From Wikipedia, the free encyclopedia. John J. Mearsheimer, PhD (born December 1947) is an American professor of Political Science at the University of Chicago. He is an international relations theorist. Known for his book on offensive realism, The Tragedy of Great Power Politics, more recently Mearsheimer has attracted attention for co-authoring and publishing the article The Israel Lobby and U.S. Foreign Policy, which was subsequently published as a book, becoming a New York Times Best Seller ...