In June 1950, Chancellor Konrad Adenauer chose Hallstein to lead the West German delegation to discuss the Schumann Plan for European integration in Paris. Along with Jean Monnet, Hallstein was one of the key founders of the European Coal and Steel Community (ECSC). When this task was completed in August, Hallstein joined the Chancellor's Office as a state secretary for foreign affairs. Hallstein moved to the foreign office in 1951, and in 1955 he rose to prominence as the creator of the so-called Hallstein Doctrine, which would serve as a foundation for West German foreign policy for the next fifteen years. The Hallstein Doctrine stated that with the exception of the Soviet Union, West Germany would not establish diplomatic relations with any state that recognized the German Democratic Republic (GDR, East Germany).
Although perhaps not as well known for this as for his doctrine, Hallstein went on to win recognition for his work in the European Economic Community (EEC). He became president of the EEC Commission (EC) in 1958 and unveiled the Hallstein Plan for the EC the following year. His vision of a united Europe clashed with the emerging Gaullist notion of a "Europe of Nations." Hallstein resigned his post in 1967. He returned briefly to German politics as a representative in the Bundestag from 1969 to 1972. Hallstein died in Stuttgart on 29 March 1982.
Hallstein, Walter. Europe in the Making. New York: Norton, 1973.; Kilian, Werner. Hallstein Doktrin: Der Diplomatischen Krieg Zwischen der BRD und der DDR, 1955–1973. Berlin: Duncker and Humblot, 2001.; Loth, Wilfried, William Wallace, and Wolfgang Wessels, eds. Walter Hallstein: The Forgotten European? New York: St. Martin's, 1998.