Tom previously served as Assistant to the President and Principal Deputy National Security Advisor. In that role, he was responsible for managing the US government's national security policy development and crisis management process. Tom chaired the Obama-Biden transition at the US Department of State. During the 2008 campaign, Tom headed President Obama's general election debate preparation effort.

Tom is a distinguished fellow at the Council on Foreign Relations, a non-resident senior fellow at Harvard Kennedy School's Belfer Center for Science and International Affairs, a distinguished fellow at the Asia Society, and a member of the Center on Global Energy Policy Advisory Board at Columbia University. From 2013-2017, he served on the Central Intelligence Agency’s External Advisory Board. Tom also chaired the Commission for Enhancing National Cybersecurity, which issued the December, 2016 Report [to the President] on Securing and Growing the Digital Economy.

Tom has worked closely with and advised three US presidents since his first position at the White House in 1977, working with President Carter. He served as assistant secretary of state and chief of staff at the U.S. Department of State during the Clinton administration. In this capacity, Tom was responsible for the development and implementation of the department's major policy initiatives. Tom has received the Secretary of State's Distinguished Service Award, the National Intelligence Distinguished Public Service Medal, the Department of Defense Medal for Distinguished Public Service, the Chairman of the Joint Chiefs of Staff Joint Distinguished Civilian Service Award, and the CIA's Director's Award.

Tom is also a member of the Council on Foreign Relations, the Aspen Strategy Group, and an honorary member of the Brookings Institution Board of Trustees. He received his undergraduate degree from Catholic University and his law degree from the University of Virginia.

Tom also previously served as Executive Vice President for Law and Policy at Fannie Mae where he was responsible for Fannie Mae’s legal, regulatory, government affairs, and public policy issues.

His return to the firm in 2014 began the fourth installment of his practice at O’Melveny. He started his legal career as an associate at the firm in 1985 and, before joining the Obama Administration in 2009, practiced as a partner representing clients on a range of sensitive governance, legal, regulatory, and policy matters. He also served as the national partner charged with overseeing the firm’s public interest and pro bono initiatives and led the firm’s successful effort to revitalize its pro bono commitment.

Tom lives in Washington, DC, with his wife, Ambassador Cathy Russell.

Ms. Russell served as Ambassador-at-Large for Global Women’s Issues at the US Department of State from 2013-2017.