maybe you hate your neighbors more than you hate the exotic foreign visitor?

hmm, of course current news would rather undermine that theory, but maybe today's exotic foreign countries are about as close as neighboring countries were back in Viking times.

It's a distasteful, but relevant, aspect of vikings that they were slavers as well as raiders. If you went viking, a large part of the booty you brought back walked on two legs and had genes to pass on. Perhaps the Norse liked their neighbours just enough not to make many of them "visitors".