The book is devoted to answering three key questions: what, when and why went wrong, due to what reasons and circumstances the progressive dynamics of social development changed at the turn of the 1960s–70s. on a destructive trajectory? Based on a cross-analysis of inaccessible sources of Western and Russian archives, memoirs and his own memoirs, the author offers his version of the deep processes of the last quarter of the 20th century, which eventually led to the impending systemic, political, economic, cultural, environmental and technological crises.