It's because Russia has been demonised in USA's propaganda over decades. They're selling trying to do the same with China now, except it's more for direct commercial reasons than to protect the ideal of Capitalism as it was before.
I grew up getting a lot of "evil commies" messages in US American media and I'm not even in USA (I'm from UK).
I grew up getting a lot of "evil commies" messages in US American media and I'm not even in USA (I'm from UK).