Chemical warfare (CW) involves using the toxic properties of chemical substances as weapons. This type of warfare is distinct from nuclear warfare and biological warfare, which together make up NBC, the military acronym for nuclear, biological, and chemical (warfare or weapons), all of which are considered "weapons of mass destruction" (WMDs). None of these fall under the term conventional weapons which are primarily effective due to their destructive potential. In theory, with proper protective equipment, training, and decontamination measures, the primary effects of chemical weapons can be overcome. In practice, they continue to cause much suffering, as most victims are defenseless civilians. Many nations possess vast stockpiles of weaponized agents in preparation for wartime use. The threat and the perceived threat have become strategic tools in planning both measures and counter-measures.
Chemical warfare is different from the use of conventional weapons or nuclear weapons because the destructive effects of chemical weapons are not primarily due to any explosive force. The offensive use of living organisms (such as anthrax) is considered biological warfare rather than chemical warfare; however, the use of nonliving toxic products produced by living organisms (e.g. toxins such as botulinum toxin, ricin, and saxitoxin) is considered chemical warfare under the provisions of the Chemical Weapons Convention (CWC). Under this Convention, any toxic chemical, regardless of its origin, is considered a chemical weapon unless it is used for purposes that are not prohibited (an important legal definition known as the General Purpose Criterion).
About 70 different chemicals have been used or stockpiled as chemical warfare agents during the 20th century. The entire class known as Lethal Unitary Chemical Agents and Munitions have been scheduled for elimination by the CWC.
Under the Convention, chemicals that are toxic enough to be used as chemical weapons, or that may be used to manufacture such chemicals, are divided into three groups according to their purpose and treatment:
Chemical weapons have been a part of warfare in most societies, although their use has been particularly controversial since the 20th century.
|Wind dispersal||Gas masks, urinated-on gauze||Smell|
|1918||Lewisite||Chemical shells||Gas mask
Rosin oil clothing
|smell of geraniums|
|1920s||Projectiles w/ central bursters||CC-2 clothing|
|1930s||G-series nerve agents||Aircraft bombs||Blister agent detectors|
Color change paper
|Protective ointment (mustard)
Gas mask w/ Whetlerite
|1960s||V-series nerve agents||Aerodynamic||Gas mask w/ water supply||Nerve gas alarm|
|1980s||Binary munitions||Improved gas masks
(protection, fit, comfort)
|1990s||Novichok nerve agents|
Initially, only well-known commercially available chemicals and their variants were used. These included chlorine and phosgene gas. The methods used to disperse these agents during battle were relatively unrefined and inefficient. Even so, casualties could be heavy, due to the mainly static troop positions which were characteristic features of trench warfare.
Germany, the first side to employ chemical warfare on the battlefield, simply opened canisters of chlorine upwind of the opposing side and let the prevailing winds do the dissemination. Soon after, the French modified artillery munitions to contain phosgene - a much more effective method that became the principal means of delivery.
Since the development of modern chemical warfare in World War I, nations have pursued research and development on chemical weapons that falls into four major categories: new and more deadly agents; more efficient methods of delivering agents to the target (dissemination); more reliable means of defense against chemical weapons; and more sensitive and accurate means of detecting chemical agents.
A chemical used in warfare is called a chemical warfare agent (CWA). About 70 different chemicals have been used or stockpiled as chemical warfare agents during the 20th and 21st centuries. These agents may be in liquid, gas or solid form. Liquid agents that evaporate quickly are said to be volatile or have a high vapor pressure. Many chemical agents are made volatile so they can be dispersed over a large region quickly.
The earliest target of chemical warfare agent research was not toxicity, but development of agents that can affect a target through the skin and clothing, rendering protective gas masks useless. In July 1917, the Germans employed mustard gas. Mustard gas easily penetrates leather and fabric to inflict painful burns on the skin.
Chemical warfare agents are divided into lethal and incapacitating categories. A substance is classified as incapacitating if less than 1/100 of the lethal dose causes incapacitation, e.g., through nausea or visual problems. The distinction between lethal and incapacitating substances is not fixed, but relies on a statistical average called the LD50.
Chemical warfare agents can be classified according to their persistency, a measure of the length of time that a chemical agent remains effective after dissemination. Chemical agents are classified as persistent or nonpersistent.
