He served as the United States Ambassador to Syria (1988–91) and Israel (1993–94), Special Assistant to President Ronald Reagan and Deputy Press Secretary of Foreign Affairs (1985–1986), and was Assistant Secretary of State for Near Eastern Affairs (1991–1993.) He was the founding director of Rice University's Baker Institute for Public Policy (1994-2022) He is a senior fellow at the Middle East Initiative at Harvard Kennedy School's Belfer Center for Science and International Affairs, a fellow of the American Academy of Arts and Sciences and is on the board of trustees of the Carnegie Corporation of New York. He is a Proprietor of the Boston Athenaeum. Djerejian was elected chairman of Occidental Petroleum Corporation's board of directors (2013–2015). Djerejian is the author of the book Danger and Opportunity: An American Ambassador's Journey Through the Middle East (Simon & Schuster, Threshold Editions, September 2008.