All governments are authoritarian. Its a meaningless term. Its usually thrown at any state opposing the US as part of the xenophobic rhetoric used in western propoganda toward its enemies.

Lumping nazis and other fascists in with communists is a technique used to smear socialism and make nazis look less bad. Its nazi apologia

https://jewishcurrents.org/the-double-genocide-theory

China, a famously white country...

Slavs were not white historically and fascist Germany wanted to exterminate them for being inferior