“Rootless cosmopolitans” as a phrase comes from a post-war anti-semitic campaign by Stalin, and Poland under Gomulka in the 60s also employed state-sponsored anti-semitism.
In my experience anti-semitism in many other European countries is much worse than in the UK. For example, my Polish partner has an uncle who believes Jews control all the none right-wing political parties and media.
It feels like British anti-semitism has really taken off in recent years, but maybe it’s just a case of social media amplifying something that was already there?