The intentional use of biological or chemical agents to cause disease or destroy food and water supplies for political or economic reasons dates to antiquity. The turn of the twentieth century heralded the development of lethal biological and chemical weapons capable of mass destruction. By the final two decades of the twentieth century, individuals and small groups learned how to obtain and use these weapons effectively. The events of the past few decades, including the World Trade Center and anthrax attacks in 2001, have shown that small groups of individuals, as well as nations, have the...