The Military Assistance Command Vietnam, Studies and Observations Group (MACV-SOG) was an elite US special operations unit formed in January 1964. Its charter was to conduct clandestine operations in Southeast Asia–particularly cross-border operations in Laos, Cambodia, and North Vietnam–assuming many of the clandestine missions previously conducted by the CIA. Sometimes simply referred to as ‘SOG’, the inconspicuously named unit was responsible for all manner of reconnaissance, special operations, and psyops in the theatre during the Vietnam War.
The group was comprised primarily of Army Green Berets, with smaller numbers of Navy SEALs, Marine Force Recons, Air Force Air Commandos, and even a few Australian Special Air Services Regimen (SASR), a special forces unit of Australia’s army. The existence of the force, and its activities, were highly compartmented at the top secret level and operatives were held to secrecy agreements that spanned 20 years. As a result, families of MACV-SOG members were not informed of the details of the loss of those who were killed in action.
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1 Operational Structure
1.1 Command and Control
MACV-SOG fell under the control of the US Military Assistance Command Vietnam, the US military command overseeing all US military activities in South Vietnam. The Military Assistance Command was a subsidiary of the US Pacific Command. The first commander of MACV-SOG was Colonel Clyde Russell.
MACV-SOG was headquartered in Saigon (now Ho Chi Minh City), with its subordinate units having multiple operational bases throughout Vietnam and surrounding territories.
However, MACV-SOG had direct instruction from the Pentagon on specific missions. Specifically, from the Special Assistant for Counterinsurgency and Special Activities (SACSA) and his staff at the Pentagon.
1.2 Subsidiary Units
In the early years, 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.
1.2.1 SOG-31 Maritime Studies Branch
The Maritime Studies Branch (Also known as SOG-31 or OP-31), codenamed “Plowman” was primarily concerned with maritime operations. Within SOG-31 there was another branch known as the Maritime Studies Group, alternatively called SOG-37 or OP-37.
Maritime Studies Group
The Maritime Studies Group was responsible for covert maritime operations that were conducted by the Vietnamese Coastal Security Service (CSS). Its cover name was “Naval Advisory Department.” Within this group, extensive maritime operations training was carried out in Da Nang and through conducting operations against selected targets in South Vietnam.
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1.2.2 SOG-32 Airborne Studies Branch
OPS-34, also known as the Airborne Studies Branch, was responsible for the infiltration into North Vietnam via air. The operations under this branch were transferred to the Ground Studies Branch (SOG-34/OPS-34), which became a staff section. SOG-36/OP-36 was created and titled the Airborne Studies Group.
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1.2.3 SOG-33 PSYOP Studies Branch
The PSYOP Studies Branch (Also Known as SOG-33 or OP-33), codenamed “Humidor”, was composed of several different sections and they were primarily concerned with conducting covert psychological operations directed at North Vietnamese forces.
The sections within SOG-33 were:
- Section A – Research and development
- Section B – Radio
- Section C – Special Projects
- Section D – Printed Media, Forgeries, Blackmail (the military oversaw print media, CIA oversaw forgeries and blackmail)
Operations conducted by the PSYOP Studies Branch (SOG-33) include:
- Contamination of enemy munitions
- Mailing of fake letters, gifts, and leaflets
- Preparation of forged currency for use in Laos
- Manufacture of boobytraps
- Sacred Sword of the Patriots League (More below – See operations section)
SOG-33 was redesignated SOG-39, Psychological Studies Group, in 1968.
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1.2.4 SOG-35 Ground Studies Branch
The Ground Studies Branch (aka SOG-35 and OPS-35) was responsible for cross-border operations. It was comprised of three different elements:
Special Operations Augmentation Command and Control Central (SOA-CCC)
SOA-CCC formed in November 1967 and left Vietnam in March 1971. Stationed in Kontum, it was responsible for classified unconventional warfare operations in the tri-border regions, including:
- Laos
- Cambodia
- Vietnam
CCC contained several different teams, including:
- 30 Spike Reconnaissance Teams (RTs)
- Hatchet Forces
- Four Search, Locate, and Annihilate Teams (SLAM)
- SLAM Company A
- SLAM Company B
- SLAM Company C
- SLAM Company D
The RT forces were originally named after US States (such as Arizona, New Mexico, etc.) but later adopted the names of Asian poisonous snakes once all the state names had been exhausted. (More Information Below – Hatchet and Spikes section).
