engineering evil: holocaust, page-32

"The russian communists and the nazi socialists were natural allies prior to the national socialists deciding that the Russian resources and slave labor potential was greater than their potential friendship.."

No it was a friendship of convenience. Hitler redefine what socialism

"Nazism favoured private property, freedom of contract, and promoted the creation of a national solidarity that would transcend class differences.[16][17] Nazism supported the outlawing of strikes by employees and lockouts by employers"

Nazism/fascism encourages a heirachy in society - so the masses can be exploited by the leaders (fuhrer at the top)

In practice Communist leaders get corrupted by power and don't follow the the ideals of communism/socialism

BTW I'm not a socialist by any means - more a libertarian