An extreme reflection of the dangers confronting modern social development is the growth of racism, nationalism, and militarism and, in particular, the rise of demagogic, hypocritical, and monstrously cruel dictatorial police regimes. Foremost are the regimes of Stalin, Hitler, and Mao Tse-tung, and a number of extremely reactionary regimes in smaller countries, such as Spain, Portugal, South Africa, Greece, Albania, Haiti, and other Latin American countries.
These tragic developments have always derived from the struggle of egotistical and group interests, the struggle for unlimited power, suppression of intellectual free­dom, a spread of intellectually simplified, narrow-minded mass myths

Progress, Coexistence and Intellectual Freedom (1968) - Dangers - Police Dictatorships