Agents classified as nonpersistent lose effectiveness after only a few minutes or hours or even only a few seconds. Purely gaseous agents such as chlorine are nonpersistent, as are highly volatile agents such as sarin. Tactically, nonpersistent agents are very useful against targets that are to be taken over and controlled very quickly.
Apart from the agent used, the delivery mode is very important. To achieve a nonpersistent deployment, the agent is dispersed into very small droplets comparable with the mist produced by an aerosol can. In this form not only the gaseous part of the agent (around 50%) but also the fine aerosol can be inhaled or absorbed through pores in the skin.
Modern doctrine requires very high concentrations almost instantly in order to be effective (one breath should contain a lethal dose of the agent). To achieve this, the primary weapons used would be rocket artillery or bombs and large ballistic missiles with cluster warheads. The contamination in the target area is only low or not existent and after four hours sarin or similar agents are not detectable anymore.
By contrast, persistent agents tend to remain in the environment for as long as several weeks, complicating decontamination. Defense against persistent agents requires shielding for extended periods of time. Non-volatile liquid agents, such as blister agents and the oily VX nerve agent, do not easily evaporate into a gas, and therefore present primarily a contact hazard.
The droplet size used for persistent delivery goes up to 1 mm increasing the falling speed and therefore about 80% of the deployed agent reaches the ground, resulting in heavy contamination. Deployment of persistent agents is intended to constrain enemy operations by denying access to contaminated areas.
Possible targets include enemy flank positions (averting possible counterattacks), artillery regiments, commando posts or supply lines. Because it is not necessary to deliver large quantities of the agent in a short period of time, a wide variety of weapons systems can be used.
A special form of persistent agents are thickened agents. These comprise a common agent mixed with thickeners to provide gelatinous, sticky agents. Primary targets for this kind of use include airfields, due to the increased persistency and difficulty of decontaminating affected areas.
Chemical weapons are inert agents that come in four categories: choking, blister, blood and nerve. The agents are organized into several categories according to the manner in which they affect the human body. The names and number of categories varies slightly from source to source, but in general, types of chemical warfare agents are as follows:
|Class of agent||Agent Names||Mode of Action||Signs and Symptoms||Rate of action||Persistency|
|Nerve||Inactivates enzyme acetylcholinesterase, preventing the breakdown of the neurotransmitter acetylcholine in the victim's synapses and causing both muscarinic and nicotinic effects||
||VX is persistent and a contact hazard; other agents are non-persistent and present mostly inhalation hazards.|
|Asphyxiant/Blood||Immediate onset||Non-persistent and an inhalation hazard.|
|Vesicant/Blister||Agents are acid-forming compounds that damages skin and respiratory system, resulting burns and respiratory problems.||
||Persistent and a contact hazard.|
|Choking/Pulmonary||Similar mechanism to blister agents in that the compounds are acids or acid-forming, but action is more pronounced in respiratory system, flooding it and resulting in suffocation; survivors often suffer chronic breathing problems.||Immediate to 3 hours||Non-persistent and an inhalation hazard.|
|Lachrymatory agent||Causes severe stinging of the eyes and temporary blindness.||Powerful eye irritation||Immediate||Non-persistent and an inhalation hazard.|
||Causes atropine-like inhibition of acetylcholine in subject. Causes peripheral nervous system effects that are the opposite of those seen in nerve agent poisoning.||
||Extremely persistent in soil and water and on most surfaces; contact hazard.|
Non-living biological proteins, such as:
|Inhibit protein synthesis||4-24 hours; see symptoms. Exposure by inhalation or injection causes more pronounced signs and symptoms than exposure by ingestion||Slight; agents degrade quickly in environment|
There are other chemicals used militarily that are not scheduled by the Chemical Weapons Convention, and thus are not controlled under the CWC treaties. These include:
Most chemical weapons are assigned a one- to three-letter "NATO weapon designation" in addition to, or in place of, a common name. Binary munitions, in which precursors for chemical warfare agents are automatically mixed in shell to produce the agent just prior to its use, are indicated by a "-2" following the agent's designation (for example, GB-2 and VX-2).
Some examples are given below:
|Pulmonary agents:||Incapacitating agents:|
|Lachrymatory agents:||Nerve agents:|
The most important factor in the effectiveness of chemical weapons is the efficiency of its delivery, or dissemination, to a target. The most common techniques include munitions (such as bombs, projectiles, warheads) that allow dissemination at a distance and spray tanks which disseminate from low-flying aircraft. Developments in the techniques of filling and storage of munitions have also been important.
