In February 1962, General Paul Harkins arrived in Saigon to take charge of the American effort. The advisory group’s command relationship was altered to reflect a growing strategic interest in Vietnam on the part of Washington. Harkins assumed command as the senior U.S. officer in Vietnam, Commander United States Military Assistance Command, Vietnam (COMUSMACV), directly subordinate to the Commander-in-Chief Pacific (CINCPAC). MACV was now the headquarters of a military command, while the former assistance group, MAAG, remained, but it had become a subordinate element under Harkins’ control. [ — ]

Meanwhile, following General Taylor’s recommendations, a way was sought to maximize the efficiency of the military’s cryptologic effort. The separate missions of the ASA, the AFSS, and the marine contingent, as well as the Sabertooth training program, all required better administration and coordination. For some time, NSA had gotten by with rotating civilian overseers through Saigon on temporary duty (TDY) missions, but these simply had failed to keep NSA officials informed of what was happening.  Besides that, the responsible DIRNSA representative, NSAPAC, located in Tokyo, was too far removed from Saigon to take effective action.

So, a new position was established in Saigon – the NSAPAC representative, Vietnam (NRV), originally referred to as the NSAPAC representative Southeast Asia. [ — ] The NRV’s major job was to facilitate support to COMUSMACV and its subordinate commands by coordinating the disparate and far-flung SIGINT operations, as well as keeping DIRNSA informed as to what NSA technical support was needed for the military elements already in place [ — ] who had served previously in liaison roles for the ASA and AFSA, arrived in Saigon in April of 1962 to be the first NRV.

However, [ — ] impending arrival created a cloud of controversy. Originally, the NSA representative was supposed to have been allocated office space and living quarters, a request which provoked a nasty reaction from the commander-in-chief Pacific, Admiral Harry Felt, who interpreted these requests as “preferential treatment.” At the same time, Felt was known not to like liaison personnel.

However, CINCPAC’s animus against liaison types was not the only problem with which [ — ] had to contend. A far more contentious one developed around a plan that

NSA had developed for organizing all SIGINT resources in the region under its direct control. Besides functioning as the NRV, he was also supposed to wear the hat of the chief of the proposed Joint SIGINT Activity (JSA), Saigon. The JSA had been put forward as DIRNSA’s way of exercising direct operational and technical control of all SIGINT resources in South Vietnam and [ — ] The JSA would work directly with COMUSMACV staff, receiving requirements from the latter and then tasking the appropriate in country SIGINT resources.

This plan had its advantages, principally the centralization of resources, as well as a concrete demonstration to CINCPAC and COMUSMACV\that NSA was serious in making an “all-out response” to/the need for timely SIGINT support in Vietnam. However, NSA knew that the JSA would be a hard sell to the military, especially the AFSS and ASA, the latter of which was already carrying the brunt of the cryptologic load in Vietnam. Another potential difficulty was that the JSA threatened to swallow up the already thin layer of available target expertise from the intercept sites.

[ — ] The trouble was that no one seemed to want the responsibility of running the entire SIGINT program in Southeast Asia. In April and May, the incumbent DIRNSA, Vice Admiral Laurence H. Frost, traveled throughout the Far East on a tour of sites and supported commands. He attempted to enlist either CINCPAC (Admiral Felt) or COMUSMACV (General Harkins) to take operational control of the SIGINT units in the region, but both demurred, preferring that the units Improve their performance rather than reorganize their structure.

In the end, the road taken reflected a desire to please all of the participants, Rather than name a central authority for all SIGINT activities in Southeast. Asia, a compromise was reached in which authority was divided up amongst the principals, The commander USASA was appointed: executive agent for second echelon reporting on all communist communications in the region with the Philippines site acting as the senior reporting center. The Philippines also absorbed first echelon reporting responsibilities from all the sites subordinate to it. The ASA commander also was to be the host service for all collocated SIGINT facilities in the region. [ — ] The USAFSS and NAVSECGRU sites would perform their own first echelon reporting, but would accept tasking from NSA.  Meanwhile, the role of NRV would be to coordinate and support the military sites and reporting centers, while acting as a technical base for reporting from the ASA mission in the Philippines.

Ultimately, this this solution never solved the lingering need for centralized control, while, at the same time, the experience with the JSA plan left many military commanders suspicious of the desire by NSA to control all SIGINT resources in the region. The struggle for control of SIGINT assets would continue throughout the war and surface again in 1970 when the JCS would try to redefine the doctrine and mission of certain tactical SIGINT assets to get them away from NSA’s control.

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