The essay concentrates on Russian studies of ethnicity and identifies substantialist and relational approaches to studying ethnicity in international relations. Substantialists see the impact of ethnicity as the main organizing force of international politics and view the states as principally ethnocentric units, driven by ambitions of large ethnic groups. In their turn, relationists question these assumptions and seek to depoliticise the notion of ethnicity. Rather than concentrating on states or large ethnic groups in international politics, they take an individual as the main unit of analysis and argue that ethnicity is a choice, not a destiny. The author sees both substantialism and relationism as actively developing in Russia and associates progress in the field with further development and cross-fertilization of the two ideas.