During the past two decades, the potential use of biological weapons by terrorists has received a great deal of attention, particularly in the United States. The existence of an anthrax bioweapons development campaign by the government of Iraq was revealed during the Persian Gulf War from 1990 to 1991. Then, in the aftermath of the September 11, 2001 terrorist attacks on the World Trade Center buildings in New York City and the Pentagon in Washington, DC., letters containing a powdered form of Bacillus anthracis, the bacteria that causes anthrax, were mailed to government representatives, members of the news media, and others in the United States. The anthrax-laced powder inside the letters was aerosolized (i.e., the spores became airborne) when the letters were opened, and in a few cases were inhaled. The death of a Florida man was the first...