William Sebastian Cohen (born August 28, 1940, in Bangor, Maine) is an American lawyer, author, politician, and entrepreneur who served as the U.S. Secretary of Defense from 1997 to 2001 under President Bill Clinton, becoming one of the few Republicans to hold a Cabinet position under a Democratic administration. He earned a Bachelor of Arts in government from Bowdoin College (1962) and a Bachelor of Laws from Boston University School of Law (1965), served in the U.S. Army Reserve, and practiced law in Maine before entering politics as a Republican. Cohen was elected to the U.S. House of Representatives (1973–1979) and later to the U.S. Senate (1979–1997), where he chaired committees on intelligence and armed services and gained a reputation for bipartisanship. As Secretary of Defense, he managed U.S. military responses to global challenges including operations in the Balkans and implementation of the Dayton Accords, advocated for military modernization, diversity in the armed forces, and addressed emerging threats like cyber warfare. After leaving office, he co-founded The Cohen Group in 2001 with his wife, Janet Langhart Cohen, a global consulting and lobbying firm focused on international business, policy advisory, and government relations. Cohen has been married twice: first to Barbara L. Cohen (with whom he has three children, ending in divorce) and since 1998 to Janet Langhart, a former model and journalist. He has authored several books, taught at institutions like the University of Maine, and maintained professional ties advising figures like Ileana Ros-Lehtinen. His legacy includes bridging partisan divides in national security and fostering U.S. global influence.