It looks like a paradox but the communists generated Nazism as a reaction. From the beginning Hitler tried to unite Nazi factions in opposition of Jewish Bolshevism. It was ridiculous but very efficient at that time. Nazis believed that the  Jews had instigated the Bolshevik revolution in Russia. They also tried to make a difference between the term socialist and the expression Marxist Socialism. The real problem for them was that the Communist Party of Germany, the famous KPD, was the largest Communist Party in the world outside the Soviet Union. All this stuff had almost nothing to do with the reality of the History. It was the creation of another fake history.  And Europe became the battlefield of the confrontation of two fake histories. The result was to create an even more complicated situation at the ideological level but also of the geopolitical level. The lack of the presence of US in Europe permitted to two totalitarian systems to try to apply their own Lebensraum. Worst they made also a strategic alliance. The Soviet Union and Nazi Germany formed a common anti-liberal front. That was the paradox of this strange situation.