Mark L. Haas, author, is Professor of Political Science at Duquesne University. He was formerly National Security Fellow at the Olin Institute for Strategic Studies and International Security Fellow at the Belfer Center for Science and International Affairs, both at Harvard. Haas received his Ph.D. in political science from the University of Virginia and his B.A. in political science, economics, and history from Duke. He is the author several books, including The Geriatric Peace: Population Aging and the Decline of War and Frenemies: When Ideological Enemies Ally; The Clash of Ideologies: Middle Eastern Politics and American Security; The Ideological Origins of Great Power Politics, 1789-1989