National Security Agency and Southeast Asia, 1954-1961

Declassified National Security Agency historical documents, prepared by NSA historian Robert Hanyok, give a new perspective on the period before large-scale U.S. operations in Southeast Asia.

They mention that Diem's security organs were given a free hand by Ordnance Number 6 of January 1956, putting anyone deemed a threat to the defense of the state and public safety," at least in house arrest. A quote from Life magazine, generally considered friendly to Diem, suggested that a substantial number of non-communists had been arrested. This is followed by a brief note, "Yet in that same process of neutralizing opposition, Diem set the seeds for his own downfall." This followed by long redactions. Both Diem and the US Military Assistance Advisory Group (MAAG), according to the NSA history, felt the communists were going into "last gasps" in late 1959.

US SIGINT support during the Vietnam War came principally from service cryptographic units, with some NSA coordination. Units still belonged to their parent service, such as the Army Security Agency and Naval Security Group. Some SIGINT personnel were assigned to covert special operations and intelligence units. There are several ways to split US SIGINT regarding Southeast Asia into periods. Gilbert's four periods are focused on the deployment of American units. In contrast, Hanyok's periods, although the redactions make it difficult to see exactly why he created chapters as he did, but it would appear that he ties them more to VC/NVA activities, as well as RVN politics, than the US view.

1960 Events in SES and organizing the SIGINT history

1960, however, opened with a "disaster for the South Vietnamese" in Tay Ninh province, followed by a number of battles lost. To SIGINT analysts at NSA, the increase in communications activity in 1960 indicated a strong growth of the communists.

In December 1960, while much text was redacted, the NSA history indicates there was major concern, about a Soviet airlift of supplies, and a "real concern that either the Soviets or the Chinese Communists, or both, would go beyond the supply flights and directly intervene in the fighting. On 14 December 1960, the NSA director, VADM Laurence L. Frost, institute a SIGINT Readiness Condition BRAVO on a theaterwide level throughout the Far East." The nature of BRAVO was not given, and the theater went back to ALPHA, apparently the lowest, by February 1961, when the intelligence community (IC) decided there was no chance the Soviets or PRC would join the fighting.

By the end of the year, NSA estimated that the number of stations had quadrupled, with the communications activity in the Saigon area growing sixfold or sevenfold. The increased communications activity, according to the history, was so striking that Allen W. Dulles, the Director of Central Intelligence and head of the intelligence community, personally went to President John F. Kennedy, in January 1961, to brief him on the increase.

South Vietnamese coups and SIGINT

A section entitled "SIGINT and the Attempted Coups against Diem, 1960-1962", opens, on 11 November 1961, with the sounds of a coup attempt in Saigon. "Diem's luck held. The coup leaders were disorganized and amateurish. Rather than seize the palace [where Diem and his brother were barricaded], they preferred to talk. They also failed to capture the radio stations and other communications centers and failed to set up roadblocks..." and other obstacles to loyalist troops, who caused the coup members to flee, often to Cambodia. "American SIGINT had been surprised by the coup, as had American intelligence in general. In the coup's aftermath, SIGINT discovered, through decrypted VC regional headquarters messages, that the communists were taking an active interest in the failed coup, learning valuable lessons from its shortcomings, which would translate into plans to take advantage of any future maneuvers against Diem.

Intercepts also made it clear that the attempted coup by paratroopers had surprised the Communists as much as Diem. "In the mad scramble for positioning that followed, the Viet Cong in the Nam Bo [Saigon] region directed subordinate elements to help soldiers, officers and others (politicians and security personnel) involved in the coup to escape." This was followed by long redactions, and then the question, "Were the Communists on to something? There is no doubt that they were correct in their assessment that the Americans were disillusioned with Diem's failure to select a course of social reform and stick with it." They believed the Americans were contacting dissidents and planning new coups, but NSA states there was no evidence of American involvement; the South Vietnamese were more than capable of planning their own.

1960 gloom: RVN defeats and concern about Soviet escalation in Southeast Asia

1960, however, opened with a "disaster or the South Vietnamese" in Tay Ninh province, followed by a number of battles lost. There was a strong increase in communications activity in 1960 and 1961, indicating an internal buildup. Added to the local activity was a fear of external intervention.

In December 1960, while much text was redacted, the NSA history indicates there was major concern, about a Soviet airlift of supplies, and a "real concern that either the Soviets or the Chinese Communists, or both, would go beyond the supply flights and directly intervene in the fighting. On 14 December 1960, the NSA director, VADM Laurence L. Frost, institute a SIGINT Readiness Condition BRAVO on a theaterwide level throughout the Far East." The nature of BRAVO was not given, and the theater went back to ALPHA, apparently the lowest, by February 1961, when the intelligence community (IC) decided there was no chance the Soviets or PRC would join the fighting.

By the end of the year, NSA estimated that the number of stations had quadrupled, with the communications activity in the Saigon area growing sixfold or sevenfold. The increased communications activity, according to the history, was so striking that Allen W. Dulles, the Director of Central Intelligence and head of the intelligence community, personally went to President John F. Kennedy, in January 1961, to brief him on the increase.

SIGINT and Building the Ho Chi Minh Trail (1959)

Hanyok writes that the 559th was variously known as a Transportation Group, Division, or Regiment. It had two subordinate regiments, the 70th and 71st, composed of truck, roadbuilding, and other operational functions. The 559th itself was subordinated to the General Directorate Rear Services (GDRS). From the SIGINT standpoint, the Trail began at two major supply-heads, Vinh Linh and Dong Hoi, which were the intermediate headquarters running the infiltration-associated radio nets from 1959 until late 1963. They disappeared in September 1963, although Vinh Linh became the headquarters of the 559th.

US Deployment and Casualty (1960)

The 3rd RRU soon had its first casualty, SP4 James T. Davis, killed in an ambush. Soon, it was realized that thick jungle made tactical ground collection exceptionally dangerous, and direction-finding moved principally to aircraft platforms.

Multinational SIGINT planning, 1961

In January 1961, while the Vietnam embassy and military group prepared a counterinsurgency plan, the SIGINT community did its own planning. The first review of the situation assumed limited support to the ARVN COMINT teams. Essentially, the policy was that the South Vietnamese would be trained in basic direction finding using "known or derived" technical information, but, for security reasons, COMINT that involved more sophisticated analysis would not be shared. It was also felt that for at least the near term, ARVN COMINT could not provide meaningful support, and the question was presented, to the State Department, if it was politically feasible to have US direction-finding teams operate inside South Vietnam. The March 1961 plan included both tactical support and a strategic COMINT mission collection NVA data for NSA.

Significant events, 1959-1963. Hanyok is the source above the years and Gilbert below them.

Eventually, the idea was that the South Vietnamese could intercept, but send the raw material to the US units for analysis. Two plans were created, WHITEBIRCH to increase US capability throughout the region but emphasizing South Vietnam, and SABERTOOTH to train ARVN personnel in basic COMINT. Concerns over ARVN security limited the information given them to non-codeword SECRET information. The first step in WHITEBIRCH was the 400th ASA Special Operations Unit (Provisional), operating under the cover name of the 3rd Radio Research Unit (RRU).