There’s plenty of examples of people of both nationalities living, working, cooperating, or interacting together.

“They’re all guilty” is bullshit.

Whenever I try to argue with them, they tell me that I’ve been brainwashed by “Western propaganda”.

I would ask “What makes you think so?” and go from there.

Likely the only viable way is to guide them into realizing where their biases come from, or that they’re taking views over without questioning them.

If you seemingly can’t change their opinions or views, and it burdens you, it’s fine to accept different or opposing views. You can either evade those topics completely, and if necessary be vocal and explicit about that, or physically leave [the room] if necessary, or make your opposition clear while also making it clear that you have no interest in discussing it further.