Chemical Warfare during the Vietnam War

Riot Control Agents in Combat

D. Hank Ellison

• Publisher: Routledge
• Year: 2011
• Print ISBN: 9780415876452
• eBook ISBN: 9781136827198
• Topic: History
• Subtopic: Military & Maritime History
• Index: History

Chemical Warfare during the Vietnam War documents the use of antipersonnel chemical weapons throughout the Vietnam War, and explores their effectiveness under the wide variety of circumstances in which they were employed. The short, readable account follows the US program as it progressed from a focus on the humanitarian aspects of non-lethal weapons to their use as a means of augmenting and enhancing the lethality of traditional munitions. It also presents the efforts of the North Vietnamese to both counter US chemical operations and to develop a chemical capability of their own.

Chemical Warfare during the Vietnam War is a comprehensive and thoroughly fascinating examination of riot-control agents during the Vietnam War.

1

INTRODUCTION

Since the end of the war, the Vietnam-era chemical warfare program has been in and out of the news. Initially, concern focused on the potential long-term environmental damage from spraying herbicides on large sections of virgin jungle. It soon shifted to the toxic legacy left behind by dioxin, a minor but potent impurity in one of the herbicides. Because the principal ingredients in Agent Orange – a mixture of the butyl esters of 2,4-D and 2,4,5-T – were commercially available and considered non-toxic, there was little effort to prevent or even limit exposure during the war. As the world began to comprehend the extent of the damage, the impact to soldiers, civilians and now the next generation of Vietnamese children has been the topic of numerous medical studies, litigations and books. Dioxin’s notoriety has in turn raised public awareness of military defoliant operations during the war.

There was another facet of the chemical program that remains unconnected to any toxic legacy and has largely been overlooked by the general public. Riot-control agents were used routinely during combat operations for a variety of tactical reasons and the lessons learned from these operations are still having an impact on US Military planning and policy today. An examination of this aspect of the program can provide insight into the development of current US military doctrine and the drive to make these weapons available to soldiers. As recently as the invasions of Afghanistan and Iraq, the Pentagon pushed for authorization to use non-lethal chemicals. Secretary of Defense Donald Rumsfeld told Congress on February 5, 2003 that, in his opinion, it would be “perfectly appropriate” to use riot-control agents in some situations that soldiers would likely face. He used examples of enemy forces hiding in caves, barricaded in buildings, or intermixed with non-combatants. “You would prefer to get at [the soldiers] without also getting at women and children, or non-combatants,” he explained. These were all situations that American soldiers faced during the Vietnam War and were often able to resolve with tear gas. The need for these weapons became even more acute when US forces prepared to enter Baghdad in the final days of the war. As one reporter put it:

the potential use of tear gas in the war’s pending assault into the urban jungle [of Baghdad’s streets] has become a salient issue for Coalition commanders. US forces learned in the bloody Vietnam battle of Hue City that the judicious use of tear gas is a lifesaver when clearing close quarters of the enemy.¹

Riot-control agents are chemical compounds that cause intense irritation and produce transient incapacitation. There are two general categories within this class of agents. The principle effects from exposure to the first class are uncontrollable lacrimation along with some difficulty drawing a deep breath. These materials are often simply referred to as tear gases. Effects from exposure occur almost immediately, and end within minutes of escaping from the agent cloud. The two tear agents used during the Vietnam War were CN and CS.

In addition to tearing, the second class also causes sneezing, extreme headache, chills, nausea and sometimes even regurgitation. This group is usually referred to as vomiting agents. Unlike tear agents, the effects from these agents do not show up until several minutes after the initial exposure and can also persist for several hours. Individuals often report that they also experience severe depression during this extended recovery period. The only vomiting agent employed during the war was DM.

