After his release from British captivity in January 1946, Heisenberg and several of his closest colleagues settled in the northern university town of Göttingen, where he became the director of the Kaiser Wilhelm Institute for Physics. He devoted himself to two large tasks: the reconstruction of his institute as a leading physics research center, and the revival of research in the emerging West German republic. Working with western authorities and German political leaders, Heisenberg sought a direct role for the federal government in forming a national policy for science and technology and a direct role for science advisors to the new federal chancellor, Konrad Adenauer.
"I wished to procure for science some right to take the initiative in public affairs."
—Heisenberg, recollection
Such aims found expression in the German Research Council (Deutscher Forschungsrat), founded in 1949 and composed of 15 leading scientists, with Heisenberg as president. The new council represented German science in international affairs and directly in the chancellor's office.
The new Research Council contradicted the long tradition in Germany that science fell under the authority of the cultural ministers of each "Land" (state). The council was increasingly challenged by the cultural ministers, who supported their own organization, the Emergency Association of German Science (Notgemeinschaft der Deutschen Wissenschaft), which rivaled Heisenberg's Council. The cultural ministers eventually prevailed, much to Heisenberg's regret. The two bodies merged in 1951 into the present-day German Research Society (Deutsche Forschungsgemeinschaft), one of the main supporters of academic research in Germany. Heisenberg was elected to the presidential committee of the new association and directed its Commission for Atomic Physics, which coordinated all nuclear research, except fission research.
The occupation authorities forbade any fission research in Germany. Heisenberg tirelessly argued for a lifting of the ban and for German preparations to begin reactor construction as soon as the ban was lifted. He saw nuclear energy as a future source of electric power for the revived German economy and as an export industry of great importance. The Western Allies, led by the United States, finally lifted all restrictions in 1955 when they granted sovereignty to West Germany. Heisenberg successfully urged the creation of a cabinet-level nuclear energy ministry, and served as a leading member of various federal and state atomic commissions. Within a decade, West Germany was a leading exporter of nuclear technology.
While Heisenberg supported the economic development of nuclear energy, he and other scientists opposed Chancellor Adenauer's acceptance of NATO plans to equip the West German army with tactical nuclear weapons. They published the "Göttingen Manifesto." Although the West German government strove to obtain nuclear warheads, the German army remained non-nuclear in the sense that it possessed the delivery vehicles but the U.S. retained control of the warheads.
Heisenberg also worked tirelessly to reestablish international relations. He undertook a lecture tour to England and Scotland in 1947, and to Copenhagen and the United States in 1950, and throughout the world thereafter. When in 1952 the European Council for Nuclear Research came into being, Heisenberg headed the German delegation that participated in the decision to locate the European accelerator for high energy physics, CERN, near Geneva, Switzerland. He headed CERN's Scientific Policy Committee for many years. In a further effort to reestablish international relations, Heisenberg gladly accepted Adenauer's appointment as president of the Alexander von Humboldt Foundation. The purpose of the foundation is to enable young scholars and scientists from around the world to collaborate with German colleagues while long-term guests at German research institutes.
Heisenberg also worked to expand his institute, renamed the Max Planck Institute for Physics in 1948. Its research focus included the study of astrophysics, and especially of experimental and theoretical high-energy physics. His own work continued to focus on the search for a consistent, unified quantum theory of elementary particles. These efforts harmonized with the somewhat idealistic philosophical views that he presented at that time to a variety of public audiences. He gave perhaps the most widely known of his lecture series at St. Andrews University in Scotland during the winter of 1955-56 and published it as a monograph in English as Physics and Philosophy, and in German as Physik und Philosophie.
The search for a unified theory of elementary particles led Heisenberg to a renewed intensive collaboration with his long-time colleague Wolfgang Pauli. This yielded in early 1958 the prospect of a new quantum theory as revolutionary as the quantum mechanics they had developed decades earlier (the so-called "Weltformel," world formula). But in the end the new theory proved unsuccessful. Pauli withdrew from endorsing this theory and died later that year. The research continues to this day among Heisenberg's successors and other researchers.
In 1958 Heisenberg moved the Max Planck Institute for Physics to Munich, where it became the Max Planck Institute for Physics and Astrophysics. Heisenberg also became more involved in the activities and research at CERN. (He never did receive a full-time appointment as a full professor, an "Ordinarius," after the war, although he held honorary professorships in Göttingen and Munich.) He continued his search for a unified theory of elementary particles during the 1960s, while continuing to travel widely. He retired from the institute in 1970. He visited the United States for the last time in 1972.
Heisenberg died of cancer at his home in Munich on February 1, 1976.