The article deals with the fateful events of 1920—1921, which for many decades determined the fate of Mongolia and its connection with our country. In the literature, views of these events have become widespread as a democratic revolution or as an export of the revolution, motivated by the desire to make Mongolia a springboard for the world revolution. Relying on the literature on the history of Mongolia of this period, archival sources, the author shows that the motives of the communist leadership in relation to Mongolia are dictated not by thoughts about the world revolution, but primarily by state interests: protecting the border from raids, normalizing relations with China, etc. The very decision to march on Urga was motivated by military and state-political arguments, which is confirmed by the key debates in the Far Eastern leaders on May 31 — June 1, 1921, the protocol of which is analyzed by the author. At the same time, the long-term deployment of troops to Mongolia was largely driven by the initiatives of the MPP, associated with the ruling elite of Mongolia, aimed at using Russia as a counterweight to Chinese expansion. Despite the fact that the left wing of the MPP quickly mastered the revolutionary and even communist rhetoric, the real revolution in Mongolia in 1921 did not happen. In relation to the period of 1921—1928, we can talk about early modernizing reforms, the beginning of nation-building based on external support.