Fitin also is credited with providing ample warning of the German invasion (Operation Barbarossa) of 22 June 1941 that began the German-Soviet War.

[4] Only the actual invasion saved Fitin from execution for providing the head of the NKVD, Lavrentiy Beria, with information that the General Secretary of the CPSU, Joseph Stalin did not want to believe.

In November 1944 he reported: "Despite participation by a large number of scientific organization and workers on the problem of Enormoz in the U.S., mainly known to us by agent data, their cultivation develops poorly.

Pavel Fitin reported to Vsevolod Merkulov: "Valuable information on Enormoz is coming from the London station.

In 1942, Joseph Stalin appointed Pavel Sudoplatov to head the intelligence work on the Manhattan Project, and to coordinate the data gathered by Soviet agents in England, Canada, and the United States.