The research context is the post-1945 Cultural Cold War. There is a considerable literature on the USA and its agencies, such as the Central Intelligence Agency (CIA); and to a lesser extent on the Soviet Union and agencies such as the Communist Information Bureau (Cominform). The use of the United Nations and UNESCO in this ideological struggle, using propaganda, ‘soft power’ or cultural diplomacy, exploiting the arts, sciences, and intellectual life, has been neglected. The project considers this through a critical review of secondary literature and original archival research. It clarifies and makes coherent a key issue, identifying lessons for today.