Gideon Rose is managing editor of Foreign Affairs magazine and an expert on terrorism, among other issues, in the Middle East and South Asia. He is based in New York City.

Michael Radu is co-chairman of the Center on Terrorism, Counter-Terrorism and Homeland Security at the Foreign Policy Research Institute in Philadelphia. He has studied terrorist groups around the world and is an expert on terrorism and extremism in Turkey.

Sandra Mackey is a freelance journalist who has written widely on Islamic extremism, especially in Iraq and Lebanon. She is the author several books on Islam and politics in the Middle East including Mirror of the Arab World: Lebanon in Conflict (2008). She lives in Atlanta, Ga.

Bruce Hoffman is a professor in the security studies program at Georgetown University in Washington, D.C. He teaches graduate courses in terrorism and counterterrorism and insurgency and counterinsurgency, as well as other international security subjects.

Tawfik Hamid describes himself as a former member of an Islamic extremist movement Jamma’a Islameia who now speaks out for political and religious reform in the Muslim world.

James Piscatori is a professor and deputy director of the Centre for Arab and Islamic Studies at the Australian National University in Canberra, Australia. He is formerly a senior scholar at the Oxford Centre for Islamic Studies in Oxford, England. He is a leading scholar in Islamic communities in the West.

Sohail Hashmi is an associate professor of international relations at Mount Holyoke College in South Hadley, Mass. He is an expert on Islam, pluralism, Islamic political thought and jihad. He posits that Islam lacks a tradition of political thought.

Charles W. Sasser is a former Green Beret and combat correspondent and author of the 2008 book God in the Foxhole, a collection of stories of members of the military who used their faith to persevere in combat. He lives in Chouteau, Okla.

James M. Dunn is vice president and chief investment officer at Wake Forest University in Winston-Salem, N.C. He was executive director of the Baptist Joint Committee on Public Affairs for 19 years and is frequently quoted on church-state issues.