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Special Operations Augmentation Command and Control North (SOA-CCN)
SOA-CCN was formed in November 1967 and left Vietnam in March 1971. Assigned to conduct classified special unconventional warfare in the following countries:
- Laos
- North Vietnam
It was composed of the following:
- Spike Reconnaissance Teams (RTs)
- Hatchet Forces
- SLAM Companies
CCN Operations were initiated as early as 1 February 1964 under Operation Plan 34A. Operations in Laos began in September 1965 under Operation ‘Shining Brass,’ renamed ‘Prairie Fire’ in 1968. In 1971, the operations conducted in Laos were given the codename ‘Phu Dung’.
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Special Operations Augmentation Command and Control South (SOACCS)
SOACCS was formed in November 1967 and departed Vietnam in March 1971. Located in Ban Me Thuot, it oversaw cross-border missions in Cambodia.
It was assigned to conduct classified special unconventional warfare in the following countries:
- Vietcong-dominated regions of South Vietnam
- Cambodia
It was composed of the following:
- Spike Reconnaissance Teams (RTs)
- Hatchet Forces
- Four SLAM Companies
Cross-border operations were conducted by SOACCS in northeastern Cambodia since May 1967 under the codename, ‘Project Daniel Boone’. This later became known as ‘Salem House.’ In 1971, the operation’s name was changed to ‘Thot Not.’
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FOB (Forward Operating Bases)
Prior to 1968, CCN, CCC and CCS were called FOBs (Forward Operating Bases). There were four FOBs:
- FOB1 – Later became CCN
- FOB2 & FOB3 – Combined to form CCC
- FOB4 – Later became CCS
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2 Equipment
The equipment carried by MACV-SOG was significantly different from that of the mainstream army forces, owing to the unconventional warfare they undertook. The unit primarily carried variants of the XM-177, an experimental carbine variant of the M16 rifle used by conventional forces.
[Note: the weapon was referred to as the CAR-15]
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2.1 XM-177
In many ways, the XM-177 was the precursor to the M4. Colt would eventually take many of the features of the XM-177 and implement them into their iterative carbine designs. There were two official XM-117s, the XM-177 E1 and XM-177 E2. The nomenclature of “XM” denotes that it is an experimental design that is yet to be formally adopted. The E denotes an “enhancement.”
2.1.1 Stats
- Manufacturer: Colt Defense
- Barrel Length: 25.4 cm (10 in) (E1) / 29.2 cm (11.5 in) (E2)
- Overall Length: 72 cm (28.3 in) (E1, stock retracted) / 76 cm (29.8 in) (E2, stock retracted)
- Operating System: direct gas impingement, box magazine fed
- Calibre: 5.56x45mm NATO
- Weight: ~ 2.43 kg (5.35 lb)
- Max effective range: 400
2.1.2 The Barrel
The XM-177 E-1 featured a 25.4 cm (10 in) barrel. This is half the length of the M16 from which the XM-177 is derived. However, the XM-177 had an additional muzzle device known as a moderator. The moderator added 10.6 cm (4.2 in) to the barrel, reducing much of the compactness of the XM-177. The exact purpose of the moderator is widely debated. Due to having internal baffles like a suppressor, some claimed that it reduced the decibels enough to make it sound like an AK-47 when firing.
However, the most likely reason for the moderator was to improve reliability. At this time Colt had been struggling to get their short barrel carbines to cycle reliably. This is primarily due to the lack of dwell time, and the distance between the gas port inside the barrel and the muzzle. On a 25.4 cm (10 in) barrel the gas port and the muzzle are very close to each other, reducing the amount of time for the gas behind the bullet to travel through the gas port and cycle the action before the bullet exits and the pressure drops.
The baffles inside the moderate slow the gas down, which does reduce the decibel levels when firing. However, they also significantly increase the back pressure even after the bullet exits the muzzle. As a result, there is more gas pressure inside the system, allowing it to run more reliably.
2.1.3 The Stock
The other major change between the XM-177 and the M16 was the stock. Earlier Colt prototypes tried to convert the fixed stock into a collapsible one. However, they were fragile and as a result, Colt went back to the drawing board.
