Forthcoming in Adam Fagan and Petr Kopecky eds. The Routledge Handbook of East European Politics. Routledge 2017 One of the earliest political visionaries of federalism in Eastern Europe,interwar Polish leader Józef Piłsudski, famously remarked to former socialist comrades that "we both took a ride on the same red tram, but while I got off at the stop marked Polish independence, you wish to travel to the station Socialism." (Macmillan, 2002: 208) Piłsudski's modernising vision of an intermarum (międzymorze) federation of republics under Polish hegemony from the Baltic to the Black Sea, acting as a bulwark against Russia, failed to overcome the power of nationalist particularism (Snyder, 2003) Among the many paradoxes of communism in Eastern Europe is that many socialist and communist internationalists were transformed over time into nationalists. In certain countries with multinational societies, especially the Soviet Union, great efforts were made by the ruling communist parties to recognise the political importance of national and ethnic cleavages, in the process compromising the internationalist tenets of communist ideology and its paramount attention to class-based cleavages. Although many of the nine states that formerly made up communist Eastern Europe prior to 1991 were significantly multinational in character, six were unitary states and only three were federal. One of the six unitary states-the German Democratic Republic (GDR)-was absorbed by a mutually agreed treaty into a unified federal Germany in 1990 (though without the referendum required by the German Constitution of 1949). In countries such as the Soviet Union (USSR), Yugoslavia, and Czechoslovakia, communist parties engaged in sophisticated federal institutional engineering to recognise and embed certain national and ethnic cleavages in the organisation of state power. The three communist federal states have been generally discussed more within debates about the reasons for their systemic collapse rather than their stability over many decades, with communist federations being widely seen as being "façade" forms of federalism and otherwise unviable states because of their institutionalisation of nationalism and ethnicity. What, then, if any, is the relationship between ethnofederalism and the break-up of communist federations? The puzzle is what explains the resilience of communist federations over many decades, their breakdown in the late 1980s and early 1990s in three cases, the postcommunist survival and durability of federalism in Russia, and the continuing attraction of the concept as a conflict management device in the wider region (for example, in Russia and Bosnia and Herzegovina). Federalism under Communism Communist federations were constructed following the Russian model on the basis of a Stalinist paradox which attempted to reconcile Marxism and nationalism. Stalin had spoken in 1934 of a Marxist formula with regard to cultures: that they should be "socialist in content and national in form" with the ultimate aim of building a common ...