In late 1960, in response to the Laotian crisis, a special TDY team of four civilian intercept operators and one traffic analyst from NSA had arrived at Clark Air Base to assist in developing the Vietnamese mission, but it could only foster an improvement at the site for the duration of their visit.

One solution was to send civilian analysts from the NSA office responsible for Southeast Asia (known then as ACOM, soon to become B Group) as technical advisors to the field sites. In fact, in May 1961 there was a civilian analyst from NSA stationed in the Philippines to help there. When technical problems at Tan Son Nhut were discovered as well, a meeting was held amongst the NSA representative, Philippines, and NSA personnel at Clark Air Base to decide how to fix the shortcomings. The decision was made to consolidate the analytic and reporting missions from both sites at Saigon, giving the “front end” of the SIGINT mission, that is the field site in Vietnam, the wherewithal to carry out its work. Part of the plan called for the NSA civilian. [ — ] detailed to the ASA site at Clark, to go along to Tan Son Nhut and oversee SIGINT operations there.

This first civilian tour in Saigon lasted about six months. However, it set the precedent for the entire period of the American cryptologic presence in Vietnam: NSA civilians would retain a critical position at virtually all field sites involved in supporting the war, including those in Thailand and the Philippines. Known familiarly to the military personnel as “tech reps,” these civilians often provided the technical continuity at military field sites which were frequently victimized by the rapid and complete turnover caused by MACV’s decision to hold military tours in Southeast Asia to one year. This was especially true after the big communist signal of interest (SOl) change which crested in April 1962 when it was discovered that the ASA site at Tan Son Nhut had missed obvious signs of it, as well as significant message relay activity suggesting that communist units were redeploying into South Vietnam from Laos.

As the cryptologic presence increased within South Vietnam, there was more pressure from the Saigon command for maximizing its effectiveness. The impetus for this started in October 1961, when General Maxwell Taylor (as chairman of the JCS) visited Saigon. He reviewed the current intelligence structure, including that of SIGINT, and strongly recommended that all U.S. intelligence activities in Saigon be centralized in a Joint Intelligence Center (JIC). He also added that the JIC should be integrated to some degree with a similar ARVN center. He added that all efforts should be made to assure that this proposed center have access to all timely information.

Featured image: Flag of the South Vietnamese army.  Founded December 30, 1955 and disbanded on  April 30, 1975.

Source: Spartans in darkness: American SIGINT and the Indochina War, 1945-1975