The XM-177 featured the basic collapsing stock design that has carried onto the M4 and all its derivatives. The XM-177’s stock had two positions: all the way extended and all the way collapsed. The subsequent carbine designs would improve upon this by increasing the positions from two to four and then to six, allowing the user to adjust the stock for their comfort based on their size and body armour.
The sliding stock itself was originally made of aluminium with a protective coating. Subsequent iterations copied the basic design but swapped the aluminium with plastic. This provided both a lighter rifle and reduced production costs.
2.1.4 The Second Enhancement
The next iteration of the XM-177 was the E2. The E2 retained the bulk of the features from the E1, with only one major change. The barrel length was increased to 29.2 cm (11.5 in). This had a minor reductive effect on the flash and sound of the carbine when fired. It also increased the dwell time and therefore the reliability.
The E2 retained the moderator but included a grenade ring mounted behind it. The increased length of the E2 combined with the grenade ring allowed the user to mount an under-barrel grenade launcher.
2.1.5 Beyond
As previously stated, the XM-177 was the precursor to many modern military carbines. Its influence can be seen in Colt’s various iterative carbines and eventually the M4. Recognizing that the moderator increased the overall length of the barrel to 36 cm (14.2 in), Colt standardised the barrel length to 36.8 cm (14.5 in).
The extended barrel provided the user with a more effective weapon in the same-sized package. By replacing the 10.6 cm (4.2 in) of the moderator with more barrel, they were able to increase reliability and lethality. The longer barrel allows the bullet to reach higher velocities which gives it better terminal ballistics as a result.
The military would eventually revisit the 25.4 cm (10 in) barrel design with the Mk 18.
However, this time, the Navy’s Crane Division was able to increase the gas port diameter and the length to 26.2 cm (10.3 in). As a result, much of the reliability issues were solved and the Mk 18 would see wide use by US special operations forces.
2.2 AK Variants
Members of MACV-SOG would often utilise enemies’ weapons for various reasons. Enemy forces carried a multitude of weapons, including old bolt action rifles. However, if SOG riflemen were going to use an enemy weapon, it was likely an AK variant. During the Vietnam War, this could mean anything from a Soviet-produced AKM to a Chinese Type 56. The Type 56 is an amalgamation of various Soviet weapon designs. The receiver is milled like an original AK-47 and the stock/pistol grip mount accordingly. However, the handguard is similar to that of an AKM and it features a vented gas tube. Additionally, it has an integrated folding bayonet like a post-WW2 SKS.
2.2.1 Stats
- Manufacturer: Multiple Manufacturers
- Barrel Length: 41.4 cm (16.3 in)
- Overall Length: 88.2 cm (34.7 in)
- Operating System: Long stroke gas piston, box magazine fed
- Calibre: 7.62x39mm
- Weight: ~ 3.7 kg (8.16 lb)
- Max effective range: 400 m
2.3 RPD
The RPD is another Soviet design favoured by MACV-SOG operators. The closest parallel the US military had at the time was the M60 machine gun. However, the M60 was bulky, and heavy, and fired a heavy 7.62x51mm NATO cartridge. The M60 was not suitable for SOG’s purposes. However, they still needed a support weapon, so a few operators began modifying captured enemy RPDs.
The RPD is a light, belt-fed machine gun, chambered in 7.62x39mm. It was manufactured in the Soviet Union, China, and many other countries.
Typically SOG operators would cut down their rifle’s barrel, which meant losing the weapon’s front sight. However, the machine gunners would compensate by point firing or hip firing in the close quarters of the thick Vietnamese jungles.
2.3.1 Stats (non-cut down version)
- Manufacturer: Multiple Manufacturers
- Barrel Length: 52 cm (20.5 in)
- Overall Length: 103.7 cm (40.8 in)
- Operating System: Long stroke gas piston, belt-fed
- Calibre: 7.62x39mm
- Weight: ~7.4 kg (16.31 lb)
- Max effective range: ~600m
2.4 M79 Grenade Launcher
The M79 was one of the first standalone grenade launchers. The M79 fires self-contained 40mm grenades, as opposed to the rifle grenades it replaced. (Rifle grenades required a special muzzle device, high-pressure blank cartridges, and a gas system shut off to properly fire.)
