Psychological Operations

History
The CIA almost immediately began psyop work after its inception in September 1947. "December 19, 1947... a top secret appendix to [the NSC-4 directive], NSC-4A, instructed the director of Central Intelligence to undertake “covert psychological activities” in support of American anti-Communist policies... the first formal postwar authorization for clandestine operations. Superseded in June 1948 by a new- and more explicit- directive drafted by George Kennan, NSC-10/2, these were the documents which piloted American intelligence into the choppy waters of secret political warfare for decades to come." NSC-10/2 created the group soon known as the Office of Policy Coordination, or OPC

UK
The UK had the Information Research Department, a part of the foreign office founded in February 1948

Saunders, Frances: The Cultural Cold War