamic extremist Anders Behring Breivik, who claimed to be a Christian crusader even as he rejected central Christian beliefs, which highlighted the phenomenon of right-wing violence.

Richard Barrett is the United Nations Coordinator of the Analytical Support and Sanctions Implementation Monitoring Team, also known as the al-Qaeda and Taliban Monitoring Team. Barrett advises the Security Council on the threat posed by al-Qaeda.

A Washington Post-ABC News poll conducted in March 2006 found that 58 percent of Americans said Islam is “prone to violent extremism” and that 27 percent admitted to feeling prejudice against Muslims and Arabs.

Richard A. Landes is an associate professor of history at Boston University, specializing in messianic and millennial movements. He was the director of the now inactive Center for Millennial Studies at Boston University.

Michael Barkun is a professor emeritus of political science at the Maxwell School at Syracuse University in Syracuse, New York. He is the author of A Culture of Conspiracy: Apocalyptic Visions in Contemporary America and Religion and the Racist Right: The Origins of the Christian Identity Movement.

Read an April 24, 2013, column on CNN’s website about the Boston marathon bombing and how terrorist acts are quickly and inaccurately categorized as “Muslim extremism.”