Although there have been many advances in chemical weapon delivery since World War I, it is still difficult to achieve effective dispersion. The dissemination is highly dependent on atmospheric conditions because many chemical agents act in gaseous form. Thus, weather observations and forecasting are essential to optimize weapon delivery and reduce the risk of injuring friendly forces.
Dispersion is placing the chemical agent upon or adjacent to a target immediately before dissemination, so that the material is most efficiently used. Dispersion is the simplest technique of delivering an agent to its target. The most common techniques are munitions, bombs, projectiles, spray tanks and warheads.
World War I saw the earliest implementation of this technique. The actual first chemical ammunition was the French 26 mm cartouche suffocante rifle grenade, fired from a flare carbine. It contained 35g of the tear-producer ethyl bromoacetate, and was used in autumn 1914 - with little effect on the Germans.
The Germans on the other hand tried to increase the effect of 10.5 cm shrapnel shells by adding an irritant - dianisidine chlorosulfonate. Its use went unnoticed by the British when it was used against them at Neuve Chapelle in October 1914. Hans Tappen, a chemist in the Heavy Artillery Department of the War Ministry, suggested to his brother, the Chief of the Operations Branch at German General Headquarters, the use of the tear-gases benzyl bromide or xylyl bromide.
Shells were tested successfully at the Wahn artillery range near Cologne on January 9, 1915, and an order was placed for 15 cm howitzer shells, designated 'T-shells' after Tappen. A shortage of shells limited the first use against the Russians at Bolimów on January 31, 1915; the liquid failed to vaporize in the cold weather, and again the experiment went unnoticed by the Allies.
The first effective use were when the German forces at the Second Battle of Ypres simply opened cylinders of chlorine and allowed the wind to carry the gas across enemy lines. While simple, this technique had numerous disadvantages. Moving large numbers of heavy gas cylinders to the front-line positions from where the gas would be released was a lengthy and difficult logistical task.
Stockpiles of cylinders had to be stored at the front line, posing a great risk if hit by artillery shells. Gas delivery depended greatly on wind speed and direction. If the wind was fickle, as at Loos, the gas could blow back, causing friendly casualties.
Gas clouds gave plenty of warning, allowing the enemy time to protect themselves, though many soldiers found the sight of a creeping gas cloud unnerving. This made the gas doubly effective, as, in addition to damaging the enemy physically, it also had a psychological effect on the intended victims.
Another disadvantage was that gas clouds had limited penetration, capable only of affecting the front-line trenches before dissipating. Although it produced limited results in World War I, this technique shows how simple chemical weapon dissemination can be.
Shortly after this "open canister" dissemination, French forces developed a technique for delivery of phosgene in a non-explosive artillery shell. This technique overcame many of the risks of dealing with gas in cylinders. First, gas shells were independent of the wind and increased the effective range of gas, making any target within reach of guns vulnerable. Second, gas shells could be delivered without warning, especially the clear, nearly odorless phosgene- there are numerous accounts of gas shells, landing with a "plop" rather than exploding, being initially dismissed as dud high explosive or shrapnel shells, giving the gas time to work before the soldiers were alerted and took precautions.
The major drawback of artillery delivery was the difficulty of achieving a killing concentration. Each shell had a small gas payload and an area would have to be subjected to saturation bombardment to produce a cloud to match cylinder delivery. A British solution to the problem was the Livens Projector. This was effectively a large-bore mortar, dug into the ground that used the gas cylinders themselves as projectiles - firing a 14 kg cylinder up to 1500 m. This combined the gas volume of cylinders with the range of artillery.
Over the years, there were some refinements in this technique. In the 1950s and early 1960s, chemical artillery rockets and cluster bombs contained a multitude of submunitions, so that a large number of small clouds of the chemical agent would form directly on the target.
Thermal dissemination is the use of explosives or pyrotechnics to deliver chemical agents. This technique, developed in the 1920s, was a major improvement over earlier dispersal techniques, in that it allowed significant quantities of an agent to be disseminated over a considerable distance. Thermal dissemination remains the principal method of disseminating chemical agents today.
