John Joseph Mearsheimer (/ˈmɪərʃaɪmər/; born December 14, 1947) is an American political scientist and international relations scholar, who belongs to the realist school of thought. He is the R. Wendell Harrison Distinguished Service Professor at the University of Chicago.
Mearsheimer proposed the theory of offensive realism which describes the interaction between great powers as dominated by a rational desire to achieve hegemony in a world of insecurity and uncertainty regarding other states' intentions. He was a vocal opponent of the Iraq War in 2003 and was almost alone in opposing Ukraine's decision to give up its nuclear weapons in 1994 and predicted that, without a deterrent, they would face Russian aggression. His most controversial views concern alleged influence by interest groups over US government actions in the Middle East which he wrote about in The Israel Lobby and U.S. Foreign Policy. In accordance with his theory, Mearsheimer considers that China's growing power will likely bring it into conflict with the United States. His work is frequently taught to and read by twenty-first century students of political science and international relations.