Although they produce transient incapacitation, these compounds should not be confused with the class of chemical weapons known as incapacitating agents. An agent from this latter group was used by Russian Special Forces during the 2002 hostage situation when Chechen guerrillas took over a Moscow theater. Incapacitating agents mainly produce their effects by altering or disrupting the higher regulatory activity of the central nervous system. They may induce delirium (producing confusion, hallucinations and disorganized behavior), stimulation (essentially flooding the brain with too much information), sedation (depressants that induce passivity or even sleep) or even psychosis (producing abnormal psychological effects resembling mental illness). Symptoms from exposure to these agents, as well as the onset and duration of the effects, vary greatly with dosage and are difficult to predict on a battlefield. The only incapacitating agent in the US arsenal during the war was BZ, a powdered material that caused delirium lasting from two to five days.²

The agents and munitions used in Vietnam had their roots in World War I. The very first attempt to use tear gas on a modern battlefield occurred in August 1914 when several Parisian police officers serving in the French Army fired 0.26-caliber bullets filled with ethyl bromoacetate into the German positions. For a number of years prior to the war, the Paris police department had been using these weapons against barricaded criminals who refused to surrender. Although these cartouches suffocantes produced good results inside a building, they were too small to be effective outdoors. Still the idea caught on and soon both sides were using tear gases to harass and wear down opposing soldiers.

To counter the effects of these and other chemical agents, the belligerents began wearing gas masks. Throughout the war there was a continual race between developing new agents and developing new masks and filters to counter their effects. Toward the end of the war, German researchers once again discovered a new class of agents, one they hoped would defeat the Allied masks. These “mask breakers” were actually non-volatile solids that had to be delivered as aerosols of micro-fine particles. Such particles were not absorbed by the charcoal in the filter elements used at that time and soldiers inhaled them with every breath. These agents caused violent sneezing and uncontrollable vomiting, thus forcing the affected soldier to remove his mask. When he did, he was exposed to other lethal agents that were fired on the target at the same time. Although the Germans used them extensively during the last year of the war, the design of their artillery shells was not effective at aerosolizing the powdered material. But even if they had solved the delivery issues, the results would have been a disappointment because the Allies had added a particulate filter to their masks.

Recognizing the potential of these vomiting agents, the Allies tried to synthesize their own. Unable to replicate the complex manufacturing process needed to produce the German agents, American researchers discovered a compound that was simpler to make and even more effective. Initially named for the American chemist who first synthesized it, adamsite eventually became known by the military code DM.

Concurrent with this discovery was the development of a new British munition that effectively generated a highly concentrated aerosol of properly sized particles. Known as the M device, it used a pyrotechnic mixture to generate hot gases that passed through the agent and distilled it into the atmosphere. As they left the canister, the vapors cooled and rapidly condensed into microscopic particles that remained suspended in the exhaust cloud. Filled with adamsite, the M device was a very potent weapon. However, the war ended before the Allies could get them into the field.

After the war, the fledgling security industry in the United States began offering police departments an assortment of weapons containing a variety of agent combinations. Unable to survive on the police market alone, these companies expanded their services and developed a host of novel products that they marketed directly to banks, armored car services and even individual citizens. The spectrum ranged from large systems that instantaneously flooded an entire room with gas to dual-purpose pens and mechanical pencils for personal protection.

Militaries around the world continued to pursue chemical programs and there were several conflicts before World War II, such as the Italian war with Ethiopia and Spanish colonization efforts in Morocco, when chemical agents and tear gases were used. Although the European powers did not use chemical weapons during World War II, the Japanese began using them against the Chinese as early as 1937. Along with lethal chemicals, they frequently used irritants to suppress enemy machine gun and artillery fire, as well as to disorganize enemy defenses prior to an attack. Unable to protect themselves or respond in kind, the Chinese could only plead with the rest of the world for support. In 1943, President Roosevelt issued a statement condemning the Japanese and threatening US retaliation in kind if they continued to use chemical weapons. Fearful of precipitating a full-scale chemical war that they did not think they could win, the Japanese acquiesced.

