Too often, military and law enforcement authorities have found themselves constrained by inadequate weaponry: the tools available to them, in addressing confrontations with entrenched opponents of various sorts, are either too weak (not sufficing to disarm or defeat the enemy) or too strong (generating unacceptable collateral damage in harming innocent people or property). An emerging category of non-lethal weapons carries promise for resolving this dilemma, proffering deft new capabilities for disabling, dissuading, or defeating opponents without inflicting death or permanent injury. Some primitive non-lethal weapons (such as truncheons, tear gas, and water cannon) have long been staples in the inventories of police and military forces...