The monograph analyses the roots of some of the most significant ethnically-based (or ethnically-worded) conflicts in Europe, defines their participants' rationales, and answers the question of how they relate to the issue of European security. It is based on two case studies, former Yugoslavia and Bulgaria. Since the question of secession and self-determination is not that clearcut, the author analyses this ambiguity and examines the options. He discusses the impact of the Balkan crisis on international relations and attempts to go beyond regional security issues and to put the problem of Balkan security into a broader European perspective. This includes addressing the question as to whether NATO membership is the only solution to Eastern Europe's security concerns. In the last chapter the idea of a regional defense structure is analysed.