When the Korean War started, there were advocates on both sides of the chemical warfare issue. Many frontline commanders thought gas would be very beneficial against human wave attacks and for dealing with enemy soldiers hiding in the rough, mountainous terrain. Ultimately, no chemical weapons were used during the war except for limited application of tear gas as a means of subduing rioting prisoners of war.³

Over the years, various bodies and international conventions have tried to restrict the use of chemical weapons. At the time of the Vietnam War, the most successful was the 1925 Geneva Protocol. This document codified a common repugnance for these types of weapons and banned “the use in war of asphyxiating, poisonous or other gases, and of all analogous liquids, materials or devices.” Despite this lofty proclamation, most signatories filed reservations when they deposited their ratifications stipulating that they could retaliate in kind if chemical weapons were used against them. A number also held that the restraints against chemical warfare were only valid between the actual signatories to the treaty. Mussolini, for example, used variants of both of these arguments to justify using chemical weapons in Ethiopia. In a practical sense, the Geneva Protocol was only a no-first-use agreement between the signatories that did not limit the development or stockpiling of chemical weapons.

When it had the chance to ratify the Protocol in 1926, the United States Senate refused because they were convinced other countries would continue to clandestinely stockpile chemical weapons and these weapons would undoubtedly be used in the next war regardless of the treaty. Forty years later, the United States was still not a signatory. Based on this failure, Washington was able to maintain throughout the Vietnam War that the US was not a signatory to any treaty or agreement that limited its use of riot-control agents in combat.

The present work chronicles the events surrounding the use of these agents in combat and evaluates the evolution of the weapons and tactics used to deliver them. This study provides an opportunity to determine if riot-control agents actually offer any real advantages on the battlefield and if there were any situations for which they were uniquely suited. It also provides some insight into the attitudes of soldiers, civilians, the press and politicians concerning their use, and the changes in each over the course of the war. Further, it offers an excellent case study to examine one of the key questions that is often debated when chemical warfare is discussed. Does the availability and widespread use of tear gas necessarily weaken the constraints on escalation to unrestricted chemical warfare? Since there have been allegations that the US did use other classes of chemical weapons, including nerve agents, did the US in fact slide down that slippery slope? If not, what were the influences that prevented the escalation? The answers to these questions bear relevance for future conflicts as the nature of wars continue to change and the need for less than lethal options becomes even more critical.

2

PRELUDE

The first chemical weapons used by Americans during the Vietnam War were herbicides. Although not directly connected to the eventual combat use of riot-control agents, it is critical to understand the decision-making process; the concern over public perception; and the response to the Communist propaganda campaign in order to put the events surrounding the initial use of riot-control agents in perspective.

The program began when President John Kennedy authorized the military to begin testing aerial application of herbicides as a means of increasing visibility in the dense jungle vegetation to reduce the potential of enemy ambushes. On August 10, 1961, the Combat Development and Test Center in Vietnam ran the first defoliation test by applying herbicides to a small patch of jungle using specially outfitted helicopters. Two weeks later, they conducted a second test on a larger section of jungle, but this time they used airplanes so they could increase the rate of application. In both cases, the targets were personally selected by South Vietnamese President Ngo Dinh Diem. Although the American evaluation team was not overly impressed with the results, they made a big impact on Diem and he became an enthusiastic supporter of the program.¹

On September 29, shortly after the initial defoliation test, President Diem asked US representatives about using chemicals to destroy enemy food crops that being grown in remote, hard to reach regions of the country. The South Vietnamese Air Force had been trying unsuccessfully to use antipersonnel bombs and rockets to either destroy the crops or to drive off the Viet Cong tending the fields. President Diem told the envoys that he had heard the US had a “special powder” that would destroy the rice, but that President Kennedy had to personally authorize its use.² When he was informed that such materials were highly controlled and would not be approved for use in Vietnam, he became animated and declared that he did not care what was used as long as he could destroy the enemy’s crops.³

