There is debate in the weapons of mass destruction and bioterrorism literature over whether the threat from smallpox is exaggerated or realistic; however, there has been insufficient evaluation of the factors that indicate whether the threat is valid or overblown. Insufficient weight has been given to whether there are groups or individuals who are capable or have demonstrated the intent to use smallpox as a weapon, which should be key factors in evaluating the level of threat posed by the virus. To address the issue of the gap in the specific risk assessment of a smallpox attack, the following issues will be considered: (1) capability whether smallpox is a realistic agent for terrorists to use; (2) motivation what types of terrorists might pursue smallpox as a bioweapon; and (3) deterrence whether current U.S. and international policies are likely to impact this decision.