Stephen Walt

Stephen Martin Walt (born July 2, 1955) is an American political scientist specializing in international relations theory and U.S. foreign policy, renowned for advancing defensive realism through the balance-of-threat hypothesis, which posits that states form alliances primarily to counter perceived threats rather than mere power distributions. As the Robert and Renée Belfer Professor of International Affairs at Harvard University's John F. Kennedy School of Government since 1999, Walt has held prior faculty positions at Princeton University and the University of Chicago, shaping discourse on grand strategy and critiquing liberal interventionism as detrimental to American interests. His seminal works include The Origins of Alliances (1987), which empirically tested alliance formation using Cold War data, and Revolution and War (1996), analyzing how ideological upheavals influence great-power conflicts. Walt's collaboration with John Mearsheimer on The Israel Lobby and U.S. Foreign Policy (2007) argued that organized pro-Israel advocacy groups exert disproportionate influence on U.S. Middle East policy, often prioritizing Israeli security over broader American strategic objectives, a thesis that sparked intense debate and accusations of antisemitism from critics, though Walt maintained it stemmed from realist assessments of national interest rather than ethnic animus. In subsequent writings, such as The Hell of Good Intentions (2018), he has advocated for offshore balancing and restraint in U.S. commitments abroad, attributing post-Cold War foreign policy debacles to elite hubris and ideological overreach rather than material constraints alone.