Another bit I find interesting about Hitler's point of view on the "untermenschen":

Dr. Todt (German engineer and senior "Nazi" figure) says, "They can endure everything, including the harshness of climate. We are too sensitive and are bound to be defeated. In the end the victory will go to the Russians..."

Speer says, "Hitler too, obviously influenced by Spengler, had expressed similar ideas in peacetime when he spoke of the biological superiority of the 'Siberians and Russians'. But when the campaign in the east began, he thrust aside his own thesis, for it ran counter to his plans".
That reminds me of Hitlers reaction to proposals to ship the Jews to siberia to die in the camps instead of being just murdered .
The harsh conditions would weed out the weak and they would be left facing a race of superjews in the future .