In the 1970s, Wehler became involved in a somewhat-discordant and acrimonious debate with Hildebrand and Hillgruber over the merits of both approaches to diplomatic history. Hillgruber and Hildebrand argued for the traditional "Primat der Aussenpolitik" approach with empirical research on the foreign-policy making elite, but Wehler argued for the "Primat der Innenpolitik" approach, treating diplomatic history as a sub-branch of social history with the focus on theoretical research. The two major intellectual influences Wehler cites are Karl Marx and Max Weber