Andrew J. Bacevich, Sr. is an American historian specializing in international relations, security studies, American foreign policy, and American diplomatic and military history. He is a Professor Emeritus of International Relations and History at the Boston University Frederick S. Pardee School of Global Studies. He is also a retired career officer in the Armor Branch of the United States Army, retiring with the rank of Colonel. He is a former director of Boston University’s Center for International Relations.