Ross was born in San Francisco and grew up in Marin County. His Jewish mother and Catholic stepfather raised him in a non-religious atmosphere. Ross graduated from University of California, Los Angeles in 1970 and did graduate work there, writing his doctoral dissertation on Soviet decision-making. He later became religiously Jewish after the Six Day War.
In 2002 he co-founded the Kol Shalom synagogue in Rockville, Maryland. During President Jimmy Carter's administration, Ross worked under Deputy Assistant Secretary of Defense Paul Wolfowitz in the Pentagon. There, he co-authored a study recommending greater U.S. intervention in "the Persian Gulf Region because of our need for Persian Gulf oil and because events in the Persian Gulf affect the Arab-Israeli conflict." During the Reagan administration, Ross served as director of Near East and South Asian affairs in the National Security Council and Deputy Director of the Pentagon's Office of Net Assessment (1982-84). Ross returned briefly to academia in the 1980s, serving as executive director of the Berkeley-Stanford program on Soviet International Behavior from 1984-1986. In the mid-1980s Ross co-founded with Martin Indyk the American Israel Public Affairs Committee (AIPAC)-sponsored Washington Institute for Near East Policy ("WINEP"). His first WINEP paper called for appointment of a "non-Arabist Special Middle East envoy" who would "not feel guilty about our relationship with Israel."
In the President George H. W. Bush administration he was director of the United States State Department's Policy Planning Staff, working on U.S. policy toward the former Soviet Union, the reunification of Germany and its integration into NATO, arms control, and the 1991 Gulf War. He also worked with Secretary of State James Baker on convincing Arab and Israeli leaders to attend the 1991 a Middle East peace conference in Madrid, Spain.