The general class of nonlethal weapons includes a wide variety of technologies:
• Kinetic weapons are decidedly low-tech—bean-bag rounds for shotguns and rubber bullets for pistols have been used for a long time.
• Barriers and entanglements can be used to stop land vehicles moving at high speed (such as a car trying to speed through a checkpoint) or to damage propellers of waterborne craft.
• Optical weapons (e.g., dazzling lasers) are used to temporarily blind an individual using bright light—the individual must shut or avert his eyes to avoid pain. Such weapons are often used on individuals operating a vehicle, with the intent of forcing the driver to stop or flee.
• Acoustic weapons project intense sound waves in the direction of a target from long distances, and individuals within effective range feel pain from the loud sound.
• Directed-energy weapons that project millimeter-wave radiation can cause a very painful burning sensation on human skin without actually damaging the skin.32 Such weapons, used to direct energy into a large area, are believed to be useful in causing humans to flee an area to avoid that pain. Other directed-energy weapons direct high-powered microwave radiation to disrupt electronics used by adversaries.
• Electrical weapons (e.g., tasers and stun guns) use high-voltage shocks to affect the nervous system of an individual, causing him or her to lose muscle control temporarily. One foundational science for understanding such effects is neuroscience, as discussed in Chapter 2.
• Biological and chemical agents may be aimed at degrading fuel or metal, or may target neurological functions to incapacitate people, repel them (e.g., with a very obnoxious odor), or alter their emotional state (e.g., to calm an angry mob, to induce temporary depression in people). For the latter types of effects, a foundational science for understanding such effects is neuroscience.
• Cyber weapons are often included in the category of “nonlethal” weapons because they have direct effects only on computer code or hardware.
32 Directed-energy weapons with this effect are sometimes regarded as being weapons based on neuroscience, since they manipulate the central nervous system, even if the mechanisms involved are not chemically based. See, for example, Royal Society, Neuroscience, Conflict, and Security, Royal Society, London, UK, February 2012.