The author is Terry Martin of Harvard, and the subtitle is Nations and Nationalism in the Soviet Union, 1923-1939. This is an excellent book for understanding how some of the current Russia vs. Ukraine issues are rooted in Bolshevik times. Here is one excerpt:
This understanding of nationalism led Platakov to support the only apparently logical response: attack nationalism as a counterrevolutionary ideology and nationality itself as a reactionary remnant of the capitalist era. Lenin and Stalin, however, drew the exact opposite conclusion. They reason as follows. By granting the forms of nationhood, the Soviet state could split the above-class national alliance for statehood. Class divisions, then, would naturally emerge, which would allow the Soviet government to recruit proletarian and peasant support for their socialist agenda. Lenin argued that Finnish independence had intensified, not reduced, class conflict. National self-determination would have the same consequences within the Soviet Union.
As a nationalized entity, the Soviet Union can best be described as an Affirmative Action Empire…The Soviet Union was the first country in world history to establish Affirmative Action programs for national minorities, and no country has yet approached the vast scale of Soviet Affirmative Action.
The goal of course was to limit the emergence of non-Russian nationalism, not to boost the fortunes of the ethnic and national minorities themselves.