There were huge margins for error if the soldier forgot a step, especially if they forgot to switch live ammo for the blanks. The development of the M79 allowed the Grenadier to provide much greater firepower at a faster rate. The primary downside was that the grenadier no longer had a fighting rifle.
Consequently, they were reliant on their pistol and/or fellow riflemen to engage close targets. Oftentimes, SOG operators would cut off the stock and the barrel of the M79 to have a lighter and more compact package.
2.4.1 Stats
- Manufacturer: Springfield Armory and others.
- Barrel Length: 36.83 cm (14.5 in)
- Overall Length: 73 cm (28.8 in)
- Operating System: Single shot, break action
- Calibre: 40mm Shells
- Weight: ~ 2.7 kg (6 lb)
- Max effective range: 400 m
2.5 Explosives
SOG operators loved fragmentation grenades. They work wonders to clear out enemy fighting positions such as bunkers and to break contact. A typical SOG loadout included about 10-12 grenades. Additionally, SOG operators would sometimes pack Claymore mines as initiators for ambushes.
Operators would lie in wait for the enemy to walk into their field of fire, and then they would detonate the mine to kill as many enemies as possible and stun those who weren’t killed. They would then open fire with their weapons to finish off the ambush
Explosives used by SOG:
- V-22 Mini-grenades
- M-26 Fragmentation grenades
- M-33 Fragmentation grenades
- Claymore Mines
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2.6 Deniability
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 provide a semblance of deniability if the soldiers, and the US by extension, were caught operating in areas they weren’t supposed to be in.
This is also a contributing reason for MACV-SOG operators to also use captured AKs and RPDs. Often the point man would carry an AK or RPD due to the distinctive sound of the 7.62x39mm round firing. The weapon’s report is easily distinguishable from that of an M16/XM-177.
Having the point man utilise an enemy’s weapon allowed him to fire a short burst at a lone combatant, if needed, without compromising the unit’s presence. Enemies in the area could not readily identify the shooter as American by sound.
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2.7 Other Weapons
2.7.1 Highly Modified M1 Carbine
The M1 Carbine was first adopted by the US during WW2. It saw service well into the Vietnam War, primarily by rear echelon and special operations troops. Much like today’s special operations forces, soldiers in MACV-SOG would modify their gear to suit their needs. The image above shows an M1 Carbine that has had its stock cut off, converted from .30 Carbine to 9x19mm. It also was modified with the addition of a magnified optic, a forward grip, and a suppressor.
2.7.2 Suppressed Beretta 951
Today 9x19mm handguns are used by almost every military and police force in the Western Hemisphere, but in the late 60s and early 70s, they were pretty rare. This was the beginning of the Wonder Nine era, a colloquialism for the sudden surge of increased capacity of 9mm handguns flooding the market. Before this soldiers and police were limited to 6-round revolvers and 7-8 round autoloading pistols.
However, the Beretta 951 was the precursor to the well-known Beretta 92 or M9. The one pictured above is outfitted with a suppressor, likely used as a sentry stopper, a quiet weapon used to take out an individual enemy without alerting surrounding forces. MACV-SOG operators also used the Browning Hi-Power, another Wonder Nine designed by the same man who designed the M1911.
2.7.3 Welrod
The Welrod was designed from the ground up to be a sentry stopper by the British SOE during WW2. It lacks automatic reciprocating parts and has ports drilled into the barrel and a large suppressor.
The lack of reciprocating parts means that when it is fired, nothing that can produce sound moves. The holes drilled into the barrel reduce the pressure behind the 9mm bullet, meaning it never reaches supersonic speeds; there is no supersonic boom when it is fired.
Lastly, the suppressor slows down the gases produced from firing the bullet. So, when fired, the loudest noise produced by the Welrod comes from the bullet impacting its target.
2.7.4 Sten Gun and Swedish K
World War 2 saw a rise in the use of submachine guns by almost every country on the planet. They are lightweight and compact, but not very good outside of close-quarters combat.
However, the dense foliage of Vietnamese jungles saw the occasional use of submachine guns due to the relatively short lines of sight. It’s worth noting that neither of these weapons is American-made. This is not because the US lacked any submachine guns in war stock. Rather, it was an additional factor of deniability for MACV-SOG.
