Ideological competition

Nazism and communism emerged as two serious contenders for power in Germany after the First World War, particularly as the Weimar Republic became increasingly unstable. What became the Nazi movement arose out of resistance to the Bolshevik-inspired insurgencies that occurred in Germany in the aftermath of the First World War. The Russian Revolution of 1917 caused a great deal of excitement and interest in the Leninist version of Marxism and caused many socialists to adopt revolutionary principles. The Spartacist uprising in Berlin and the Bavarian Soviet Republic in 1919 were both manifestations of this. The Freikorps, a loosely organized paramilitary group (essentially a militia of former World War I soldiers) was used to crush both these uprisings and many leaders of the Freikorps, including Ernst Röhm, later became leaders in the Nazi Party. After Mussolini's fascists took power in Italy in 1922, fascism presented itself as a realistic option for opposing communism, particularly given Mussolini's success in crushing the communist and anarchist movements that had destabilized Italy with a wave of strikes and factory occupations after the First World War. Fascist parties formed in numerous European countries.
Many historians, such as Ian Kershaw and Joachim Fest, argue that Hitler's Nazis were one of numerous nationalist and increasingly fascistic groups that existed in Germany and contended for leadership of the anti-communist movement and, eventually, of the German state. Further, they assert that fascism and its German variant, National Socialism, became the successful challengers to communism because they were able to both appeal to the establishment as a bulwark against Bolshevism and appeal to the working class base, particularly the growing underclass of unemployed and unemployable and growingly impoverished middle class elements who were becoming declassed (denounced as the lumpenproletariat). The Nazis' use of pro-labor rhetoric appealed to those disaffected with capitalism by promoting the limiting of profits, the abolishing of rents and the increasing of social benefits (only for Germans) while simultaneously presenting a political and economic model that divested "Soviet socialism" of elements that were dangerous to capitalism, such as the concept of class struggle, "the dictatorship of the proletariat" or worker control of the means of production. Thus, Nazism's populism, anti-communism and anti-capitalism helped it become more powerful and popular than traditional conservative parties, like the DNVP. For the above reasons, particularly the fact that Nazis and communists fought each other (often violently) during most of their existence, nazism and communism are commonly seen as opposite extremes on the political spectrum. Nevertheless, this view is not without its challengers. Several political theorists and economists, primarily those associated with the Austrian school, argue that nazism, Soviet communism and other totalitarian ideologies share a common underpinning in socialism and collectivism.
The simplicity of Nazi rhetoric, campaigns, and ideology also made its conservative allies underestimate its strength, and its ability to govern or even to last as a political party. Michael Mann defined fascism as a "transcendent and cleansing nation statism through paramilitarism", with "transcendent" meaning that the all classes were to be abolished in order for a new, organic and pure people: all classes are abolished by transition, all "others" (an estimated two-thirds of the German population alone).

Support of anti-communists for fascism and Nazism
Various far right politicians and political parties in Europe welcomed the rise of fascism and the Nazis, out of an intense aversion towards communism. They saw Hitler as the savior of Western civilization and of capitalism against Bolshevism. During the late 1930s and the 1940s, the Nazis were supported by the Falange movement in Spain, and by political and military figures who formed the government of Vichy France. The Legion of French Volunteers against Bolshevism (LVF) and other anti-Soviet fighting formations formed.