Not to the exclusion of other peoples, you can find plenty of gleeful posts about the brutal deaths of Russians and Chinese, or just simply mocking their societies/industries, at any given time on at least three boards, off the top of my head.
It's a glowie/shill cesspool, not at all authentic.
I found some great friends from 4chan -> IRC channels, we all fell away eventually, but it was a good 15 years of my life.
Now I couldn't even imagine taking to these people. I don't think it's just because I'm older, either.
And I'm only taking about gee
There is literally dedicated anti-Russian thread (/uhg/) on /pol/ and also plenty of anti-Chinese sentiment all over the board, I don't think day can pass without someone making fun of Changs and Zhangs.
Otherwise it's more balanced. /pol/ has both /uhg/ (Ukrainian Happening General; mostly pro Ukraine) and /chug/ (Comfy Happening in Ukraine General; pro Russian). /chug/ as its name implies is more comfy and has anime girls. /uhg/ is quite nasty and mostly posts gore of Russian soldiers.
https://boards.4chan.org/pol/thread/442998412
(NSFW obviously)
You can post memes about beheading Chinese people on 4chan and no one will bat an eye.