Thermal dissemination devices, though common, are not particularly efficient. First, a percentage of the agent is lost by incineration in the initial blast and by being forced onto the ground. Second, the sizes of the particles vary greatly because explosive dissemination produces a mixture of liquid droplets of variable and difficult to control sizes.
The efficacy of thermal detonation is greatly limited by the flammability of some agents. For flammable aerosols, the cloud is sometimes totally or partially ignited by the disseminating explosion in a phenomenon called flashing. Explosively disseminated VX will ignite roughly one third of the time. Despite a great deal of study, flashing is still not fully understood, and a solution to the problem would be a major technological advance.
Despite the limitations of central bursters, most nations use this method in the early stages of chemical weapon development, in part because standard munitions can be adapted to carry the agents.
Aerodynamic dissemination is the non-explosive delivery of a chemical agent from an aircraft, allowing aerodynamic stress to disseminate the agent. This technique is the most recent major development in chemical agent dissemination, originating in the mid-1960s.
This technique eliminates many of the limitations of thermal dissemination by eliminating the flashing effect and theoretically allowing precise control of particle size. In actuality, the altitude of dissemination, wind direction and velocity, and the direction and velocity of the aircraft greatly influence particle size. There are other drawbacks as well; ideal deployment requires precise knowledge of aerodynamics and fluid dynamics, and because the agent must usually be dispersed within the boundary layer (less than 200-300 ft above the ground), it puts pilots at risk.
Significant research is still being applied toward this technique. For example, by modifying the properties of the liquid, its breakup when subjected to aerodynamic stress can be controlled and an idealized particle distribution achieved, even at supersonic speed. Additionally, advances in fluid dynamics, computer modeling, and weather forecasting allow an ideal direction, speed, and altitude to be calculated, such that warfare agent of a predetermined particle size can predictably and reliably hit a target.
Ideal protection begins with nonproliferation treaties such as the Chemical Weapons Convention, and detecting, very early, the signatures of someone building a chemical weapons capability. These include a wide range of intelligence disciplines, such as economic analysis of exports of dual-use chemicals and equipment, human intelligence (HUMINT) such as diplomatic, refugee, and agent reports; photography from satellites, aircraft and drones (IMINT); examination of captured equipment (TECHINT); communications intercepts (COMINT); and detection of chemical manufacturing and chemical agents themselves (MASINT).
If all the preventive measures fail and there is a clear and present danger, then there is a need for detection of chemical attacks, collective protection, and decontamination. Since industrial accidents can cause dangerous chemical releases (e.g., the Bhopal disaster), these activities are things that civilian, as well as military, organizations must be prepared to carry out. In civilian situations in developed countries, these are duties of HAZMAT organizations, which most commonly are part of fire departments.
Detection has been referred to above, as a technical MASINT discipline; specific military procedures, which are usually the model for civilian procedures, depend on the equipment, expertise, and personnel available. When chemical agents are detected, an alarm needs to sound, with specific warnings over emergency broadcasts and the like. There may be a warning to expect an attack.
If, for example, the captain of a US Navy ship believes there is a serious threat of chemical, biological, or radiological attack, the crew may be ordered to set Circle William, which means closing all openings to outside air, running breathing air through filters, and possibly starting a system that continually washes down the exterior surfaces. Civilian authorities dealing with an attack or a toxic chemical accident will invoke the Incident Command System, or local equivalent, to coordinate defensive measures.
Individual protection starts with a gas mask and, depending on the nature of the threat, through various levels of protective clothing up to a complete chemical-resistant suit with a self-contained air supply. The US military defines various levels of MOPP (mission-oriented protective posture) from mask to full chemical resistant suits; Hazmat suits are the civilian equivalent, but go farther to include a fully independent air supply, rather than the filters of a gas mask.
Collective protection allows continued functioning of groups of people in buildings or shelters, the latter which may be fixed, mobile, or improvised. With ordinary buildings, this may be as basic as plastic sheeting and tape, although if the protection needs to be continued for any appreciable length of time, there will need to be an air supply, typically an enhanced gas mask.
Decontamination varies with the particular chemical agent used. Some nonpersistent agents, including most pulmonary agents (chlorine, phosgene, and so on), blood gases, and nonpersistent nerve gases (e.g., GB), will dissipate from open areas, although powerful exhaust fans may be needed to clear out buildings where they have accumulated.
