The aim of this paper is to show how, at the height of the Cold War, the British intelligence services responded to the new spy system created by the Comintern developing a secret campaign of political and cultural propaganda, under the cover of prestigious foundations to channel intellectuals in defense of a liberal democracy. This spy system expected to carry out propaganda secret operations and manipulate the intellectuals from almost the very beginning of the Soviet Revolution. The keystone to win the battle of consciences was the Congress for Cultural Freedom and its editorials, magazines, exhibitions, scholarships, concerts, congresses and conferences. Finally, it will be noted how the Congress for Cultural Freedom implemented the political conception of "non-communist left" to sustain the social democracy in the Western bloc.