An early enemy of isolationism, he was Chairman of the Senate Foreign Relations Committee from 1959 to 1974. He was an active critic of US foreign policy in the 1960s and 1970s, attacking particularly the US involvement in the Vietnam War, and urging that Congress should have more control over the President’s powers to make war. A Rhodes Scholar himself, in 1946 he sponsored the Fulbright Act, which provided funds for the exchange of students and teachers between the USA and other countries.