In some cases, it might be necessary to neutralize them chemically, as with ammonia as a neutralizer for hydrogen cyanide or chlorine. Riot control agents such as CS will dissipate in an open area, but things contaminated with CS powder need to be aired out, washed by people wearing protective gear, or safely discarded.
Mass decontamination is a less common requirement for people than equipment, since people may be immediately affected and treatment is the action required. It is a requirement when people have been contaminated with persistent agents. Treatment and decontamination may need to be simultaneous, with the medical personnel protecting themselves so they can function.
There may need to be immediate intervention to prevent death, such as injection of atropine for nerve agents. Decontamination is especially important for people contaminated with persistent agents; many of the fatalities after the explosion of a WWII US ammunition ship carrying mustard gas, in the harbor of Bari, Italy, after a German bombing on December 2, 1943, came when rescue workers, not knowing of the contamination, bundled cold, wet seamen in tight-fitting blankets.
For decontaminating equipment and buildings exposed to persistent agents, such as blister agents, VX or other agents made persistent by mixing with a thickener, special equipment and materials might be needed. Some type of neutralizing agent will be needed; e.g. in the form of a spraying device with neutralizing agents such as Chlorine, Fichlor, strong alkaline solutions or enzymes. In other cases, a specific chemical decontaminant will be required.
The study of chemicals and their military uses was widespread in China and India. The use of toxic materials has historically been viewed with mixed emotions and moral qualms in the West. The practical and ethical problems surrounding poison warfare appeared in ancient Greek myths about Hercules' invention of poison arrows and Odysseus's use of toxic projectiles. There are many instances of the use of chemical weapons in battles documented in Greek and Roman historical texts; the earliest example was the deliberate poisoning of Kirrha's water supply with hellebore in the First Sacred War, Greece, about 590 BC.
One of the earliest reactions to the use of chemical agents was from Rome. Struggling to defend themselves from the Roman legions, Germanic tribes poisoned the wells of their enemies, with Roman jurists having been recorded as declaring "armis bella non venenis geri", meaning "war is fought with weapons, not with poisons." Yet the Romans themselves resorted to poisoning wells of besieged cities in Anatolia in the 2nd century BCE.
Before 1915 the use of poisonous chemicals in battle was typically the result of local initiative, and not the result of an active government chemical weapons program. There are many reports of the isolated use of chemical agents in individual battles or sieges, but there was no true tradition of their use outside of incendiaries and smoke. Despite this tendency, there have been several attempts to initiate large-scale implementation of poison gas in several wars, but with the notable exception of World War I, the responsible authorities generally rejected the proposals for ethical reasons.
For example, in 1854 Lyon Playfair (later 1st Baron Playfair, GCB, PC, FRS (May 1, 1818 - May 29, 1898), a British chemist, proposed using a cacodyl cyanide-filled artillery shell against enemy ships during the Crimean War. The British Ordnance Department rejected the proposal as "as bad a mode of warfare as poisoning the wells of the enemy."
|Countries with known or possible chemical weapons, as of 2013[needs update]|
|Nation||CW Possession||Signed CWC||Ratified CWC|
|Albania||Known||January 14, 1993||May 11, 1994|
|Burma (Myanmar)||Possible||January 14, 1993||July 8, 2015|
|China||Probable||January 13, 1993||April 4, 1997|
|India||Known||January 14, 1993||September 3, 1996|
|Iran||Known||January 13, 1993||November 3, 1997|
|Israel||Probable||January 13, 1993||No|
|Japan||Probable||January 13, 1993||September 15, 1995|
|Libya||Known||No||January 6, 2004 |
|Pakistan||Probable||January 13, 1993||October 28, 1997|
|Russia||Known||January 13, 1993||November 5, 1997|
|Probable||No||April 20, 2000 |
|Sudan||Possible||No||May 24, 1999 |
|Syria||Known||No||September 14, 2013 |
|United States||Known||January 13, 1993||April 25, 1997|
|Vietnam||Probable||January 13, 1993||September 30, 1998|
Despite numerous efforts to reduce or eliminate them, some nations continue to research and/or stockpile chemical warfare agents. To the right is a summary of the nations that have either declared weapon stockpiles or are suspected of secretly stockpiling or possessing CW research programs. Notable examples include United States and Russia.
