Ambassador Sullivan is a Distinguished Fellow at the School of Foreign Service of Georgetown University. His career spans four decades in the public sector and in private law practice. Ambassador Sullivan served five presidents in prominent diplomatic and legal positions, including as U.S. Ambassador to the Russian Federation under Presidents Joe Biden (January 2021 to October 2022) and Donald Trump (December 2019 to January 2021). Before his post in Moscow, he served for almost three years as the U.S. Deputy Secretary of State after a bipartisan 94-6 confirmation vote in the U.S. Senate in 2017.  As deputy secretary, Ambassador Sullivan was responsible for both the formulation and conduct of U.S. foreign policy and the management of the State Department’s global operations. He was the acting Secretary of State in March-April 2018, among the longest tenures in history of anyone in that position.

In the private sector, Ambassador Sullivan was a partner in the global law firm Mayer Brown LLP, where he co-chaired the national security practice and focused on the complex intersections of global trade and investment and U.S. national security and foreign policies. From 2010 to 2016, he served by appointment of the Obama Administration as Chair of the U.S.-Iraq Business Dialogue, a government advisory committee of business leaders on U.S. commercial relations with Iraq.

Previously, Ambassador Sullivan held senior positions in the Departments of Justice, Defense, and Commerce in two prior administrations. Until January 2009, he was the U.S. Deputy Secretary of Commerce under President George W. Bush, following his service from 2005 to 2007 as the General Counsel of the Department. In President Bush’s first term, he was appointed Deputy General Counsel of the Defense Department by Secretary Donald H. Rumsfeld. In the George H.W. Bush Administration, Ambassador Sullivan was Counselor to Assistant Attorney General J. Michael Luttig in the Justice Department’s Office of Legal Counsel.

A native of Boston, Massachusetts, Ambassador Sullivan received his bachelor’s degree from Brown University and his law degree from the Columbia University School of Law, where he was a Harlan Fiske Stone Scholar and Book Reviews Editor of the Columbia Law Review. He was a law clerk for Associate Justice David H. Souter of the Supreme Court of the United States, and for Judge John Minor Wisdom of the United States Court of Appeals for the Fifth Circuit.

Ambassador Sullivan is a member of the American Academy of Diplomacy. He is also the recipient of numerous honors and awards, including the Secretary of State's Distinguished Service Award; the Department of State's Distinguished Honor Award; the Director of the Central Intelligence Agency's Ambassador of the Year Award; the Defense Intelligence Director's Award; the Chairman of the Joint Chiefs of Staff's Joint Meritorious Civilian Service Award; the Secretary of Defense's Medal for Exceptional Public Service; and the Columbia University School of Law, DC Alumni Association, Distinguished Alumnus Award.