Non-lethal weapons: Novel tools for peacekeeping missions

  • Technical Articles
  • Jan 01,19
Non-lethal weapons (NLWs) are not likely to replace lethal weapons but will simply add another capability to the existing range of options, says Dr J P Agrawal.
Non-lethal weapons:  Novel tools for peacekeeping missions

Non-lethal weapons (NLWs) are not likely to replace lethal weapons but will simply add another capability to the existing range of options, says Dr J P Agrawal.
A weapon is a generic term for all devices/instruments which are used against an adversary or opponent and their function is to inflict harm/damage or kill/hurt them in a fight or war. Weapons may be lethal or non-lethal depending on chemicals employed and consist of: from a hand thrown grenade to a heavy artillery shell; pistal bullet to a high velocity kinetic energy anti-tank projectile and a simple illuminating rocket to an Inter Continental Ballistic Missile (ICBM). 
Lethal weapons are well known to all and are generally used during wars/conflicts. The traditional military weaponry was and is still designed to be lethal and its aim is to kill the adversary. The traditional lethal weapons use explosives such as RDX /Wax or RDX/TNT; HMX/Wax or HMX/ TNT or explosives of recent origin such as CL-20 and destroy targets principally through blast, penetration or fragmentation. 
Figure 1 shows some traditional lethal weapons. 
On the other hand, non-lethal weapons (NLWs) employ means other than gross destruction to prevent the targets from functioning (Anti-Material, AM) and incapacitating or repelling personnel (Anti-Personnel, AP). Different agencies use different terms for NLWs such as ‘less-lethal weapons’ (LLWs), ‘less-than-lethal weapons’ (LTLWs), ‘non-deadly weapons’ (NDWs), ‘compliance weapons’ (CWs), ‘pain-inducing weapons’ (PIWs), ‘low-collateral damage munitions’ (LCDMs), ‘disabling munitions’ (DMs), ‘non-lethal disabling technologies’ (NLDTs) etc. Sometimes, these terms are interchangeable. NLWs are intended to be less likely to kill a living target and try to minimise the risk as much as possible. These are used in policing combat situations to limit the escalation of conflicts where use of lethal weapons is prohibited/undesirable. The development of NLWs is a result of end of the cold war. Thus in a nutshell, the term NLWs covers a wide range of devices and technologies, both anti-personnel (AP) as well as anti-material (AM). In fact, any weapon can be non-lethal. For example, a gun can also be non-lethal if it is used to shoot someone’s foot or hand only or simply hit a target with the butt.  On the other hand, many supposed NLWs could be lethal if used incorrectly. For example, a rubber bullet can kill if fired too close to the target.
NATO policy on NLWs defines them as weapons which are explicitly designated and developed to incapacitate or repel personnel, with a low probability of fatality or permanent injury or to disable equipment, with minimal undesired damage or impact on the environment. NLWs are meant to complement the traditional lethal weapons already available at the disposal of NATO forces in order to achieve their goals.
Salient Characteristics of NLWs
NLWs should possess some essential as well as some desirable characteristics. 
Essential Characteristics: First and foremost, a NLW must function almost instantaneously at a reasonably safe distance i.e. it should not be too short considering safety of the user and not too long keeping in view the range of weapon. Also, a person affected by a NLW must recover with no lasting medical problems. A NLW must have universal application i.e. it must be able to function properly irrespective of any situation (inside or outside a building) and climate (cold, hot or rain) etc. The weapon must be portable so that it can be transported to the desired location easily and quickly. The effects caused by a NLW must be precise enough to affect the target and only the target without affecting innocent bystanders or bypassers or onlookers.
Desirable Characteristics: NLWs should be compatible with the existing weapon systems i.e. NLWs which can be delivered/launched using existing weapon systems are preferable. The use of NLWs should not alter/affect the environment adversely i.e. NLWs should be environment-friendly.
Differences between lethal and non-lethal weapons
NLWs are not simply kindlier or gentler version of lethal weapons but there are some fundamental differences in how they are defined and employed.
