National Intelligence Authority

The National Intelligence Authority (NIA) was the United States Government authority responsible for monitoring the Central Intelligence Group (CIG), the successor intelligence agency of the Office of Strategic Services established by President Harry S. Truman's presidential directive of 22 January 1946 in the aftermath of World War II. The National Intelligence Authority and Central Intelligence Group were both replaced respectively by the National Security Council and the Central Intelligence Agency under the National Security Act of 1947, which was implemented on 18 September 1947.