The book of G.V. Lukyanov is devoted to the analysis of the situation on the eve of June 22, 1941, the understanding by the Nazi elite of the nature of the upcoming war and the assessment of the measures taken by the Soviet leaders on the basis of their extensive military-political information on preparations for fascist aggression. The author pays considerable attention to the issues of combat readiness as one of the decisive conditions for countering external aggression and the most controversial problem associated with the outbreak of the Great Patriotic War.