Human experience with nuclear, biological, and chemical (NBC) warfare has been limited, especially in comparison to conventional forms of warfare. Our experience with nuclear warfare is confined to a period of less than one week during the end of World War II, when the United States successfully used two nuclear weapons against targets in Japan. The course of biological warfare and modern use of biological weapons are difficult to track owing to the difficulty of differentiating deliberate use from natural outbreaks. However, the keen potential of biological weapons in acts of terror was...