I, a Serb, once defended a Croatian friend from another Serb. It was the only time I've witnessed a Serb being a complete jack ass towards a Croat in Chicago. I've seen the reverse far too often my whole life.
It was here in Chicago at a huge Serbian picnic in Grant Park. There was a maniac Serb from New York City at the picnic that had a tattoo of Arkan on his forearm. Someone told him that my buddy was Croatian and he came up to our little group and very menacingly told my friend he wasn't welcome at the picnic. I told him he should take his ass back to New York because Serbs and Croats get along fine in our old neighborhood (the South East Side of Chicago). He explained how he was the only Serb in a neighborhood full of Croats in New York and was regularly harassed by Croats. He eventually backed down and moved along quietly.
Sometimes being a big scary looking south side Serb has its benefits :-)
All ‘Sout’ siders are scary, big “Bhurle” bastards... :-D