A short file of correspondence concerning Anglo-American intelligence cooperation during the Second World War. The letters include a complaint from the head of the Secret Intelligence Service (MI6) about the American treatment of intelligence from decrypted communications, arguing that their behaviour posed a threat to the continued availability of the intelligence, and that there was a great deal of duplicated work; and a discussion of an unexplained pre-war scheme by Franklin D. Roosevelt which it is claimed helped to avert war in 1938.