Prior to becoming deputy national security advisor, Steinberg served as director of the State Department's policy planning staff and as deputy assistant secretary for analysis in the Bureau of Intelligence and Research. Previously, he Steinberg was Senator Edward Kennedy's principal aide for the Senate Armed Services Committee and minority counsel, U.S. Senate Labor and Human Resources Committee.
Steinberg's most recent book is Difficult Transitions: Foreign Policy Troubles at the Outset of Presidential Power (2008) with Kurt Campbell. Steinberg received a B.A. from Harvard and a J.D. from Yale Law School. His wife, Sherburne Abbott, is vice president for sustainability initiatives and University Professor of Sustainability Science and Policy at Syracuse University.