Viet Cong soldier stands beneath carrying his AK-47 rifle. He was participating in the exchange of POWs by the Four Power Joint Military Commission. Photo by SSgt. Herman Kokojan – Defense Visual Information Center.
During the Vietnam War, the United States employed various forms of unconventional warfare to undermine enemy operations. Among these clandestine tactics, one of the most insidious was Project Eldest Son, a psychological warfare operation designed to erode trust among North Vietnamese forces by sabotaging their ammunition supply.
This initiative, also known by the alternate code names Italian Green and Pole Bean, relied on psychological operations (PSYOPS) to instill doubt and fear among communist soldiers, highlighting the strategic depth of unconventional warfare. While some operations are referred to as “Operation [Name],” this particular effort was designated as a project rather than an operation.
Origins and Execution
Project Eldest Son was conceived and executed by the U.S. Army Studies and Observations Group (SOG), one of the most secretive special operations units of the war. The goal was simple yet highly deceptive: modify enemy ammunition so that it would fail catastrophically when used. This involved tampering with standard-issue munitions used by North Vietnamese forces, ensuring that some of them would explode when fired.
The United Kingdom had previously utilized small arms ammunition sabotage during key military engagements, such as the Second Matabele War (1896–1897) and the Waziristan campaign (1936–1939). These efforts proved effective, largely because the opposing tribal forces relied on recovered ammunition rather than a steady supply of newly manufactured rounds. During his tenure as commander of the Studies and Observations Group (SOG) from 1966 to 1968, Colonel John K. Singlaub, who later became a Major General, was a seasoned operative from the Office of Strategic Services (OSS) during World War II and advocated for similar tactics.
SOG’s operatives devised a method to sabotage 7.62×39mm cartridges used in AK-47 rifles, 12.7mm heavy machine gun rounds, and 82mm mortar shells. These types of ammunition were widely relied upon by communist forces, making them perfect targets for infiltration.
Officially established in 1964, SOG functioned under direct command from the Joint Chiefs of Staff, carrying out highly classified missions in Vietnam, Laos, Cambodia, and North Vietnam. The unit was composed of elite personnel drawn from the U.S. Army Special Forces (Green Berets), Navy SEALs, Air Force Air Commandos, and CIA operatives. Their primary objectives included:
- Reconnaissance and intelligence gathering deep behind enemy lines.
- Sabotage and psychological warfare aimed at disrupting enemy operations.
- Unconventional warfare tactics, including deception and misinformation campaigns.
Rather than placing large caches of sabotaged ammunition in enemy-controlled zones, SOG operatives carefully mixed small quantities of faulty rounds into legitimate stockpiles. This ensured that failures appeared random, increasing paranoia among communist troops. Since the Viet Cong relied heavily on captured and salvaged ammunition, they were particularly vulnerable to this tactic.
Psychological Warfare and Strategic Impact
Creating Distrust and Paranoia
The effectiveness of Project Eldest Son lay not in its physical destruction but in the psychological disruption it created. The goal was never to kill large numbers of enemy combatants; instead, it was to destroy their trust in their own weapons. If soldiers began to fear that their rifles or mortars might betray them in battle, hesitation and uncertainty would naturally follow.
The ultimate psychological impact meant reduced battlefield efficiency—instead of confidently engaging in combat, soldiers would second-guess their equipment. Hesitation and fear could be lethal in war, creating an advantage for American forces.
To amplify this effect, SOG operatives strategically planted these sabotaged rounds in captured enemy ammunition depots, along supply routes, and among battlefield pickups. By infiltrating established supply chains rather than creating new ones, failures seemed more organic, further increasing paranoia. Since the Viet Cong relied heavily on captured and salvaged ammunition, they were particularly vulnerable to this tactic.
Exploiting Communist Command Structure
The chain of mistrust went beyond individual soldiers. Communist forces relied heavily on Chinese and Soviet-provided munitions, meaning that unexpected weapon failures forced commanders to reassess their supply chains. They needed to inspect caches, question sources, and determine whether their allies were distributing defective rounds. This created internal friction—if soldiers believed their allies were supplying faulty ammunition, it could damage the relationship between North Vietnam and its supporters.
Countering Soviet and Chinese Influence
One of the unintended consequences of Project Eldest Son was strain between North Vietnam and its Communist allies. If soldiers began to suspect that their failing weapons originated from Chinese or Soviet factories, questions would arise about the reliability of foreign aid. While it is unclear how much this affected long-term political dynamics, it was a subtle way to undermine faith in external military support.
Limitations and End of the Operation
Despite its psychological potency, Project Eldest Son had inherent limitations. Like all covert sabotage operations, its effectiveness was dependent on secrecy. Once North Vietnamese intelligence became aware of the program, its impact diminished.
North Vietnamese Countermeasures
Once the operation was exposed, counter-PSYOPS were put into place by Communist forces. They adapted by:
- Inspecting ammunition sources carefully.
- Implementing test procedures to ensure rounds were not sabotaged before distribution.
- Propagating messages to reassure troops and neutralize fear.
The North Vietnamese also released internal directives warning soldiers about the sabotage, urging caution when handling captured American munitions. These efforts neutralized much of the paranoia, reducing the disruptive effect of Project Eldest Son.
Additionally, U.S. officials feared international backlash if the operation were widely publicized. If adversaries realized that America had deliberately sabotaged ammunition, accusations of war crimes could arise. Given the potential diplomatic risks, the U.S. government discontinued the operation before its exposure created greater consequences.
Legacy and Lessons in Psychological Warfare
Project Eldest Son remains an important case study in psychological warfare, demonstrating how perception manipulation can alter battlefield outcomes. Rather than using brute force, subtle psychological tactics can weaken enemy confidence, creating strategic advantages that go beyond direct combat.
Key Takeaways
- Psychological warfare is often more effective than direct combat. The fear of danger can be just as powerful as actual battlefield losses.
- Sabotaging enemy resources can create internal instability. If a fighting force loses trust in its equipment, its overall effectiveness declines.
- Covert operations must remain undiscovered. Once compromised, psychological tactics lose their impact.
Final Thoughts
Project Eldest Son serves as a testament to the creativity of military strategy, particularly in unconventional warfare. It underscores the reality that war is fought not just with weapons, but with perception, misinformation, and psychological influence. Though short-lived, the operation provided valuable insights that modern military strategists continue to refine and implement in contemporary conflicts.