2.7.5 Suppressed High Standard
The High Standard is another example of a sentry stopper. The pistol was chambered in a .22 long rifle (.22 LR), a calibre with a misnomer of a name. The .22 LR is one of the smallest common commercial calibres on the market and is very common in marksmanship competitions.
The High Standard pistol pictured is a competition target pistol modified to have a suppressor. Due to the small size of the .22, it is very easy to suppress and subsonic loads are coincidentally common.
The .22 LR round is fast enough to break the sound barrier, but it will usually slip back below the sound barrier before it hits its target. Slipping between super and subsonic has a detrimental effect on accuracy.
As a result, most competition loads of .22 LR use a heavier bullet so that it never breaks the sound barrier in the first place. This provided competition shooters with a more accurate .22 LR cartridge and MACV-SOG with an easily procured subsonic cartridge to use as a sentry stopper.
2.7.6 The Gyrojet
MACV-SOG also dabbled in experimental weaponry. The “Gyrojet” pistol was a firearm that fired miniature rockets, dubbed “Microjets” that gyroscopically kept the bullet in balance. It was surprisingly light and transportable and in turn, was known to be used by the unit. [source] They were incredibly inaccurate and unreliable, explaining why the concept has never been revisited in the past 80 years.
2.8 Kit
Soldiers in MACV-SOG often utilised highly modified kits to suit the needs of their irregular missions. During the Vietnam War, standard U.S. soldiers had limited kit options, and the aftermarket for gear was far smaller than the one we see today. As a result, soldiers often got creative. SOG operators typically carried as much ammunition as possible, sometimes up to 34, 20-round magazines. In comparison, a standard fighting load carried by infantrymen today is seven, 30-round magazines.
One widely used technique to carry the massive loadout was to use canteen pouches to hold additional magazines. The pouches were capable of holding five 20-round magazines with one at the ready in the pouch’s opening. Additionally, MACV-SOG would use kits from WW2, such as magazine belts for Browning Automatic Rifle (BAR) gunners.
Towards the end of the war, 30-round magazines for the M16/XM-177 became more prevalent. Enemy forces often used Chinese-type 56 chest rigs to hold their 30-round AK magazines.
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2.8.1 Additional Equipment
In addition to the full combat loadout of ammunition and grenades that SOG operators carried, they also carried many other mission essential items, such as:
- Pens
- Notebooks
- Pen flares
- A plastic spoon
- Signal mirror
- Maps
- Morphine syrettes
- URC-10 emergency radio
- PRC-25 radio
- Luminescent watch
- Compass
- Gloves
- Canteens (number dependent on water in the operational area)
- Fixed blade knife
- Swiss Army Knife
- Machete
- Smoke grenades
- Bandages
- Strobe lights
- Rappelling D-ring
- White-phosphorus grenade
- Water purification tablets
- M-17 gas mask
- Dehydrated rations
- Bug repellent
- 3.6m (12 ft) line of rope
- Rain jacket
- Toilet Paper
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2.8.2 McGuire Rig and STABO Harness
Fighting in the thick canopy jungles meant that SOG operators had to get creative with their exfiltration methods. Oftentimes, operators needed a quick extraction but there was no opening in the trees big enough or flat enough to land a helicopter. As a result, they began to use McGuire rigs. Named after Sergeant Major Charles McGuire, the McGuire rig was essentially a long length of rope with a loop at the bottom big enough for one man to sit in.
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The McGuire rig worked well enough, however it had serious flaws. It was extremely uncomfortable to sit in during long flights. Additionally, operators would sometimes fall out of the rig if they were a casualty or if the helicopter encountered severe weather.
As a result, SOG created the Stabilized Body (STABO) extraction harness. The STABO rig closely resembled a parachute harness, however, its primary purpose was to secure the user directly to the helicopter’s extraction line. Operators began to hang their kit directly off the STABO harness rather than the standard issue ALICE load-bearing equipment.
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2.9 Uniforms
MACV-SOG operators are best known for their Tiger Stripe camouflage fatigues. However, according to one of the most well-known MACV-SOG vets, John Stryker Myer, they were rarely used.
