During the Allied occupation, Gruber served as the first postwar governor of North Tyrol and was a founder of the Austrian People's Party. He served as foreign minister (1945–1953) under Karl Renner, Leopold Figl, and Julius Raab. Dismissed by some scholars as an amateur who concocted fanciful schemes and gave vitriolic, undiplomatic speeches, Gruber is credited by others with making positive contributions to the Second Republic's foreign policy.
The South Tyrol dispute, the restoration of Austrian sovereignty, and Westernization dominated Gruber's agenda. He sought revision of the St. Germain Treaty, which had awarded the South Tyrol to Italy in 1919. The Allies rejected alterations of the Italian border in Austria's favor, however. In the Gruber–De Gasperi Agreement (5 September 1946), Italy conceded limited autonomy for the South Tyroleans. Although the Italians violated its letter and spirit, the agreement acknowledged Austria's interest in the German minority, a starting point for future negotiations.
The goal of restoring full sovereignty through a state treaty proved just as elusive. The treaty's nomenclature derived from Austria's anomalous status as an occupied nonbelligerent under the theory, propounded in the Moscow Declaration, that Austria was Adolf Hitler's first territorial conquest. Under the Potsdam Declaration, the Soviets demanded the expropriation of Austria's German assets and applied a broader definition than the Allies were willing to concede. By 1950, German assets and Cold War conflicts stalled negotiations. Gruber helped break the stalemate by securing Brazilian sponsorship of a United Nations resolution encouraging the wartime Allies to expedite an Austrian treaty. Its passage in December 1952, with strong non-Western support, persuaded the Soviets that the treaty was more than just U.S. propaganda. In early 1953, Julius Raab sponsored Austro-Soviet talks on neutralization. A scandal over publication of Gruber's memoirs led to his resignation in autumn 1953. During the first of three stints as ambassador to the United States, he helped to win U.S. support for the 1955 Austrian State Treaty.
Gruber played an important role in Austria's economic Westernization. Despite his American sympathies, he nonetheless rejected American political strings as the price for Marshall Plan assistance but served as vice president of the Organization of European Economic Cooperation (OEEC) during 1949–1954. To allay Soviet fears, he rejected Austrian participation in the European Coal and Steel Community (ECSC) in 1951.
In 1987, during the Waldheim Affair, Gruber briefly served as special ambassador to the United States. Kurt Waldheim had been Gruber's secretary in the 1940s, and he staunchly defended Waldheim's reputation. Gruber died in Innsbruck on 1 February 1995.
Joseph Robert White
Bischof, Günter. "The Making of a Cold Warrior: Karl Gruber and Austrian Foreign Policy, 1945–1953." Austrian History Yearbook 26 (1995): 99–127.; Gruber, Karl. Between Liberation and Liberty: Austria in the Post-War World. Translated by Lionel Kochan. New York: Frederick Praeger, 1955.; Herzstein, Robert Edwin. Waldheim: The Missing Years. New York: Arbor House/William Morrow, 1988.