Cryptologic involvement in Vietnam began in the earliest days of the conflict. Servicemen arrived in the early 1960s to provide support and training to the South Vietnamese. Their efforts were not without difficulties.
Numerous fixed field sites in Vietnam conducted both strategic and tactical collection missions as well as radio direction finding (DF) In fact, it was on a DF mission that the U.S. Army lost one of its first soldiers in Vietnam, SPC4 James Davis, in 1961. By 1966, the fixed sites were also doing border surveillance and infiltration interdiction along the Vietnam-Laos-Cambodia border. The Army Security Agency, the cryptologic branch of the Army, used a wide variety of aircraft as well to conduct aerial reconnaissance missions. Three Army crews lost their lives while conducting aerial signals intelligence missions in Southeast Asia.
The U.S. Navy also began its surveillance as early as 1962, conducting shore, shipborne and aerial reconnaissance. By 1964, the missions included “all-source intelligence.” They photographed items of interest on the coast and monitored coastal radar activity to provide information on Viet Cong supply routes. In August 1964, the attacks on the U.S.S. Maddox and Turner Joy were the first open conflicts between the U.S. and the North Vietnamese forces. The Vietnam War began.
Throughout the war, all military services’ cryptologic elements took part in providing tactical and strategic information to military commanders. Information derived from signals and electronic intelligence flowed quickly back to the commanders in the field. The National Security Agency also sent civilians to Vietnam to assist with the effort. They worked side by side with their military counterparts and the South Vietnamese. Those stationed at NSA in the United States worked around-the-clock processing, translating, and forwarding this vital intelligence.