Steinberg was born to a Jewish family in Boston, Massachusetts.Jewish Virtual Library: "James B. Steinberg" retrieved October 26, 2013. He was educated at Phillips Academy (1970), Harvard College (1973), and Yale Law School (1978). His previous positions included a senior fellowship for US Strategic Policy at the International Institute for Strategic Studies in London, UK (1985–1987), and senior analyst at RAND Corporation (1989–1993). Steinberg also served as a Senior Advisor to the Markle Foundation (2000–2001) and was a member of the Markle Task Force on National Security in the Information Age.
