Well, Hitler took his ideas from Western colonialism, and particularly from American apartheid. The first gas chambers were an innovation by the French in their prosecution of the Haitian revolution. The methods of subjugating populations and turning them into productive contributors to the war efforts were developed by the UK, France, Spain, etc.

It’s not like the Western imperialists opposed Hitler. They just didn’t think he would invade them. They though he was going to deal with those uppity communists and return the continent back to the same and rational liberalism that allowed the bourgeoisie to flourish.

You need to do some more reading. Western colonialism is the dominant reality of the last 600 years for over 80% of the world’s population