In the 1970s Rostow was a leader of the movement against détente with Russia and in 1981, President Ronald Reagan appointed him director of the Arms Control and Disarmament Agency.

From 1933 to 1934 Rostow studied economics at Cambridge University (where he would return in 1959 as the Pitt Professor of American History and Institutions) as a Henry Fellow.

After graduation, Rostow worked at the New York law firm of Cravath, deGersdorff, Swaine and Wood specializing in bankruptcy, corporations, and antitrust.

Leon Lipson says, "Throughout his career, he has woven ideas or beliefs about American constitutional bases and practices with others about international diplomacy, politics, and force.

He was an early and vocal critic of Japanese American internment and the Supreme Court decisions which supported it; in 1945 he wrote an influential paper in the Yale Law Journal which helped fuel the movement for restitution.

[3] At one point in 1962 – according to Alistair Cooke – he was considered by John F. Kennedy for appointment to the Supreme Court but geographical and religious issues interfered.

[8] In 1990, Rostow had this to say on the Geneva Convention/Oslo Accords and finding a peace between Israel and the Palestinians: "The Convention prohibits many of the inhumane practices of the Nazis and the Soviet Union during and before the Second World War – the mass transfer of people into and out of occupied territories for purposes of extermination, slave labor or colonization, for example....

They have not been 'deported' or 'transferred' to the area by the Government of Israel, and their movement involves none of the atrocious purposes or harmful effects on the existing population it is the goal of the Geneva Convention to prevent.