I think that's just good ol' fashioned xenophobia. But yeah, has often been a trait of ultra nationalism in Europe's very complex history. Maybe the comic should be retitled; A beginner's guide to "nationalism".
I say often here, pick whatever political/economical/societal ism you like, there'll always been an entity exploiting it in the background. This is why we have so many, none of them seem to ever work, and everyone has such varying views and experiences of them, why they do/don't work. Our species can't have nice things.