This chapter addresses the phenomenon of East European nationalism in its various forms and the security implications thereof not only for the Soviet Union, but also the United States and North Atlantic Treaty Organization (NATO). During the 1960s and 1970s, nationalism in its various forms reappeared as a major factor in the political systems of Eastern Europe, with profound implications for developments in each state, the region as a whole, relations between these political entities and the regional hegemon, the Soviet Union, and ultimately the United States and NATO. Furthermore, socioeconomic development in Eastern Europe during the period of Stalinism tended to emphasize autarky rather than integration. In the post-Stalin era, the socioeconomic infrastructure therefore existed for the revitalized nationalists and domesticists in the political leaderships to utilize in their quest for legitimacy in the masses and the societal elites. The Soviet leaders will pressure the East Europeans to shoulder part of the burden of Soviet economic stress.