A common feature among the eight countries in the Central Asia and the South Caucasus region is the pluralistic ethnic structure that has had considerable negative impacts on not only the nation-building but the state-building processes as well. Providing a convergence theoretical framework, the paper is attempting to explore and explain the dynamics of ethnic nationalism as the most important inner challenges of the states in the region. The main assumption of this study is the incidence of the three variables of authoritative structure of the states, ultra national streams affecting the ethnic nationalism and structure of the international system while have moved the ethnic elites to mobilize politically the ethnicities and caused the initiation, evolution and continuity of the disintegrating trends in the past two decades.
            The paper concludes that the two variables of structure the international system and the trans-national streams will continue its affecting move and there would be no escape but to apply in the pluralistic societies, the political management method based on unity in multiplicity pattern in order to refrain from politicizing the ethnic phenomenon and disintegrating streams and to reform structurally the authoritative  political systems of the states in the region.