The proposal to employ defoliants on a widespread basis, especially to destroy enemy food crops, caused a serious controversy in Washington. Although members of the Administration generally agreed that using herbicides did not violate any rule of international law, and even destruction of enemy food stores was an accepted tactic of war, many did not believe that it was worth the potential negative press and public outcry.⁴ Ultimately, the question came down to whether the potential military tactical and strategic gains were worth the possible adverse propaganda and the subsequent damage to US long-term goals in the region. The destruction of food in a country that was suffering from a food shortage was seen as a particularly sensitive issue. Everyone involved recognized that the negative propaganda associated with crop destruction would be greater and harder to handle than any outcry associated with defoliation operations undertaken to reduce the capability of the enemy to ambush American soldiers.⁵

The Administration wanted to avoid anything that gave the impression that the US was resorting to biological or chemical warfare. Robert Johnson of the National Security Council Staff suggested to Deputy Special Assistant Walt Rostow that, “we must make the general character of the operations as open and above board as possible. Publicity ought to emphasize … that the chemical agents involved are the same kind that are used by farmers against weeds.” As the discussions continued, Under Secretary of State for Political Affairs Alexis Johnson advised Secretary of State Dean Rusk that “[w]e must also stay away from the term ‘chemical warfare’ and any connection with the Chemical Corps, and rather talk about ‘weed killers’. Defense and the Chemical Corps entirely agree on this.” They were afraid of a repeat of what Paul Neilson of the US Information Agency described as “the propaganda circus created by the communists on alleged US use of ‘germ warfare’ [during the Korean War].” He, along with many others in the Administration, was haunted by “the specter of charges that ‘US imperialists are waging germ warfare on Asians’.”⁶

During the Korean War, the Communists had charged the United States with using biological weapons, including agents that caused plague, anthrax, typhus and cholera.⁷ The diseases were allegedly spread by dropping leaflet bombs filled with contaminated feathers and balls of cotton, or insect vectors such as flies, fleas and ticks instead of the usual propaganda flyers. The allegations began in 1952 after several outbreaks of cholera and plague occurred inside North Korea. The Communists immediately launched a vehement propaganda campaign, railing against the US in the press and even elevating the issue to the United Nations. Despite an equally passionate refutation, the United States was never able to unequivocally clear itself of the cloud caused by the charges, which lingered on into the Vietnam War.⁸

The controversy over crop destruction peaked in the summer of 1962. On July 28, the Joint Chiefs of Staff sent a memorandum to Secretary of Defense McNamara stating that crop destruction would give the South Vietnamese Army a substantial military advantage over the guerrillas. After careful review, McNamara concurred with their conclusion and sent a recommendation to the President that the United States initiate a pilot program to see if it was plausible to destroy enemy crops with herbicides sprayed from aircraft. Since he was still worried about the potential damage that a Communist propaganda campaign might have on the international image of the United States, McNamara nuanced his recommendation with the caveat that American participation should remain as unobtrusive as possible and be limited to technical advice and assistance. He emphasized that all of the operational aspects, especially piloting the delivery aircraft, had to be handled by the South Vietnamese.⁹

As the military was preparing to move forward with both facets of the herbicide program, Rachel Carson published her seminal series of articles on the environment in the New Yorker. Although she never intended for them to be a commentary on the war, the Administration took note of their potential to start a grassroots outcry against the possible environmental and social impacts of deforestation and anti-crop operations. On August 16, Edward Murrow, Direc...

Table of contents

• Cover
• Title
• Copyright
• Dedication
• Contents
• Acknowledgments
• 1 Introduction
• 2 Prelude
• 3 Operation Stomp
• 4 Tunnels
• 5 Escalation
• 6 Niches
• 7 Urban combat
• 8 Communist Chemical Operations
• 9 Conclusion
• Appendix A Technical agent data
• Appendix B US munitions and weapon systems
• Appendix C Viet Cong improvised munitions
• Appendix D Protective masks
• Notes
• Selected Bibliography
• Index