Recent jihadist attacks and plots by American citizens or longtime residents of the United States have dramatized the danger from domestic terrorism in the name of Islam. The United States once was considered by many as virtually immune from the type of violence associated with alienated immigrant communities in European nations. But the immunity -- if it ever existed -- has worn off, judging by recent events, including the killing of 13 people at Fort Hood, Texas, allegedly by an Arab-American; guilty pleas by a Pakistani-American who tried to detonate a car bomb in Times Square and an Afghan immigrant who planned to bomb the New York subway system. Still in dispute, though, is whether the motivation lies in personal problems, social discrimination or an imported ideology that has grafted itself onto Islam, a religion practiced today by 1.6 billion people, including 2.5 million in the United States.

Peter Katel is a CQ Researcher contributing writer who previously reported on Haiti and Latin America for Time and Newsweek and covered the Southwest for newspapers in New Mexico. He has received several journalism awards, including the Bartolomé Mitre Award for drug coverage from the Inter-American Press Association and awards for investigative and interpretive reporting from the New Mexico Press Association. He holds an A.B. in university studies from the University of New Mexico.