Lethal weapons are defined by their capability whereas NLWs are defined by their intent. A NLW employed in a manner that causes death is not a NLW. At the same time, a lethal weapon employed in a manner which does not cause death, can be defined as a NLW.
A lethal weapon attempts to defeat an adversary’s ability to fight whereas NLWs attempt to defeat his will to fight. Lethal weapons will kill an adversary definitely but there is no NLW currently available that assures of not killing an adversary.
NLWs will not replace lethal weapons but will always be considered adjuncts to lethal weapons available for Armed Forces during wars.
Advantages of NLWs
NLWs are used for riot control, prisoner control, crowd control, refugees control and self-defence. The NLWs provide more effective riot control than firearms, bayonets or truncheons with less risk of loss of life or serious injury. Forces that employ NLWs have the following advantages over the conventional lethal weapons:
  • The use of NLWs is less likely to provoke bystanders/onlookers and as a result, bystanders/onlookers are less likely to be sympathetic towards persons who defy peacekeeping forces.
  • The use of NLWs forces adversaries to show their intentions. Mostly, onlookers/bystanders simply run away the moment they come to know about the use of NLWs.
  • Another advantage of NLWs is that they provide an alternate to lethal weapons.
  • NLWs may be used in conjunction with lethal weapons to enhance their effectiveness.
  • NLWs are useful during military operations in urban areas where adversaries have an opportunity to blend/mix with civilian population.
  • The use of NLWs is more humane and allows commanders of forces (peacekeeping) with more flexibility and freedom of action.
  • All peacekeeping operations are controversial. However, the use of NLWs is less likely to raise any public outcry. 
Classification of NLWs
Based on the literature available in the public domain, a broad range of NLWs along with their brief description and primary target, are given in Table 1. The boundaries of their classification are not precise and some overlapping may be there in some cases. All NLWs currently available may be broadly grouped into 5 categories which are Acoustic; Biological/medical; Chemical; Electromagnetic; and Kinetic.
Acoustic NLWs
Acoustic NLWs are supposed to possess most ideal characteristics and incapacitate adversaries/opponents immediately with no lingering damage.High power very low frequency accelerating beams like infrasound can travel long distances and easily penetrate most buildings and vehicles. At the same time, it does not lose its properties when it changes medium i.e. from air to human tissues and creates biophysical effects (nausea, abdominal pain, loss of bowel control, vomiting, disorientation etc).
It is reported that an ‘Infrasound generator’ which generates waves at 7 Hz, was developed by Frenchs and made people sick for hours on its activation. Acoustic bullets and beams are also reported to be under development.
Biological/Medical NLWs
Some microbes are reported to convert aviation fuels  into a jelly. Also some microbes can be tailored to degrade even concrete and metals thus making them useful for NLWs. Calmatives are also known as sleep agents. Biotechnical 
agents such as fentanyls, Ketamines and Alfentinil  etc. are sedatives or sleep- inducing drugs when mixed with dimethyl sulphoxide (DMSO promotes absorption through skin quickly) and sedate contacted persons. It is reported that such calmatives were used by Soviets extensively against Mujahideens in Afghanistan.
Chemical NLWs
There are a large number of chemicals available for this purpose, mentioned in Table 1 and their brief description is given below:
Vomiting/tear gas/incapacitating agents or chemicals: The well known vomiting chemicals/agents: diphenylchloroarsine (DA), adamsite(diphenylaminochloroarsine (DM) and diphenylcyanoarsine (DC) are normally solids. When heated, these chemicals vaporise and condense to form aerosols and cause cold, sneezing,coughing, severe headache, acute pain, tightness in the chest, nausea and vomiting. Their rate of reaction is fast but the effectiveness of duration is short. These vomiting agents are primarily used for mob and riot control.
Tears producing agents or chemicals: CA (4-Bromobenzylcyanide) was one of the first tear gas agent used and produces a burning sensation of the mucus membrane, severe irritation and tearing of the eyes with acute pain in the forehead. It is, however, obsolete now.
