Nationalism vs Yugoslavism

For the second time this century, a problem involving the South Slavs threatens to provoke a general European war. Unlike the crisis of July 1914, however, today's conflict in the former Yugoslavia is a purely fratricidal affair. To the outside observer there seems little to distinguished Serb from Croat, or either side from their mutual victims, the Bosnian Muslims. All three parties to the dispute speak the same language, in some areas even the same dialect or sub-dialect. Why, then, is the fighting so bitter, the intolerance so deep-rooted and absolute?