MACV-SOG: Secret Operations in Vietnam

In 1964, owing to the US’ increasing number of military activities within Vietnam, US military structure underwent a marked change. Thus, the Military Assistance Command, Vietnam, Studies and Operations Group (MACV-SOG) was established in January 1964. Sometimes simply referred to as the ‘SOG’, the inconspicuously named unit was responsible for all manner of reconnaissance, special operations, and psyops in Vietnam during the Vietnam War.

The MACV-SOG Emblem
(Img; the MACV-SOG Emblem; via SOGsite)

The group was comprised of Navy SEALs, Marine Recons, Air Force Special Operations soldiers, and Army Special Forces operatives [source]. The force was above top secret – operatives swore to secrecy for over 20 years. This sadly meant that families of MACV-SOG members were not informed if their loved ones were killed in action [source].

Operational Structure

Command Control

The MACV-SOG fell under the control of the US Military Assistance Command Vietnam, the US military command offering military assistance to South Vietnam. The Military Assistance Command was a subsidiary of the US Indo-Pacific Command. The first commander of the MACV-SOG was Colonel Clyde Russell.

The MACV-SOG had headquarters in Saigon (now Ho Chi Minh City), with its subordinate units having multiple operational bases throughout Vietnam and surrounding territories [source].

However, some reports suggest that the MACV-SOG had direct instruction from the Pentagon on specific missions [source].

Subsidiary Units

In the early years of the MACV-SOG, the unit operated in smaller units under a singular command. This created a complex command structure that was difficult to maintain due to the highly varied demands of each region.

(Img; MACV-SOG Command Structure; via WikiCommons)

As the unit matured and the Vietnam war progressed, the MACV-SOG split into regional commands:

  • Command and Control North (based in Da Nang) – operated in Southern Laos and Northern Cambodia
  • Command and Control Central (Based in Kontum) – conducted similar operations as Command and Control North, by operating in Southern Laos and Northern Cambodia
  • Command and Control South (Based in Ban Me Thout) – operated exclusively in Southern Cambodia.


The equipment carried by MACV-SOG was significantly different to that of the mainstream army forces, owing to the unconventional warfare they undertook. The unit primarily carried the CAR-15 [source].

In addition, depending on mission requirements, MACV-SOG operatives also carried:

  • AK-47
  • 40mm M79 – often modified to reduce weight
  • V-22 grenades
  • M-26 fragmentation grenades
  • Claymore Mines

During the early years of the Vietnam war, the US denied it had any troops operating outside of South Vietnam. As a result, SOG operators wore sterilised uniforms and carried weaponry without serial numbers to avoid detection [source]. This is also a contributing reason for MACV-SOG operators to also use captured AK-47s, RPKs, and RPDs.

MACV-SOG also dabbled in experimental weaponry. The “Gyrojet” pistol was a firearm that fired miniature rockets, dubbed “Microjets”, instead of bullets that gyroscopically kept the bullet in balance. It was surprising light and transportable and in turn was known to be used by the unit. (Source)

MACV-SOG operators also had an affinity for captured weaponry and fitting it to their needs in combat. The RPD was a popular LMG that when captured would be “chopped.” In shortening the barrels MACV-SOG units saw increased mobility, and allowed them to continue fighting with captured enemy ammunition in the field.

Notable Operations

Although much of the details of MACV-SOG operations remain classified, the MACV-SOG undertook numerous reconnaissance missions across borders. Many of these missions were the most dangerous and sensitive of any covert action undertaken during the time.

For example, OP-35, the ‘Ground Studies’ group of MACV-SOG, undertook hundreds of cross-border operations between 1966 and 1972 [source]. It is believed that OP-35 had a force of up to 2,500 US personnel and 8,000 indigenous troops [source], segmented into smaller teams as small as 10 men. These tended to include a mixture of US Green Beret troops, specialised in unconventional warfare, as well as local war fighters. These indigenous troops, colloquially known as “little people”, came from multiple regional countries such as China, Cambodia, and South Vietnam [source]. Indigenous people were key to the SOG’s success. This is because they brought a wealth of intelligence surrounding local geography, language, and culture.

OP-35 Personnel, SubUnit of MACV-SOG
(Img; OP-35 Personnel, SubUnit of MACV-SOG; via

Operation 34A

Operation 34A began in 1961. This highly classified CIA operation was a string of largely unsuccessful covert attacks in North Vietnam. These failed missions, comprised of both air and naval infiltration, led to loss of life for personnel entering via parachute and boat.

To increase the chances of success, Operation 34A was transferred to MACV-SOG in July of 1964. MACV-SOG was tasked with covert missions against Northern Vietnam. The unit was supported by an increase of 130 SIGINT personnel to support their monitoring and infiltration operations [source]. This led to a significant increase in the number of operations being undertaken by MACV-SOG: evidence suggests that offensive operations were being launched almost daily.

