Leopold von Ranke's Primat der Aussenpolitik concept. Herwig wrote that for Hillgruber history was made by small political and military elites who were not prisoners of forces beyond their control, and that instead made history through their choices and decisions. A striking example of Hillgruber's conservative politics came in 1979 when he and his protégé Hildebrand wrote a series of articles to mark the 40th anniversary of the German-Soviet non-aggression pact of 1939. The German historians' Gerd Ueberschär and Rolf-Dieter Müller commented that Hillgruber and Hildebrand "..developed a highly politicized and staunchly conservative interpretation of it [the non-aggression pact of 1939]". Ueberschär and Müller remarked that the articles that Hillgruber and Hildebrand wrote were not really about the Molotov-Ribbentrop pact, but instead were the means of Hillgruber and Hildebrand could attack various trends in the world of 1979 such as détente with the Soviet Union, radical students on university campuses, the theory that the Soviet Union was not a totalitarian dictatorship, and the rise of the functionalist school of historiography that they disapproved of. Ueberschär and Müller noted one of the Hillgruber-Hildebrand articles had as its subtitle "Parallels with Today?" and that article proceeded to answer that question in the affirmative, with Hillgruber and Hildebrand claiming that there was no real difference between the policies of the Soviet Union in 1939 and 1979. Ueberschär and Müller wrote that the article was really about the world of 1979 as opposed to the world of 1939. The Hillgruber-Hildebrad articles were just as conservative intellectually as they were politically. Hillgruber and Hildebrand argued that reach a proper historical "understanding" of the 1939 pact that one had to study and understand in depth the personalities of Hitler and Stalin as instead of social forces in Germany and the Soviet Union. Hillgruber attacked the "many new 'revisionist' views amongst West German historians about an alleged 'polycracy' in the Third Reich", arguing for the traditional picture of Hitler as "the master of the Third Reich". Hillgruber and Hildebrand made a case for the traditional Rankean view of political history as the most important type history, that politics were decided by the leader of the nation as opposed to various social forces from below, and dismissed the claims of many younger West German historians who wished to understand political history as an extension of social history. Hillgruber and Hildebrand wrote: "The attitudes of Hitler and Stalin regarding