Divini Redemptoris §17

¹⁷ There is another explanation for the rapid diffusion of the Communistic ideas now seeping into every nation, great and small, advanced and backward, so that no corner of the earth is free from them. This explanation is to be found in a propaganda so truly diabolical that the world has perhaps never witnessed its like before. It is directed from one common center. It is shrewdly adapted to the varying conditions of diverse peoples. It has at its disposal great financial resources, gigantic organizations, international congresses, and countless trained workers. It makes use of pamphlets and reviews, of cinema, theater and radio, of schools and even universities. Little by little it penetrates into all classes of the people and even reaches the better-minded groups of the community, with the result that few are aware of the poison which increasingly pervades their minds and hearts.