After working as a journalist for the Norddeutsche Allgemeine Zeitung, a semi-official newspaper, he joined the press section of the German Foreign Office in 1907 and attracted the attention of Wilhelm II.
[2] In October 1917 he was posted to the German embassy in Stockholm to arrange a cease-fire on the Eastern Front, and then to Moscow as the top aide to Germany's ambassador to Russia, Count Wilhelm von Mirbach.
He joined the German Democratic Party, contributed regularly to the pro-Weimar newspaper Die Deutsche Nation, and served as the Foreign Office's representative during the drafting of the Weimar Constitution.
[5] In 1927 he was named Kurator of the University of Frankfurt, to which he attracted a distinguished faculty that included Ernst Kantorowicz, Adolph Lowe, Karl Mannheim, Paul Tillich, and Max Wertheimer.
In 1929 Riezler sided with Martin Heidegger during the famous "Davos encounter" with Ernst Cassirer and wrote an eyewitness account of this event, "Davoser Hochschulkurse 1929," for the Neue Zürcher Zeitung.
White (1912-1974), a New School professor of political philosophy who had been Leo Strauss's first graduate student; and his brother Walter Riezler (1878-1965), a prominent musicologist, art historian and associate of the Deutscher Werkbund.