A cryptologic intelligence agency of the United States Department of Defense responsible for the collection and analysis of foreign communications and foreign signals intelligence (SIGINT), as well as protecting U.S. government communications.

NSA was created out of necessity for centralizing control and coordination of the collection and processing of Communications Intelligence (COMINT). The NSA was authorized in a classified letter by President Harry S. Truman in June 1952, and formally established through a revision of National Security Council Intelligence Directive (NSCID) 9 on October 24 ,1952.

The NSA has been a controversial agency since its formation during the Cold War. During the Cold War years many feared the leaking of secrets to the Soviet Union after two agents defected. More recently the NSA has been under fire after accusations of spying on citizens both domestic and abroad through phone calls and internet records have risen.