In 1997, future US Vice President Dick Cheney opposed the signing ratification of a treaty banning the use chemical weapons, a recently unearthed letter shows. In a letter dated April 8, 1997, then Halliburton-CEO Cheney told Sen. Jesse Helms, the chairman of the Senate Foreign Relations Committee, that it would be a mistake for America to join the Convention. "Those nations most likely to comply with the Chemical Weapons Convention are not likely to ever constitute a military threat to the United States. The governments we should be concerned about are likely to cheat on the CWC, even if they do participate," reads the letter, published by the Federation of American Scientists.
The CWC was ratified by the Senate that same month. Since then, Albania, Libya, Russia, the United States, and India have declared over 71,000 metric tons of chemical weapon stockpiles, and destroyed about a third of them. Under the terms of the agreement, the United States and Russia agreed to eliminate the rest of their supplies of chemical weapons by 2012. Not having met its goal, the U.S. government estimates remaining stocks will be destroyed by 2017.[needs update]
In June 1997, India declared that it had a stockpile of 1044 tons of sulphur mustard in its possession. India's declaration of its stockpile came after its entry into the Chemical Weapons Convention, that created the Organisation for the Prohibition of Chemical Weapons, and on January 14, 1993 India became one of the original signatories to the Chemical Weapons Convention. By 2005, from among six nations that had declared their possession of chemical weapons, India was the only country to meet its deadline for chemical weapons destruction and for inspection of its facilities by the Organisation for the Prohibition of Chemical Weapons. By 2006, India had destroyed more than 75 percent of its chemical weapons and material stockpile and was granted an extension to complete a 100 percent destruction of its stocks by April 2009. On May 14, 2009 India informed the United Nations that it has completely destroyed its stockpile of chemical weapons.
The Director-General of the Organisation for the Prohibition of Chemical Weapons, Ambassador Rogelio Pfirter, welcomed Iraq's decision to join the OPCW as a significant step to strengthening global and regional efforts to prevent the spread and use of chemical weapons. The OPCW announced "The government of Iraq has deposited its instrument of accession to the Chemical Weapons Convention with the Secretary General of the United Nations and within 30 days, on 12 February 2009, will become the 186th State Party to the Convention". Iraq has also declared stockpiles of chemical weapons, and because of their recent accession is the only State Party exempted from the destruction time-line.
During the Second Sino-Japanese War (1937-1945) Japan stored chemical weapons on the territory of mainland China. The weapon stock mostly containing mustard gas-lewisite mixture. The weapons are classified as abandoned chemical weapons under the Chemical Weapons Convention and from September 2010 Japan has started their destruction in Nanjing using mobile destruction facilities in order to do so.
Russia signed into the Chemical Weapons Convention on January 13, 1993 and ratified it on November 5, 1995. Declaring an arsenal of 39,967 tons of chemical weapons in 1997, by far the largest arsenal, consisting of blister agents: Lewisite, Sulfur mustard, Lewisite-mustard mix, and nerve agents: Sarin, Soman, and VX. Russia met its treaty obligations by destroying 1 percent of its chemical agents by the 2002 deadline set out by the Chemical Weapons Convention, but requested an extension on the deadlines of 2004 and 2007 due to technical, financial, and environmental challenges of chemical disposal. Since, Russia has received help from other countries such as Canada which donated C$100,000, plus a further C$100,000 already donated, to the Russian Chemical Weapons Destruction Program. This money will be used to complete work at Shchuch'ye and support the construction of a chemical weapons destruction facility at Kizner (Russia), where the destruction of nearly 5,700 tons of nerve agent, stored in approximately 2 million artillery shells and munitions, will be undertaken. Canadian funds are also being used for the operation of a Green Cross Public Outreach Office, to keep the civilian population informed on the progress made in chemical weapons destruction activities.
As of July 2011, Russia has destroyed 48 percent (18,241 tons) of its stockpile at destruction facilities located in Gorny (Saratov Oblast) and Kambarka (Udmurt Republic) - where operations have finished - and Schuch'ye (Kurgan Oblast), Maradykovsky (Kirov Oblast), Leonidovka (Penza Oblast) whilst installations are under construction in Pochep (Bryansk Oblast) and Kizner (Udmurt Republic). As August 2013, 76 percent (30,500 tons) were destroyed, and Russia leaves the Cooperative Threat Reduction (CTR) Program, which partially funded chemical weapons destruction.
