The roots of Johann von Leers' anti-Semitic agitation go back to the Weimar Republic, where he made a name for himself as a speaker and journalist alongside Goebbels in Berlin from 1929. In 1936 he received a call to the University of Jena to conduct "Jewish research" there. The hallmark of his boundless journalistic work in the press and on the radio was a fanatical anti-Semitism, which - looking back at the crimes of the National Socialists - makes the exclusion and extermination of the Jews appear as an irreversible consequence. After internment, illegality and flight in 1950, Johann von Leers continued to be active as a "prophet of ethnic anti-Semitism". In Buenos Aires he was one of the key players in the networks of incorrigible National Socialists. In 1956 he moved to Cairo, where he worked for anti-Israel propaganda. He also worked for the Federal Intelligence Service for a number of years. For a long time, researchers did not pay any further attention to Leers' work in the context of the anti-Semitic propaganda of the National Socialists and in the networks of the "anti-Semitic International" of the 1950s and 1960s. This book closes this gap.