The NSA Has its Roots In the Korean War
When they put up a new communications grid and encryption methodology, the new communications by the Soviets were transmitted by cable which cut off nearly all the radio interceptions, and what little was left was no longer able to be deciphered. In response to the changing security need, the Secretary of Defense created the Armed Forces Security Agency.
AFSA was not well implemented and was rife with institutional dysfunction. Therefore, it was not effective against the Soviets. Luckily, AFSA would prove to be very useful during the Korean War. AFSA might not have been able to intercept the Soviets but they could intercept the high-level North Korean broadcasts. The North Koreans were broadcasting all of their military operations in plaintext, with absolutely no encryption.
It was not long before the North Koreans caught on to the fact that their sensitive communications were being intercepted and they quickly developed new ciphers. The problems within the AFSA continued as they were unable to centralize communications intelligence and they failed to coordinate with civilian agencies that had similar interests.
Because AFSA needed to be successful not only for success in Korea but against the Soviets, a panel was called to investigate how the AFSA failed. The results of panel led to numerous improvements and even a redesign of the entire organization. It was then the that the AFSA officially became the National Security Agency which still operates to this day. Some would say that the NSA has become more powerful than ever and better than anyone ever thought possible at monitoring enemies of the state.