Biological warfare is one leg of the triad of weapons of mass destruction (coupled with nuclear and chemical weapons). Biological weapons pose a significant threat to the United States military and public population across the spectrum of conflict. There is, however, little common knowledge of the insidious yet devastating potential of these weapons. This paper is written for the lay (that is non-technical) reader, outlining the history, threat, and possible countermeasures related to biological warfare agents. The intent is to heighten the awareness level regarding biological warfare as a military and terrorist threat.