A possible way to test the proposition that an ethnically heterogeneous polity with an illiberal regime, such as the USSR, could not be durable is to take a look at a polity with ‘opposite’ characteristics. The early United States seems to ﬁ t the description, because the conditions of (politically relevant) polyethnicity and authoritarianism were absent, and the history of its original integration did not involve violence. If one looks at some of the blueprints for reforming the USSR into a ‘real’ federation, they clearly defer to the American archetype. 1 Such proposals were underpinned by historically unwarranted presumptions about the benign stability of American federalism. Liberal-republican and voluntary, the American federal polity nonetheless split up 73 years after its establishment and was reconstituted by force. The common belief that we are dealing with a genuine federation in the American case and with a camouﬂ aged empire in the Soviet has foreclosed recognising analogies between that episode and the one that brought the Soviet Union down. It may be asked whether the USA and the USSR are really comparable, given the difference of their political regimes. The answer is that the two polities shared one crucial feature – a constitutionally embedded notion of dual sovereignty, which is not dependent on the nature of political regime. The properly Soviet aspects of the Soviet Constitution, such as the de-legitimation of private property and the leading role of the Communist Party, can be thus left aside in this discussion. Both 1861 and 1990 saw the revolt of the constituent units against the legislative precedence of the federal centre. I shall focus on this structural similarity.