Hemingway worked for both the Soviet and US Intelligence

Certain Soviet records accessed later reveal that Ernest Hemingway agreed to be recruited by the NKVD, the Soviet intelligence agency that predated the KGB. Extracted from Hemingway's Soviet file, translated excerpts show that he was given the code name "Argo" and was recruited by Jacob Golos, a top agent in the NKVD office in New York. Hemingway first came to the attention of the Soviets while covering the Spanish Civil War (1936-1939), and he may have agreed to assist the Soviets because of his strong anti-fascist beliefs. According to the Soviet files, the author did not provide any useful information but "repeatedly expressed his willingness and desire to help us." The fact was also supported by Hemingway's letters, in which he admitted to doing odd jobs for the NKVD.

Hemingway also served as a spy for the Office of Strategic Services, the predecessor to the CIA. He was recruited by the American Embassy in Havana, where Hemingway formed the "Crook Factory," an informal intelligence group. His operatives included bartenders, wharf rats, ex-bullfighters, priests, and exiled counts. His responsibilities included keeping an eye on Spanish citizens in Cuba and looking for links to Franco, Spain's fascist dictator. The agency suspected Spain of attempting to persuade Cuba to join the Axis powers. In April 1943, the Crook Factory's intelligence operation came to an end.