January 05, 2023

Former US Deputy Secretary of State and Ambassador to Russia John J. Sullivan rejoins Mayer Brown

Mayer Brown announced today that former Deputy Secretary of State John J. Sullivan, who also served as the Acting Secretary of State and, most recently, as the US Ambassador to the Russian Federation, returned to the firm as a partner, resident in the Washington DC and New York offices. Ambassador Sullivan will advise clients on issues important to their business operations, including global risk, US sanctions and export controls, international trade disputes and regulation, and foreign investment.

Ambassador Sullivan is a leading authority on international legal and policy matters after an esteemed career in public service over four decades under five US presidents. In addition to his diplomatic posts, he has held senior positions at the Departments of Justice, Defense, and Commerce. As ambassador in Moscow until last fall, he adeptly managed the US Embassy for three years in the most challenging period of US-Russia relations in generations.

“We are delighted to welcome John back to Mayer Brown, where he has been a trusted counselor to clients and colleagues over the last 30 years,” said Mayer Brown Chair Jon Van Gorp. “Having served with distinction under multiple Republican and Democratic administrations, he brings a nuanced understanding of government and global policy and risk that will benefit our clients navigating these issues around the world.”

Prior to his ambassadorial appointment in December 2019, Ambassador Sullivan served as the Deputy Secretary of State for almost three years and was responsible for 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. In addition to his experience in foreign policy and, in particular, US-Russia relations and the war in Ukraine, he has worked extensively on trade issues important to multinational companies that do business around the world, including when he served as the Deputy Secretary of Commerce from 2007 to 2009.

From 2010 to 2016, Ambassador Sullivan served by appointment of the Obama Administration as Chair of the US-Iraq Business Dialogue, an advisory committee of business leaders on US commercial relations with Iraq. He also served previously as the Deputy General Counsel of the US Defense Department and in the Office of Legal Counsel at the US Department of Justice.

“Having closed a deeply meaningful chapter in public service at the Department of State and Embassy Moscow, I am so pleased to rejoin my talented colleagues at Mayer Brown and center my professional life in Washington and New York,” said Ambassador Sullivan. “The firm’s exceptional international reach provides an ideal fit for my practice, and I look forward to helping clients grow and protect their businesses in this challenging global environment.”

Ambassador Sullivan currently serves as a Distinguished Fellow at the School of Foreign Service of Georgetown University and a Distinguished Senior Fellow in the National Security Law Program at Columbia University School of Law. He is an elected member of the American Academy of Diplomacy. Early in his career, Ambassador Sullivan was a law clerk for Supreme Court Justice David H. Souter and first began working at Mayer Brown in the firm’s Supreme Court & Appellate practice in 1993.


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