Soviet internationalism, in its post-1934 codified form known as the Friendship of Peoples (Druzhba narodov), was the official ideology of national relations within the USSR. It claimed to have superseded "bourgeois" nationalisms by combining a federal structure of titular national republics with a single-track Communist Party and a hierarchically constructed Soviet identity. Its theoretical anchor lay in Joseph Stalin's 1913 essay Marxism and the National Question, which defined a nation by language, territory, economic life and "psychological make-up", and his 1925 formula of cultures "national in form, socialist in content".

In practice the doctrine was a moving compromise. The 1920s korenizatsiia (indigenisation) policy expanded native-language instruction, recruited national cadres, and created the territorial taxonomy of union republics, autonomous republics, autonomous oblasts and national districts in which the Caucasus was carved up by the Caucasian Bureau decision of 1921 (kavbiuro decree 1921) and the 1923 formation of the NKAO. The 1930s reversed indigenisation, reinforced Russian as the lingua franca, and prosecuted "bourgeois nationalists" in mass, including thousands of Armenian and Azerbaijani intellectuals during the Great Terror. The 1948–53 deportation of Azerbaijanis from the Armenian SSR (Stalin deportations), executed under the cover of "voluntary resettlement", showed how easily friendship-of-peoples discourse coexisted with ethnic engineering.

For the Karabakh question, Soviet internationalism functioned as a freezer rather than a thaw. NKAO Armenian petitions to Moscow in 1945, 1965 and 1977 went unanswered; the formula required nationalities to be loyal to their union republic, not to express trans-republican grievance. Glasnost broke this constraint after 1985: the 20 February 1988 NKAO Soviet vote for transfer to the Armenian SSR became the first overt rejection of the doctrine by a titular national institution since the 1920s. (sourced opinion: de Waal argues the Soviet system "did not so much resolve nationalism as preserve it on ice"; Cornell sees the Karabakh case as the direct template for subsequent post-Soviet conflicts in Abkhazia, South Ossetia and Transnistria.)