The tiger stripe camo uniforms were more of a status symbol when not on missions, distinguishing the elite operators while on an operating base. However, while on missions MACV-SOG operators would use standard-issue green fatigues because they dried quicker in the hot and humid jungle.
Despite not being particularly effective, the camo pattern has persisted in various forms. Central Intelligence Agency Global Response Staff and paramilitary operations officers have worn a desert variant while operating in Iraq and Afghanistan.
Additionally, members of the 5th Special Forces Group have used the old jungle tiger stripe during training exercises as a homage to their Vietnam-era Green Beret/MACV-SOG heritage.
3 Tactics, Techniques, and Procedures
MACV-SOG had a multitude of mission sets that they conducted in the theatre, ranging from reconnaissance to psychological operations. Operators often worked with indigenous partner forces to complete these missions. Together, these teams of American, Vietnamese, Cambodian, Hmong, and Montagnard soldiers essentially rewrote the doctrine for reconnaissance missions.
3.1 Isolation
MACV-SOG operators were so effective, the Vietnamese established tracking teams to hunt them in the jungle. As a countermeasure, before long-range reconnaissance patrols (LRRPs), MACV-SOG operators entered a period of isolation. They consumed only local food, drank local beverages, and smoked Vietnamese cigarettes to mask their foreign odour while patrolling in the jungle. A professional Vietnamese tracker could tell the difference in the smell of bodily waste of someone eating an American diet vs a local diet.
3.2 Partner Forces
MACV-SOG’s primary stomping ground during the war was the Ho Chi Minh Trail. While the name might conjure images of a short single path through the jungle, in reality, it was much more complex.
The “trail” consisted of more than 3,000 km (1864 mi) of roads, foot trails and tunnels. It stretched across Vietnam’s eastern border into Laos and Cambodia. During the war the US wasn’t allowed to officially acknowledge any cross-border operations; they could only operate within Vietnam. However, a large part of the trail is outside of the country.
As a result, the Vietcong and North Vietnamese Army used the trail as a logistical pipeline for supplies, presenting a rich target for MACV-SOG and their partner forces.
MACV-SOG stood up primarily to act as a covert force that could conduct deniable missions in Laos and Cambodia. The operatives themselves were recruited primarily from the Army Special Forces, primarily due to the unit’s mission of training and fighting alongside indigenous partner forces.
MACV-SOG recruited partner forces who were ideologically aligned with the US mission in Vietnam. The local warriors spoke the local dialects, knew the terrain, and aided in deniability if a mission was compromised. Together, these teams became extremely close.
3.2.1 Yard Bracelets
Montagnard forces sometimes referred to colloquially as “Yards,” often bestowed upon their American brethren camaraderie bracelets. They were made of brass casings that were hammered out, polished, and etched with designs. Being given a bracelet was considered a great honour and signified a lifelong friendship and commitment between the giver and the recipient.
In turn, Americans who developed close ties with their Montagnard counterparts often sponsored them to come to the US after America withdrew from Vietnam. As a result, there are Montagnard enclaves in unusual places across the US. For instance, in the state of Minnesota, the largest Asian group today is the Hmong.
3.3 Hatchets and Spikes
The two primary missions of these teams were direct action and reconnaissance.
3.3.1 Hatchet Teams
Hatchet teams were MACV-SOG’s primary raid force. They would conduct direct action missions and ambushes along the Ho Chi Minh Trail. Additionally, they could act as a quick reaction force for reconnaissance teams that were compromised.
A typical hatchet team was composed of five Americans and 30 indigenous soldiers. For larger operations, multiple hatchet teams would be combined to make a havoc team to target enemy strongholds and conduct larger operations.
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3.3.2 Spike Teams
Reconnaissance teams were known as spike teams. They would typically name themselves after US states, with the typical name being something like the ST Missouri. However, the use of the term spike teams fell out of favour and they began calling themselves recon teams or RTs. They kept the tradition of naming the RTs after states with the occasional odd name like RT Bushmaster.
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3.3.3 SLAM Companies
In addition to the Hatchet Forces, there were also the “SLAM” companies, standing for Search, Locate, Annihilate, Monitor/Mission, which were full-sized MACV-SOG companies with a few dozen Americans in leadership roles and a few hundred indigenous mercenaries recruited by MACV-SOG.
