The paper sets up the nature problem of the anti-Soviet movement ideology in Eastern Russia in the epoch of the social and political cataclysms in 1918-1920 and its impact on the political struggle for power in the Siberian region. The purpose of the paper is to reveal the peculiarities of the anti-Soviet political factions’ ideological goals during the Civil War in Siberia and the reasons for the supporters of February Revolution to consolidate around the “white idea” of a unitary state. It was found that the anti-Soviet political bloc during the initial period of the Civil war included three main ideological movements that reflected an objective balance of socio class and political forces in Siberia. The interests of these political groups were in acute contradictions due to different understanding of the future state structure of Russia. The socialists upheld the principle of Federation, the officer-cadet groups defended the idea of a unitary state and the Siberian regionalists advocated a confederal state structure. Different ideological preferences resulted in a fierce struggle for power. In the end, the winners were the representatives of the movement, which defended the unitary state principle, marked as the «white idea». This political choice in favor of the military dictatorship of the Unitarians was backed by the fact that Siberian commercial and industrial circles and cooperators, who previously supported the regionalist movement in the anti-Soviet political bloc, fully understood the need to recreate the single Russian market. They required this to solve historical «Siberian issues» associated with overcoming the negative colonial legacy of the pre-revolutionary development of the region. The results of the study can be used when writing works on the history of Siberia, when teaching courses on the Russian history, courses on the history of the 1917 revolution and the Civil war.