That Time the NSA Helped the Air Force Bomb Laos 

Surveillance agency listened for targets on the Ho Chi Minh Trail

Reports that the U.S. National Security Agency is involved in the targeting process for drone strikes is not necessarily surprising given the surveillance organization’s history. The Department of Defense refers to NSA as a “combat support agency,” and it has been very much involved in tactical operations since its inception in 1951.

The NSA has always had a close relationship with the cryptologic components of the U.S. armed forces. During the 1960s and 1970s, the NSA—working with service components like the Army Security Agency and the Air Force Security Service—monitored communications all over Southeast Asia.

The NSA also assisted in “airborne radio direction finding”—basically, locating the enemy by his radio signals and also collecting data using those signals.

By 1960, ARDF was hardly a new concept, having been used to some effect by the Germans during World War II. The U.S. military had also done radio direction finding during the world war and in Korea. After Korea, however, America’s interest in the technique quickly faded.

An official Air Force history of the ARDF effort in Southeast Asia credits Col. James S. Novy, on assignment to the NSA in the 1960s, as making “vigorous efforts to arouse USAF interest in [ARDF’s] potential.” The Air Force deployed its first specially configured ARDF aircraft to South Vietnam in the spring of 1964.

The EC-47 aircraft were specially modified World War II-era transports fitted with specialized gear for their new intelligence gathering mission. Personnel from the Air Force Security Service were on board to operate the equipment. Their job was so secret that only the aircraft’s navigator, who had to work directly with them, was cleared to know what they were doing.

A basic diagram showing the interior of the EC-47 in Combat Cross Zulu configuration. The two shaded ‘Z consoles’ contained additional equipment to collect and record enemy communications. Air Force photo

In addition to the ARDF equipment, the aircraft were also eventually equipped to communicate with other units in real time. At least once, timely information from an Air Force EC-47 reportedly prevented an ambush.

By 1968, Military Assistance Command-Vietnam was hosting weekly meetings to discuss potential radio targets and their relative priority. These requirements would then be sent to the ARDF Coordination Center and eventually make their way to Army and Air Force units actually charged with flying the missions.

Present at these meetings were both NSA officials and so-called “Controlled American Source” personnel. These were members of the Central Intelligence Agency who were running agents in places like neighboring Laos.

The U.S. had a strong interest in Laos given that the North Vietnamese had been making use of the country to smuggle men and materiel south. However, it was technically neutral in the greater conflict, making it difficult to disrupt this supply line, known as the Ho Chi Minh Trail.

The Air Force and Navy had been conducting a sustained—and secret—bombing campaign in the country since 1964. However, much of the border area between Laos and Vietnam is under thick, triple-canopy jungle, which makes air strikes difficult.

Initially, the Air Force tried to direct aircraft to their targets using radar. While this meant the aircraft could reliably drop their bombs at a specific location, it did not help in determining whether that location actually had any actual significance.

Map of Southeast Asia broken into areas for ARDF operations, as determined by Military Assistance Command. EC-47s did not conduct operations in all areas. Air Force photo

Agents and other teams, collectively known as “trail watchers,” were supposed to help with this. They could place homing beacons or directly communicate with aircraft. But with so little direct interaction with their handlers, they could also easily be compromised, chased off or killed—or be too afraid of any of those potential outcomes to reliably perform their mission.

Enter ARDF. By tracking radio communications, the enemy could effectively serve as the homing beacon for strike aircraft. After originally flying from bases in South Vietnam, the Air Force sent EC-47s to Thailand in 1969 specifically to support the ongoing bombing campaign in Laos.

North Vietnamese air defenses limited the effectiveness of the old propeller engined aircraft in Laos, however. Less than 15 percent of all EC-47 missions flown after July 1968 were over Laos.

Still, EC-47s continued to provide real-time intelligence in support of operations in South Vietnam until the U.S. withdrawal in 1973. The Air Force described them as “one of the vital elements in ground operations.” Some of the old planes eventually transferred to the Vietnamese air force.

NSA cooperation with the services during the bombing campaign over Laos is just one example of that agency being closely involved in the targeting process for air strikes. There are no doubt others.

The surveillance agency’s involvement in recent drone strikes seems like a logical evolution of these existing activities. This doesn’t make the drone or surveillance programs any less controversial, of course.

Sign up for a daily War is Boring email update here. Subscribe to WIB’s RSS feed here and follow the main page here.