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3.4 The Phoenix Program
Intelligence collection units affiliated with the Military Assistance Command Vietnam (MACV) participated in an initiative referred to as the ‘Phoenix Program.’ This program, directed by the CIA, sought to undermine the operational framework of the Viet Cong through a combination of targeted killings, intelligence acquisition, and psychological operations. The strategies employed were influenced by methodologies derived from Nazi-era experiments.
In 1967, MACV unified all military and civilian pacification initiatives under a single organisation, the Civil Operations and Revolutionary Development Support (CORDS). The CIA and MACV played significant roles in CORDS, which operated in conjunction with the government of Saigon.
The Phoenix Program, while ostensibly managed and overseen by the Saigon government, was primarily funded and orchestrated by the CIA. This initiative expanded upon the efforts of a CIA-established network comprising more than 100 provincial and district intelligence operation committees in South Vietnam, which were responsible for gathering and distributing intelligence regarding the Vietcong Infrastructure (VCI) to local police forces and paramilitary groups.
The MACV command claimed that the Phoenix Program, in conjunction with the US military’s actions during the Tet Offensive and various rural security and militia initiatives, had resulted in the elimination of over 80,000 VCI members through means such as defection, detention, or death.
4 Notable Operations
Although much of the details of MACV-SOG operations remain classified, it 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. It is believed that OP-35 had a force of up to 2,500 US personnel and 8,000 indigenous troops , segmented into smaller teams as small as 10 men. These tended to include a mixture of US Green Berets, specialised in unconventional warfare, as well as local warfighters. These indigenous troops, colloquially known as “little people”, came from multiple regional countries such as China, Cambodia, and South Vietnam.
Indigenous people were key to MACV-SOG’s success. This is because they brought a wealth of background information on local geography, language, and culture.
4.1 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 the 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 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.
This led to a significant increase in the number of operations being undertaken by MACV-SOG,with some evidence suggesting that offensive operations were being launched almost daily.
On 30 July 1964, MACV-SOG launched a midnight naval assault on the Vietnamese islands of Hon Me and Hon Nieu. In the early hours of 31 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 the US to 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.
4.2 The Gulf of Tonkin Incident
As a result of Operation 34A, North Vietnamese forces became increasingly suspicious of the US naval build up around the islands of Hon Me and Hon Nieu. The US forces’ increased SIGINT capabilities meant increased monitoring of communications relevant to the 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.
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’s increased involvement in the Vietnam War. The US Congress passed the Gulf of Tonkin Resolution on 07 August 7 1964. This resolution empowered President Johnson to ‘retaliate and to promote the maintenance of international peace and security in Southeast Asia’. 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 MACV-SOG’s involvement in clandestine monitoring and attack operations prior to the Incident.
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4.3 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 was tasked with locating the enemy troops to update US Army Intelligence. This was assigned to one specific MACV-SOG team that was best placed in the area where the troops were last located: ST Idaho.
ST Idaho was comprised of only six men: four indigenous troops, and two Green Berets. They were led by John Stryker Meyer.
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(Img; John Stryker Meyer (Right) and Lynne Black Jr. (Left); via Sandboxx)
4.3.1 Six Versus 30,000
The State Department’s strict rules for engagement in Cambodia precluded air support for this mission. This meant that Meyer and his unit were without fire support.
Meyer and his team initiated their search for the missing troops. They located an enemy camp that appeared to be empty.
The team searched the camp for any intelligence regarding the enemy’s 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 entered the camp and began opening fire on the MACV-SOG unit.
ST Idaho quickly made their way to their landing zone, using grenades and firing at the North Vietnamese forces as they moved in order to provide fire support. US gunships manned by Green Hornets airlifted ST Idaho away from the landing zone. This allowed the team to evacuate from the area without suffering any casualties.
[Source]
4.4 Sacred Sword of the Patriots League
The Sacred Sword of the Patriots League (SSPL), known in Vietnamese as ‘Mặt trận gươm thiêng ái quốc’, was a covert operation initiated by the Central Intelligence Agency (CIA) and executed by MACV-SOG throughout the Vietnam War.
The SSPL was conceived and established in April 1963, and it ran until its completion in 1968. It served as the focal point for numerous psychological operations (PSYOP) aimed at North Vietnam, which was designated under the codename Humidor.