The reaction of CN (w-Chloroacetophenone) is almost instantaneous and causes irritation to the eyes, upper respiratory passage in addition to the skin. CN incapacitates for about 3 minutes and is now replaced by CS. 
CS (O-Chlorobenzylidene malononitrile) was first used by USA in 1968 during the Washington, DC riots and incapacitates offenders within 5-10 minutes. CS is an effective riot control agent and is now the most commonly used tear gas agent and is more effective than CN. There are several CS based formulations: CS1 (free flowing powder consisting of 95% CS & 5% Silica aerogel), CS2 (CS blended with silicon- treated silica aerogel) and CSX (1% powdered CS + 99% trioctylphosphite, TOF dissolved in a liquid).
CS is preferred as a tear gas agent because it produces a whole range of unpleasant effects (coughing, vomiting and a burning sensation in the eyes) and at the same time, reasonably safe. US Army used CS extensively during the Vietnam War to derive enemy soldiers from deep caves, tunnels and bunkers for subsequent capture. It was also used extensively by the British Army in Northern Ireland but only for riot & crowd control.
CR [Dibenz-(b,f)-1,4-oxazepine] is a newer riot irritant developed in the UK in 1962 and is  about 5 times more effective than CS in addition to being  much less toxic. Pure CR is a yellow powder and is generally used in the form of a solution (0.1%) which is made in 80 parts of propylene glycol & 20 parts water. Eye pain, discomfort & excessive tearing occur and symptoms persist for about 15-20 minutes. It is however, more expensive than other tear gas agents.
The use of Buzz or BZ (3- Quinuclidinyl benzilate) depresses the central nervous system (CNS) resulting into vomiting, lethargy and loss of coordination of various parts of the body within an hour of exposure. However, its use is prohibited by the members of NATO countries.
OC (Oleoresin Capsicum)/pepper sprays have become very popular & a new NLW of choice for the US police. A solution is made using chilli peppers(dried & finely ground) with an emulsifier (mineral/vegetable/soya oil or water) and is sprayed from a dispenser and is used as an irritant for controlling violent mobs & maintenance of order. OC/pepper sprays are also very effective for self-defence. It is very easy to use them and, at the same time, are not expensive.
Super corrosives or super caustics chemicals: The term supercaustics is used to cover both supercorrosives (acids) as well as supercaustics (bases). The chemicals which are better than hydrofluoric acid (HF) are classified under this class of chemicals. For example, aqua regia is one of them. Aqua regia is a mixture of concentrated nitric acid (Conc. HNO3) & concentrated hydrochloric acid (Conc. HCl) in a molar ratio of 1:3. It is a yellow-orange fuming liquid and is also called Royal Water or King’s Water because of its ability to dissolve gold (Au), Platinum (Pt) and other noble metals. This also destroys organic substances such as plastics, rubbers and asphalt. Bases such as sodium hydroxide (NaOH), potassium hydroxide (KOH) and caesium hydroxide (CsOH) etc are used to attack glass in the optical systems. Therefore, supercaustics can be used to attack structures, armoured vehicles, roof tops and optical systems etc.
Liquid metal embrittlement (LME) chemicals/agents are metals or alloys which are liquid at near-normal temperatures and react with other metals readily. Such chemicals operate by altering molecular structure of base metals/alloys and interfere with the operation of aircrafts, vehicles, metal treads and bridge supports to which these chemicals are applied. Mercury, which alters the chemical structure of metal equipments resulting in their weakening, is an important example. Other examples are caesium, gallium and rubidium.
Slick Coatings Chemicals: The application of some lubricants/chemicals (teflon type) results into slippery surfaces which inhibit the free movement of a person/vehicle. It is almost impossible for a person to move/stand up on such treated surfaces. Even tyre-type vehicles are unable to get traction on such roads.
Sticky foams chemicals: It is also known as super-adhesives, super-glues or quick setting foam formulations which are generally polymer-based. These sticky foams coatings are very persistent and it is virtually impossible to remove them without a specified liquid solvent. It is reported that the US Marines used such foams in Mogadishu, Somalia to prevent armed intruders from impeding efforts to extricate UN forces from there. The roads & runways can also be made unusable by the application of such adhesives.
