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The was view that Germany had not been defeated on the battlefield in World War I but had been brought down by liberal, socialist and Communist subversives on the home front. In other words it was claimed that 'the Jews had caused Germany's defeat in World War 1. Potentially, this made antisemitism explosive in Germany.
In much of Europe it was assumed that Jews were Communists. In many hardline right wing circles there was talk about a supposed 'Judeo-Bolshevist conspiracy'. This was highly inflammatory. Despite his ranting against Jewish businessmen Hitler saw the Jews as the 'biological root' of Bolshevism.
In Bavaria but not in other most parts of Germany a number of Marxists of Jewish origin had been prominent in the upheavals of 1918-1919. Most, like Ernst Toller and Erich Mühsam, for example, were idealistic utopians. They were not conspirators or traitors or anything of that sort. However, their origins were shamelessly exploited for propaganda purposes.
Many extreme German Nationalists (not only the Nazis) called the new German republic a 'Jewish republic' (though almost none of its leaders were Jews). There was a widespread tendency, not only in Germany, to equate the Jews with subversion and Communism. In many of his speeches Hitler often used the words Jews and Bolshevists almost interchangeably. He merged rabid anti-communism with equally fanatical antisemitism. To this he later added the claim that Jews were homosexuals, allegedly undermining the manliness and and fighting spirit of the German people.