On the night of the 30th of July 1964, MACV-SOG launched a midnight naval assault on the Vietnamese islands of Hon Me and Hon Nieu. In the early hours of the 31st of July, MACV-SOG personnel began their assault on the Vietnamese islands.

However, attacks on both of the islands were unsuccessful. On Hon Me, South Vietnamese operatives opened fire from shore, forcing US retreat. This rendered their plan to plant explosive charges completely unsuccessful. On Hon Neiu, the result was similar: US forces retreated within 45 minutes of beginning their offensive [source].

The Gulf of Tonkin Incident

As a result of Operation 34A, North Vietnamese forces became increasingly suspicious of US naval presence, building up their own presence around the islands of Hon Me and Hon Nieu. Their increased SIGINT capabilities meant increased monitoring of US vessels. Whilst US naval forces did indeed intercept Vietnamese messages indicating that they were imminently launching offensives on US vessels, these went largely ignored [source]. As a result, on August 2nd, the USS Maddox came under attack by 3 Vietnamese torpedo boats.

The Gulf of Tonkin Incident directly led to the US’ increased involvement in the Vietnam War. US Congress passed the Gulf of Tonkin Resolution on August 7th of 1964. This resolution allowed President Johnson the power to ‘retaliate and to promote the maintenance of international peace and security in Southeast Asia’ [source]. This effectively gave the US government a legal basis to become further involved in the Vietnam War.

Whilst the US initially blamed North Vietnam for the unforeseen bombardments, later declassified documentation showed the MACV-SOG’s involvement in clandestine monitoring and attack operations prior to the Incident, highlighting the US’ culpability.

A Vietnamese Thanksgiving

On Thanksgiving day of 1968, MACV-SOG was tasked with arguably its most challenging mission yet. Army Intelligence had lost the position of multiple North Vietnamese army divisions. This meant that there were 30,000 Northern Vietnamese troops unaccounted for.

MACV-SOG were tasked with locating the enemy troops to update US Army Intelligence. This was assigned to one specific MACV-SOG team who were best placed in the area the troops were last located: ST Idaho. ST Idaho was comprised of only six men: four indigenous troops, and two Green Berets [source]. They were led by John Stryker Meyer, as pictured below.

John Stryker Meyer (Left) and Lynne Black Jr. (Right
(Img; John Stryker Meyer (Left) and Lynne Black Jr. (Right); via Sandboxx)

6 Versus 30,000

The State Department had strict rules for engagement in Cambodia, meaning that air support was not an option whilst they were on this mission. Meyer and ST Idaho were completely on their own.

Meyer and his team began their search for the missing troops. Soon, they located an enemy camp that appeared to be empty. The team raided the camp for any clues about enemy whereabouts. However, after a short amount of time, one of the team’s indigenous personnel was alerted to an enemy approach. ST Idaho quickly began exfiltration, and just in time, hundreds of North Vietnamese soldiers began to flood the camp, opening fire at the MACV-SOG unit [source].

ST Idaho quickly made their way to their landing zone, lobbing grenades and firing at the North Vietnamese forces as they moved. US gunships manned by Green Hornets airlifted ST Idaho away from the landing zone, with the team barely escaping with their lives.

Other Operations

Other common missions included counterintelligence through bugging of enemy communication systems, infiltrating enemy strongholds, and any other assignments that would allow US forces to gain more information on the number and location of Vietnamese troops throughout the continent [source]. As the group was comprised of highly trained troops from well-trained US forces, the group regularly undertook specialised operations such as high-altitude parachute jumps behind enemy lines and naval missions [source]. The MACV-SOG was also responsible for with the recovery of wounded soldiers.

Disbandment and Recognition

The MACV-SOG, whist instrumental to the war effort, has one of the highest casualty rates of any US force. The force’s casualty rate exceeded 100% – every single SOG officer was wounded at least once, and over half of the force was killed in action [source].

MACV-SOG was ultimately deactivated on the 29th of March 1973 [source]. Subsequently, this became the US National Vietnam War Veterans Day from 2017. Owing to the secret nature of the work, much of the information surrounding the covert force is only just becoming available within the public domain.

In 2001, MACV-SOG received the Presidential Unit Citation for its efforts during the 60s and 70s [source].


The inconspicuously named “Military Assistance Command” was a large clandestine intelligence operating throughout Asia. Ultimately, the group’s operations were instrumental to the success of the US war effort in Vietnam.

This piece was contributed to by Wes Martin

Abbi Clark
Abbi Clark
Abbi is a Grey Dynamics's Intel Manager and a graduate in Chinese Studies from the University of Nottingham with an MA in Intelligence & Security Studies at Brunel University London.


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