 Ambassador to NATO from 1965 to 1969, and earlier as U.S. Assistant Secretary of State for International Organization Affairs from 1961 to 1965.He was President of the University of Hawaii from 1969 to 1974, President of the World Academy of Art and Science in the 1990s, and Founding Dean of the University of Minnesota's Hubert H. Humphrey Institute of Public Affairs.Cleveland also served as Dean of the Maxwell School of Citizenship and Public Affairs from 1956 to 1961.