The U.S. Armed Forces don't do much shooting anymore. Even in Afghanistan, they engage in more advising and guiding than gunplay. Soldiers today are asked more often to keep the peace or defuse demonstrations, and the last thing they want in those situations is to fire a lethal weapon. That's why the Pentagon is spending more and more research-and-development dollars on weapons that stun, scare, entangle or nauseate--anything but kill.
The U.S.'s nonlethal-weapons programs are drawing their own fire, mostly from human-rights activists who contend that the technologies being developed will be deployed to suppress dissent and that they defy international...