What's your problem man? I'm Croat; does that makes me Nazi?
I voted for jewish candidate on a last elections for president of Croatia; yes, we Croats are such a Nazis that we had a jewish candidate for president. And he comes form the strongest croatian party. I'm not saying that there aren't a couple of skinheaded idiots in my country, but, every country has them. In WWII some things happened that shouldn't but you can't blame people who's parents weren't even born in those times.
The things this guy in a video said are false, you can ask every croatian Jew if you know anyone. Don't you know who Slobodan Milosevic is?
He is the only man in Europe after Hitler responsible for genocide on bosnian people and he wanted to make his own empire called Great Serbia; there are even videos on youtube where he is saying that. They didn't called him Balkanic butcher for no reason.
In my opinion, you could tell him :
1) Because somebody votes for a "Jewish" candidate does not mean they are not anti-semites. It is a well-known fact that there are lots of people who were born Jewish who defend anti-semitic views, sometimes not even realizing it. We usually call them self-hating Jews. Voting for someone who holds anti-semitic views is an anti-semitic act, even if the person you vote for was born Jewish. Actually, supporting a self-hating Jew is the best excuse and disguise for an antisemite.
Of course, the problem with this argument is that this Croat guy probably does not even realize that anti-zionism is anti-semitism, and most of the overtly anti-semitic speech in the Western world is anti-zionist...
2) There was no genocide against the Bosnians, that is a lie revealing his anti-Serb bias. There were crimes, some of them horrible, that is true, but they came as reprisals against horrific crimes committed against Serbs, and during the course of a war that was a legitimate attempt from the Serbs to protect their people and their land. This is very different from planning and carrying out the extermination of an entire people.