Or what is China for that matter? It is becoming clearer in some of the more astute research that the Soviet Union was not a federation, not an empire, not a colonising power, not a nation-state, but an entirely new state formation.
A federation assumes disparate groups that then slowly merge together to form a state, like the United States or Switzerland. The catch with the situation in the Soviet Union was that such disparate groups did not exist, except for a brief time after the ‘civil’ war that followed the October Revolution.
There are many still who like to apply the term ‘empire’ or ‘colonial power’ to the USSR, since these are known frameworks. Thus, it sought to impose its imperial will on subject peoples much like the tsarist autocracy that it overthrew, if not seek world domination; or it exploited the ‘border lands’ for the sake of raw material and was therefore a colonial power. But these do not get us very far. The Soviet government was extraordinarily careful to avoid replicating the patterns of the tsarist empire, which involved suppressing the many nationalities that made up the Soviet Union. Instead, they fostered the diversity of the cultures, languages and forms of governance of these nationalities (with the exception of some ‘enemy nationalities’ during the Second World War, who opted out of the project and toyed with aiding the enemy – they were, of course relocated). As for colonialism, the Soviets actually supported anti-colonial movements around the world, coming to see the October Revolution as in many respects also an anti-colonial revolution, especially among the various national groups within what became the USSR. For them, particularly the Belorussians, Latvians and Georgians, nationalism was a positive movement and was seen as one with the socialist project.
A nation-state is impossible to think now without Benedict Anderson’s ‘imagined community’ argument. But in the intense debates among socialists (German and Austrian Marxists such as Karl Kautsky, Karl Renner and Otto Bauer; the members of the Bund, the Jewish Workers Party, and the Bolsheviks) in the early twentieth century, ‘nation’ meant not the nation-state but what might now be called ‘ethnic minorities’. However, the problem with that term is that the nations in question were not predicated on ethnicity and they included both minority and majority nations. In order to get away from the traps of using the term ‘nation’, it is perhaps better to use the term ‘nationality’. Indeed, in the Chinese context, this term is still used: minzu. In light of this situation, the Soviet Union itself was not a nationality, not a nation, and not a nation-state.
So what was it? The terms they used the describe the Soviet Union are instructive. They preferred to speak of the ‘Land of the Soviets’, the ‘Soviet people’ and even the ‘Soviet Motherland’. The favoured term of the 1936 Stalin Constitution was ‘friendship of the peoples’. For Terry Martin, this was the ‘imagined community’ of the Soviet Union. But I would like to go one step further and suggest that the Soviet Union was not a nation-state but a multi-national socialist state. In this way it provides one model as to how a socialist state formation might develop. The fact that this model deeply influenced China in the 1950s also suggests that China has also developed into a multi-national state, albeit with its own inflections since then.
 Terry Martin, The Affirmative Action Empire: Nations and Nationalism in the Soviet Union, 1923-1939 (Ithaca: Cornell University Press, 2001), 15, 19, 461; Theodore R. Weeks, “Stalinism and Nationality,” Kritika: Explorations in Russian and Eurasian History 6, no. 3 (2005): 567.