Oswald Spengler was one of the most important thinkers of the Weimar Republic, but very little has been published on his politics, philosophy and life, especially in the English-language.Oswald Spengler and the Politics of Decline transforms the pre-existing picture of Spengler by demonstrating how Spengler's radical opposition to liberal democracy was an unwavering facet of his thought from 1918 onwards. It adopts a completely novel approach by placing a new emphasis on his political activities and writings, and is unique in explaining the interplay between Spengler's meta-historical considerations on world history and the practical demands of Realpolitik throughout the complex discourse of German national renewal.