SSPL sought to persuade both the populace and, at times, the government of North Vietnam regarding the existence of an independent, non-communist society within its borders. The creation and dissemination of the “legend” surrounding the SSPL necessitated the U.S. Special Forces to build upon psychological warfare strategies that had been developed by the Office of Strategic Services (OSS) during World War II.
This operation encompassed elements of psychological warfare (PSYWAR) and psychological operations (PSYOP), which are currently referred to in the armed forces as military information support operations (MISO) and referred to as covert influence operations in civilian intelligence circles, including the CIA.
Certain historians contend that the SSPL successfully distracted North Vietnamese officials to a degree that could rationalise its expenditures and personnel allocation.
Nevertheless, the program is not recognized for any significant achievements and faced numerous challenges due to an absence of clear objectives. Ongoing conflicts between various military leaders in Vietnam and decision-makers in Washington hindered the program’s potential to evolve into a genuine counterrevolutionary entity within North Vietnam.
Ultimately, it was largely dismantled in 1968 after initial negotiations that led to the Paris Peace Accords of 1973.
4.5 Other Operations
Other common missions included counterintelligence through the 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. 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. The MACV-SOG was also responsible for the recovery of wounded soldiers.
5 Disbandment and Recognition
MACV-SOG, while 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 recon team member was wounded at least once, and over half of the force was killed in action.
MACV-SOG was deactivated on 29 March 1973. Subsequently, this became the US National Vietnam War Veterans Day in 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.
6 Summary
The inconspicuously named “Military Assistance Command Studies and Observation Group” was a large clandestine intelligence operation throughout Asia. Ultimately, the group’s operations were instrumental to the conduct of the US war effort in Vietnam.
7. MACV-SOG Reading List
7.1. SOG: The Secret Wars of America’s Commandos in Vietnam
- Author: John L. Plaster
- Publication Date: 1998 (paperback reissue 2020)
Why It’s Relevant
A foundational text on MACV-SOG’s history and purpose, Plaster—a former SOG recon sergeant—delivers firsthand details of the unit’s hush-hush cross-border missions in Laos, Cambodia, and North Vietnam. The book underscores SOG’s innovative tactics, the high casualty rates, and the extreme stealth required to operate “across the fence.”
7.2. Secret Commandos: Behind Enemy Lines with the Elite Warriors of SOG
- Author: John L. Plaster
- Publication Date: 2004
Why It’s Relevant
This follow-up from Plaster expands on SOG’s covert campaigns, profiling the remarkable heroism of Green Berets, SEALs, Air Commandos, and indigenous allies. Anecdotes illuminate SOG’s unique weaponry (XM-177 carbines, suppressed pistols), reliance on local Montagnards, and the behind-enemy-lines recon that made SOG a key intelligence asset.
7.3. Secret Green Beret Commandos in the Vietnam War: A Memorial History of MACV-SOG
- Author: Fred S. Lindsey
- Publication Date: 2012
Why It’s Relevant
Lindsey’s exhaustive memorial history pays tribute to SOG’s lesser-known missions, remembering both the extraordinary achievements and heavy losses. He compiles official records, personal stories, and declassified documents, revealing SOG’s cloak-and-dagger infiltration strategies and intelligence successes in supporting the broader war effort.
7.4. We Few: U.S. Special Forces in Vietnam
- Author: Nick Brokhausen
- Publication Date: 2007
Why It’s Relevant
Brokhausen, a former Green Beret with SOG, shares an up-close perspectiveon recon missions, the camaraderie of “indigenous” partner forces, and the unvarnished realities of cross-border raids. He offers vital details on SOG’s day-to-day hazards, kit customisation (mismatched uniforms, suppressed arms), and the crucial role of “sterilised” gear for deniability.
7.5. Across the Fence: The Secret War in Vietnam
- Author: John Stryker Meyer
- Publication Date: 2011 (revised editions available)
Why It’s Relevant
Meyer recounts his experiences as a recon team leader in MACV-SOG, detailing the shocking “30,000 vs. 6 men” moments and survival stories akin to the Thanksgiving day incident with “ST Idaho.” His personal narrative captures the deadly jungle environment, explains why SOG had some of the highest casualty rates, and honours the synergy with local Montagnards.
