Dean Rusk taught political science in the 1930's and served in World War II, after which he joined the State Department under the mentorship of George C. Marshall. In 1950, Rusk was named Assistant Secretary of State for Far Eastern affairs. Under Secretary Dean Acheson, Rusk was involved in policy-making during the Korean War. Leaving the State Department in 1952 to become the head of the Rockefeller Foundation, Rusk returned to public service when President Kennedy appointed him Secretary of State in 1961. He continued as Secretary of State under President Johnson, and supported international economic cooperation and military opposition to Communism. Along with Robert McNamara, Rusk became a major apologist for the Johnson Administration's escalation of American involvement in the Vietnam War. In 1970, Rusk became a professor of international law at the University of Georgia.