In 1945 Waldheim joined the Austrian diplomatic service and served as First Secretary of the Legation in France (1948-1951) and head of the personnel department of the Ministry for Foreign Affairs (1951-55). This was followed by diplomatic posts in Canada (1956-60) and as head of the Political Department in the Austrian Ministry for Foreign Affairs (1960-62).
In 1964 Waldheim became Austria's permanent representative to the United Nations. He held this post for over four years and during this period served as chairman of the Committee of the Peaceful Uses of Outer Space.
Waldheim returned to Austria in 1968 to take up the post of Federal Minister for Foreign Affairs. This was followed by the post as Chairman of the Safeguards Committee of the International Atomic Energy Agency.
In 1972 Waldheim became Secretary-General of the United Nations. He held the post for nine years and during this period he made several visits in an attempt to bring an end to military and political conflict. This included South Africa, Cyprus, Syria, Lebanon, Israel, Egypt, Jordan, India, Pakistan, Bangladesh and Vietnam.
Waldheim was elected as president of Austria in 1986. Soon after his victory it was revealled that during the Second World War Waldheim was a Nazi intelligence officer who was involved in the transportation of Jews to concentration camps. This information was partly responsible for Waldheim being defeated in 1992.
The US Justice Department published a report in 1994 confirmed that Waldheim had been involved in atrocities against Jews, civilians and Allied soldiers during the war.