The idea of multiple cultures living together being a "Jewish invention" is retarded, sure. But what's even more retarded is when you're talking about multiple cultures, non of which are Jewish.

The implications of this is that if there were no Jews, there would be no places on earth, nor would there ever be places where cultures mixed.

Jews have invented a TON of stuff, per capita way more than anyone sure ... but multiculturalism ...? That's something someone with a learning disability would say.