The origins of nihilism have been studied by such seminal figures as Franz Borkenau, George Orwell, Hannah Arendt and Eric Voegelin. Borkenau observed that Bolshevik and Nazi oligarchies were akin to a "religious order of professional revolutionaries" (cited in Erika Gottlieb, "The Orwell Conundrum", 1992, p.108) Their Messianic faith in the perfection of their political philosophy removed all moral constraints from using state power to kill those who did not share it. Orwell argued that totalitarianism stemmed from the failure of modern societies to replace religious morality with a socialist-humanist one. Instead, Orwell argued, these societies (in which he included Britain and the US) were obsessed with "orthodoxies" which made them indifferent to mass murder. Obedience to systems became an excuse to cast aside one's conscience and humanity in pursuit of conformity to a political utopia.
Orwell's view was similar to Hannah Arendt's argument, in the "Origins of Totalitarianism" (1951), that recourse to the "laws of nature" (Nazism) or "laws of history" (Marxism) gave a charismatic leader unlimited arbitrary destructive power, because he could claim that any act of violence was historically necessary. Liberal or religious qualms about mass killing could thus be dismissed as irrational or sentimental. Eric Voegelin echoed this view in his concept of 'radical alienation', or 'deculturation', defined as "a sort of apocalyptic construction by which all past history is thrown out as more or less irrelevant..." Voegelin went a step further, however, by arguing that totalitarianism is a form of gnosticism that seeks to "immanentize the eschaton"; i.e. to create utopia, redemption and salvation in this life rather than the afterlife. This utopianism, especially when placed in a Manichean political context in which two potential utopias are fighting against each other, creates the potential for unlimited slaughter and genocide because any group that is viewed as a barrier to utopia (Jews, 'the bourgeoisie', 'infidels', Communists) is now, not only 'polluting the body politic', but preventing that body from fulfilling its destiny.
These political theorists can therefore point to common causative features of genocidal potentials in Hitlerism, Maoism and Stalinism; but what about the features that made Nazism more systematic and universal in its genocidal killing than the others?
I would argue that two points stand out. Firstly, under Communism, ultra-conservative western imperialism, ultra-Zionism or radical Islam, the blockage to utopia is a rival ideology or system. It is not placed in a biological system in which the body of every political opponent must be exterminated, including the possibility of future generations. Thus it was only the Nazis whose ideology led them to insist that:
The possible final remnant will, since it will undoubtedly consist of the most resistant portion, have to be treated accordingly, because it is the product of natural selection and would, if released, act as a the seed of a new Jewish revival (see the experience of history.)Secondly, Nazism took more risks with its own survival in order to carry out an all-or-nothing war of extermination. This was racist paranoia gone berserk. There was no need to take on Stalin (who had purged his officer corps) in 1941. Stalin and Mao did not take reckless risks in order to export their revolutions. They believed that the global historical laws of Marxist-Leninism would work themselves out over generations. Hitler, by contrast, believed that he had to be pre-emptive and risk the entire German state and economy in an all-out gamble for supremacy.
This, in turn, can be explained by the Nazi obsession with biology and Pollution. The Nazis could not live with a Cold War in which Superpowers faced off for decades. Their eschatology was more urgent and required a more immediate return. Nazism could not defer political and religious gratification. Hitler's greater intensity of genocidal impulse, generated by a more intense eschatology and racism than was felt by Stalin and Mao, created a short-termism and addiction to reckless gambling that they never shared. This is why they lived a natural lifespan and he did not.