The Wars were 25 years ago. Balkan Boy claims to be 16. Which would make his parents about 43 right now. So they would have been about 18. But with ALL of Yugoslavia exploding in all out warfare, particularly of the urban variety, which tends to be the worst kind, I find it rather hard to believe that college courses continued placidly uninterrupted. What are they NOT telling you?
Did they participate in the horiffic events that they SAY were only engaged in by the Serbs (but were in fact engaged in by both Serbs AND Croats)? I don't know. But did they probably have some ideas that shit was happening that ought not to have been? Probably. Very few Germans were involved in the Holocaust. But most knew it was happening.
There is some moral complicity there. How much is up to G-d to decide. Certainly your father is less guilty than a man who actually raped and impregnated a Bosnian woman, and I don't accuse him of that since I was not there. But I have a hard time believing he did not know about it when I did. And I am his same age now and was then! And I live in America, which helped put an end to the mess by engaging in bombing runs over the former Yugoslavia. So don't tell me that I could know something was going on when I was an 18 year old in California that he DIDN'T know being the same age in Croatia. Maybe neither he nor your mother wish to discuss the matter, as it is painful to admit the horrors of a nation's past. Some Germans still struggle with their nation's past, as do some Japanese. The Rwandans don't like to talk much about 1994, for that matter.
And culturally, I may be an English Jew, but by virtue of being Ashkenazi, many of us, including me, ultimately find our ancestry going back to Mediaeval Germany, and from THERE to the Levant (the region where Israel is). But after leaving the Levant, many of us made our homes in Germany for as long as 1000 years. The Holocaust was unbelievable to us, as much as Bosnian rape camps are to you.
So relax.Everyone's homeland fucks with their head at some point.