Former US ambassador to Russia rejoins Mayer Brown

Former US ambassador to Russia rejoins Mayer Brown

This will be the third stint of the former diplomat John J. Sullivan with Mayer Brown

Former US Deputy Secretary of State John J. Sullivan has returned to Mayer Brown LLP as a partner. He will advise clients on a range of international issues. He served most recently as the ambassador to Russia.

Sullivan was the ambassador in Moscow for nearly three years before retiring from public service in September 2022. He served in that role under both the Trump and Biden administrations. He led the US Embassy during a turbulent period that included the upheaval of the pandemic and the Russian invasion of Ukraine.

At Mayer Brown, he will be based in both New York and Washington, D.C. He will be providing advice to businesses on a variety of topics such as global risk, US sanctions and export controls, international trade, and foreign investment, the firm said Thursday.

Sullivan worked under five presidents during his career in government. Before being appointed ambassador to Russia in late 2019, he served as deputy secretary of state and acting secretary of state under President Donald Trump. He was deputy secretary of commerce during the George W. Bush administration and has also held senior positions in the US Department of Justice and Department of Defense.

Sullivan had two stints with Mayer Brown in the past, from 1993 to 2003 and from 2011 to 2016.

In an interview with Law360 Pulse this week, Sullivan said his professional life in the private sector "has always been rooted in Mayer Brown," so it was the only firm he wanted to join after leaving government service.

"I've had so many friends over the years, close friends, who are still partners at the firm," he said. "If I was going to continue to have a professional life, it would be at Mayer Brown."

In 2015, Sullivan and Raj De co-founded the firm's national security practice. De told Law360 Pulse that businesses face a host of issues that include export controls, sanction risks, supply chain problems, cybersecurity matters, and cross-border investigations, he said.

"And I think the security issues that are impacting global business are only increasing in a dynamic geopolitical environment that John has been very much part of for the past several years," said De, who also leads the firm's global cybersecurity and data privacy practice.

Sullivan grappled with numerous challenges during his posting in Moscow, from the pandemic hampering diplomatic meetings to the detention of Americans and drastic staff cuts at the US Embassy.

Sullivan, who also teaches at the School of Foreign Service at Georgetown University, said he would draw upon his experience in government to help clients solve problems.

In his government roles over the past six years, he said, "I've been an advocate for US businesses investing and doing business abroad." At Mayer Brown, "my perspective will be broader, but I'll be helping (clients) doing business around the world with all the different legal, political, and other challenges that they may be faced with."

Mayer Brown Chair Jon Van Gorp said Sullivan has "served with distinction" under both Democratic and Republican administrations, bringing "a nuanced understanding of government and global policy and risk that will benefit our clients navigating these issues around the world.

"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," Van Gorp said in a statement.