Chemical formulations for strong light & smoke: One of the basic purposes of using NLWs is to stun the offender/adversary. Weapons such as stun grenades/flash bangs create a blinding flash of light followed by a loud explosion. Similarly, creation of sudden obscuring smokes offer 
a way to achieve a distracting effect that is temporary & provide soldiers/police a tactical advantage in a stand-off scenario.
There are a number of pyrotechnic formulations which generate strong lights or smokes (white as well as coloured). US forces used ‘illuminating grenades’ in Vietnam War to produce strong light (25 K candle power for about 25 sec) and as a result, Vietnamese soldiers got blinded and were ultimately captured by the US forces. Similarly, white obscuring smoke is generated by smoke grenades/pots. This smoke is irritating to nose, throat and those affected lose visibility, sense of purpose and direction. White smokes are tactically ideal for police use. However, coloured smokes produce greater psychological & panic effect than white smokes because rioters confronted with coloured smokes feel that they are being marked and run away as quickly as possible.
Electromagnetic NLWs
Various types of lasers and tasers are classified under this category.
Lasers: Infra-red CO2 lasers & Eye safe low-energy lasers have been reported for this purpose. The former heats the skin of the offender to cause pain (not to burn skin) making it very useful against the hand of a suspect holding a knife/gun to a hostage whereas the latter (continuous wave laser) produces a high intensity glare which is strong enough to temporarily delay & disorient an offender. Some laser based weapons are capable of blinding the enemy momentarily.
Tasers: They are commercially available and used successfully to induce involuntary contradictions that incapacitate (unable to carry out their primary functions) people temporarily. This is a battery-powered, hand-held & portable device and fires 2- small barbed projectiles with thin trailing wires. A new electrical NLW known as Sticky Shockers (a self-contained wireless projectile) are also available and create the same effect as a taser but at a longer distance.
Kinetic NLWs
The devices which make use of bean bags, pellets, balls, nets, rubber & wooden baton rounds etc. are put under this category. These are:
Rubber ball grenades: These are also known as Sting Balls or Stinger Grenades. This is an explosive based anti-riot weapon which on ignition , hurtles a large number of small ‘stinging rubber balls at the rioters. In order to improve their performance, riot-control agents such as CN,CS,CR& OC etc. can be incorporated in these grenades.
Bean bags/flying bean bags/shot bags: The fabric bags are usually filled with lead shots and are fired using 12-gauge shot guns & 40 mm launchers. The bags are rolled in the cartridge and unroll on exiting the launch barrel. The bags confirm to the shape of the target on impact and produce less damage than a solid hard projectile. The hand-held and shoulder-launched 37 mm anti-riot device can also be used to launch rubber balls grenades and bean bags etc.
Nets: Nets are also beginning to come on the scene as an alternative for a variety of scenarios.
In case a single NLW does not meet the requirements of the law-enforcing agencies, 2/3 technologies may be combined together. The conventional deployment tactics suggest use of more than one NLW because limitation of one may be offset by another. For example, ‘pepper spray’ is highly effective but range is short. On the other hand, bean bags/shot bags are effective at greater ranges. Thus, by mounting a ‘pepper spray grenade’ on a bean bag launcher, a highly effective NLW may be obtained.
Some Well Known Non-lethal Weapons: There are several well known NLWs which are commercially available in India as well as other countries and their brief description, merits/demerits and manufactures are listed in Table 2.
NLWs are not likely to replace lethal weapons but will simply add another capability to the existing range of options. Further, NLWs are likely to play a greater role in preventing casualties among non-combatants during combats and this is regarded as a major advantage. Also, the successful use of such NLWs will significantly reduce the use of non-combatants as a cover/shield by the enemy forces. In a  Jammu & Kashmir (J&K) like situation where some local misguided youths are involved in stone pelting, forces need to perform their duties such as clearing buildings quickly & safely, dispersing crowds, isolating & catching terrorists with the help of NLWs and this is exactly the niche that a whole range of NLWs are expected to fill. 
