A member of the Free Democratic Party (FDP), Scheel entered the Diet of his native state of North Rhine–Westphalia in 1950 and served in the Bundestag during 1953–1974. He was also a member of the European Parliament during 1958–1969. In November 1961, Chancellor Konrad Adenauer appointed Scheel minister for economic cooperation, later retitled minister for development aid. Together with fellow FDP ministers, he resigned his post in October 1966 to protest tax increases proposed by Chancellor Ludwig Erhard.
Scheel was elected FDP chairman in January 1968 and became foreign minister and vice chancellor in the Willy Brandt government on 21 October 1969. A strong supporter of Ostpolitik, Scheel helped normalize relations with the Soviet Union and Poland and recognized the German Democratic Republic (GDR, East Germany) with the 1972 Basic Treaty on mutual relations, which marked the end of the Hallstein Doctrine. He was elected president on 15 May 1974. During his tenure, he proved to be an indefatigable promoter of closer European cooperation. Scheel retired from politics in June 1979.
O'Dochartaigh, Pól. Germany since 1945. Houndsmill, UK, and New York: Palgrave Macmillan, 2004.; Scheel, Walter. Walter Scheel im Gespräch mit Jürgen Emgert: Erinnerungen und Einsichten. Stuttgart: Hohenheim, 2004.; Webb, Adrian. Germany since 1945. London and New York: Longman, 1998.