The report discusses terrorist motivation to carry out weapons of mass destruction (WMD) attacks, ease/difficulty of obtaining WMD capabilities, the possible magnitude and consequence of terrorist WMD attacks, and terrorist groups of interest. The paper claims that terrorists most likely to attempt attacks with weapons of mass destruction are extremist religious millenarian groups and small splinter terrorist cells. The ability of terrorists to produce or obtain WMD may be growing as a result of looser control of stockpiles and technology in the former Soviet Union and the dissemination of technology and information. However, WMD are difficult to produce or obtain and are probably beyond the reach of most terrorist groups. Two groups that combined the motivation to use WMD with substantial resources are the Japanese sect Aum Shinrikyo and Usama Bin Ladin's organization, Al-Quiada. The paper concludes that the Aum, now under close national and international scrutiny, are unlikely to repeat their earlier efforts (a Sarin gas attack in the Tokyo subway), and there is no strong open source evidence that Bin Ladin or his organization have acquired WMD. Notes