On November 25, 1969, President Richard Nixon unilaterally renounced the use of chemical weapons and renounced all methods of biological warfare. He issued a decree halting the production and transport of all chemical weapons which remains in effect. From May 1964 to the early 1970s the USA participated in Operation CHASE, a United States Department of Defense program that aimed to dispose of chemical weapons by sinking ships laden with the weapons in the deep Atlantic. After the Marine Protection, Research, and Sanctuaries Act of 1972, Operation Chase was scrapped and safer disposal methods for chemical weapons were researched, with the U.S. destroying several thousand tons of mustard gas by incineration at the Rocky Mountain Arsenal, and nearly 4,200 tons of nerve agent by chemical neutralisation at Tooele Army Depot.
The U.S. ratified the Geneva Protocol which banned the use of chemical and biological weapons on January 22, 1975. In 1989 and 1990, the U.S. and the Soviet Union entered an agreement to both end their chemical weapons programs, including binary weapons. In April 1997, the United States ratified the Chemical Weapons Convention, this banned the possession of most types of chemical weapons. It also banned the development of chemical weapons, and required the destruction of existing stockpiles, precursor chemicals, production facilities, and their weapon delivery systems.
The U.S. began stockpile reductions in the 1980s with the removal of outdated munitions and destroying its entire stock of 3-Quinuclidinyl benzilate (BZ or Agent 15) at the beginning of 1988. In June 1990 the Johnston Atoll Chemical Agent Disposal System began destruction of chemical agents stored on the Johnston Atoll in the Pacific, seven years before the Chemical Weapons Treaty came into effect. In 1986 President Ronald Reagan made an agreement with the Chancellor, Helmut Kohl to remove the U.S. stockpile of chemical weapons from Germany. In 1990, as part of Operation Steel Box, two ships were loaded with over 100,000 shells containing Sarin and VX were taken from the U.S. Army weapons storage depots such as Miesau and then-classified FSTS (Forward Storage / Transportation Sites) and transported from Bremerhaven, Germany to Johnston Atoll in the Pacific, a 46-day nonstop journey.
In May 1991, President George H. W. Bush committed the United States to destroying all of its chemical weapons and renounced the right to chemical weapon retaliation. In 1993, the United States signed the Chemical Weapons Treaty, which required the destruction of all chemical weapon agents, dispersal systems, and production facilities by April 2012. The U.S. prohibition on the transport of chemical weapons has meant that destruction facilities had to be constructed at each of the U.S.'s nine storage facilities. The U.S. met the first three of the four deadlines set out in the treaty, destroying 45% of its stockpile of chemical weapons by 2007. Due to the destruction of chemical weapons, under the United States policy of Proportional Response, an attack upon the United States or its Allies would trigger a force-equivalent counter-attack. Since the United States only maintains nuclear Weapons of Mass Destruction, it is the stated policy that the United States will regard all WMD attacks (Biological, chemical, or nuclear) as a nuclear attack and will respond to such an attack with a nuclear strike.
As of 2012, stockpiles have been eliminated at 7 of the 9 chemical weapons depots and 89.75% of the 1997 stockpile has been destroyed by the treaty deadline of April 2012. Destruction will not begin at the two remaining depots until after the treaty deadline and will use neutralization, instead of incineration.
The use of herbicides as a chemical weapon by the U.S. military during the Vietnam War has left tangible, long-term impacts upon the Vietnamese people that live in Vietnam. For instance, it led to 3 million Vietnamese people suffering health problems, one million birth defects caused directly by exposure to Agent Orange, and 24% of the area of Vietnam being defoliated. The United States fought secret wars in Laos and Cambodia, dropping large quantities of Agent Orange in each of those countries. According on one estimate, the U.S. dropped 475,500 gallons of Agent Orange in Laos and 40,900 in Cambodia. Because Laos and Cambodia were neutral during the Vietnam War, the U.S. attempted to keep secret its wars, including its bombing campaigns against those countries, from the American population and has largely avoided recognizing the debilitating effects on the people exposed at the time and the major birth defects caused for generations that followed. It also avoided compensating American veterans and CIA personnel stationed in Cambodia and Laos who suffered permanent injuries as a result of exposure to Agent Orange there.