Similarly, NLWs are expected to be very effective for controlling mob violence and lynching which is increasing in India. The sprays based on CN, CS, pepper, etc are considered a boon for ladies safety because their use is very simple and at the same time, these are not expensive.
Despite so many advantages of NLWs, there appears to be a major problem in their use i.e. it may deem to be contrary to Chemical Weapons Convention (CWC) which prohibits the development, production or retention of any chemical which causes death, temporary incapacitation or permanent harm to humans or animals. Further, CWC permits the use of incapacitating agents for riot control purposes but their use by military forces is forbidden. In addition, the Geneva Convention stipulates that NLWs should not cause undesired damage/unnecessary suffering especially to non-combatants. 
Also, the International Committee of Red Cross (ICRC) has raised some concerns about the use of lasers which may damage eyes permanently. There is another argument against the use of NLWs i.e. they could be used merely to soften up an enemy before killing and many of the weapons could produce/result a painful death if not used correctly. But these counter arguments are really relevant to the use of NLWs in a traditional war. They will most likely be used for peacekeeping missions where they will reduce fatalities by greatly increasing the options for the peacekeeping agencies.
In fact, NLWs have existed since the inception of armed conflicts but there has been an explosion of interest in them during last 25 years. Until recently, almost all information was regarded as classified and only little information was in public domain. R&D on a range of NLWs has since been undertaken internationally by governments as well as weapons manufacturers to fill the gap/need for such weapons. Almost every advanced country has begun to explore the integration of NLWs in their Armed Forces and many have elaborate programmes to develop NLWs and the operational concepts to use them. Also research is in progress for more effective and inexpensive NLWs.
The US is the most advanced country in the world in terms of NLWs. Research in the area of calming agents/drugs continues in the US. Also focus appears on specific sedatives with predictable effects such as opioids like fentanyl (C22H28N2O) & its derivatives, a-adrenergic agonists such as medetomidine (C13H16N2) & its derivatives. Other countries conducting research on NLWs include Russia, France, Germany, Italy, Israel, India, UK & China. The Israel & UK are also conducting joint research with the US.
In Indian context, NLWs are a relatively new phenomenon and traditionally, water cannons and tear gas grenades are commonly used for crowd control, riot control or to prevent movement on a particular position. Sometimes, plastic bullets manufactured by Ammunition Factory, Kirkee, Pune are used by Indian Police in place of conventional bullets for controlling violent mobs.
Oleoresin is available in India and its use may be exploited along with other conventional ingredients of smoke formulations in order to improve their performance for this purpose. In India, Tear Smoke Unit, Takanpur, Gwalior is very active in this area and is manufacturing stun grenades, Rakshak and allied products on a regular basis. There was a plan, discussions and subsequent meetings during 2000-2001 in order to initiate a programme on NLWs {gel bullets, foul-smelling chemicals such as butyl mercaptan (to clear buildings & other closed areas), chemical markers (to identify troublemakers), pulsed chemical lasers (to make targets non-functional), sticky foams (to incapacitate people & vehicles), and disorienting lights, sounds etc} in various defence R&D laboratories. Expertise exists in various DRDO laboratories for the development of NLWs. However, it appears that DRDO did not pursue this programme further.
Acknowledgements: I wish to thank Dr Seema Kakade (Associate Director), N T Agawane, Janardan and Suverna of High Energy Materials Research Laboratory (HEMRL), Pune, for their support in the preparation of this article.
About the Author:
Dr J P Agrawal, former Chartered Chemist & Fellow of Royal Society of Chemistry (UK) and former Director of Materials at Defence Research & Development Organisation (DRDO), has a background of brilliant academic career and valuable professional experience. Dr Agrawal has published more than 165 research papers, technical reports and popular articles in various national and international journals. Also, he has 3 patents and 12 designs to his credit. For details, contact on email:

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