In fact, this is still happening among European soc dems today that are completely fine with supporting the far right in order to protect the US neoliberal institutions because “bad countries” like Russia has had enough.

Call me a conspiracy theorist, but I suspect a lot of the leadership of major parties in Europe (including soc dem parties) are straight up compromised by either their own national business/intelligence interests, or by the :cia: directly. There is a Cold War precedent for this kind of thing, so I don't think the idea is too far fetched.