PhD, Temple University, Pennsylvania, 1974. US-amerikanischer Islamwissenschaftler. Professor of International Affairs and Islamic Studies, Georgetown University, Washington, DC. Founding Director, Alwaleed Center for Muslim-Christian Understanding, Walsh School of Foreign Service. Loyola Professor of Middle East Studies, College of the Holy Cross.; 2019 Professor of Religion and International Affairs and Founding Director of the Prince Alwaleed Bin Talal Center for Muslim-Christian Understanding in the Walsh School of Foreign Service at Georgetown University; Islamwissenschaftler