Ambassador John J. Sullivan, former US deputy secretary of state and former US ambassador to the Russian Federation, is a partner in Mayer Brown's Washington DC and New York offices and co-lead of the firm's National Security practice. He is also a Distinguished Scholar at the School of Foreign Service of Georgetown University and a Distinguished Fellow at the School of International and Public Affairs of Columbia University. He serves as a Contributor to CBS News, is quoted frequently in international media as a leading authority on foreign affairs, and has written an award-winning and critically acclaimed book on his experiences as ambassador, Midnight in Moscow, which was published by Little, Brown and Company in August 2024. 

Ambassador Sullivan is Chairman of the Board of the US Institute of Peace, after his nomination to the board by President Biden and unanimous confirmation by the Senate. He also has been appointed by Congress to serve as a member of the bipartisan congressional Commission on Reform and Modernization of the Department of State. 

At Mayer Brown, Ambassador Sullivan advises clients on global risk and foreign policy, as well as US sanctions and export controls, international trade disputes and regulation, foreign investment, and other sensitive issues at the intersection of international commerce and national security policy. He is often consulted as an expert and has testified before Congress, including the Senate Foreign Relations Committee, in that capacity. In addition to his expertise in foreign policy and, in particular, US-Russia relations, he has worked extensively on trade issues important to multinational companies doing business around the world after serving as the US deputy secretary of commerce. 

Ambassador Sullivan's career spans four decades in public service in prominent diplomatic and legal positions under five US presidents and in private law practice at Mayer Brown. Before rejoining the Firm in January 2023, he was the US ambassador to Russia from December 2019 to October 2022. During his tenure, he led the US Embassy through the most challenging period in US-Russia relations in generations. 

Prior to his post in Moscow, Ambassador Sullivan served for almost three years as the deputy secretary of state after a bipartisan 94-6 confirmation vote in the US Senate in 2017. In this senior role, he was responsible for both the formulation and conduct of US 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 private practice at Mayer Brown, which he first joined in 1993, Ambassador Sullivan has been a member of the Supreme Court and Appellate practice and was a co-founder of the National Security practice. From 2010 to 2016, he served by appointment of the Obama Administration as chair of the US-Iraq Business Dialogue, a government advisory committee of business leaders on US 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 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. 

Ambassador Sullivan received his bachelor's degree from Brown University and his law degree from the Columbia University School of Law, where he was 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 and the Council on Foreign Relations, and serves as a Distinguished Senior Fellow in the National Security Law Program at Columbia Law School. He is 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.