This fear is rooted in the belief that a new type of terrorist is posing a new kind of threat; the new terrorist is viewed as motivated to perpetrate mass casualties by using WMD. The specific issues explored in the conference were differences between "old" and "new" forms of terrorism, the future use of WMD portended by the emergence of new terrorist groups and individuals, how the term "terrorism" should be conceived in order to encompass all of the possible non-state uses of WMD, and the improved calibration of the WMD terrorist threat for the future. Conference participants were divided on the central issues. Some participants argued that the obstacles to the acquisition and use of nuclear, chemical, and biological weapons have eroded to such an extent that the use of such weapons in the near future is likely. Others viewed the acquisition and use of such weapons to produce mass deaths and casualties as a complex mix of technical capabilities, motivations, goals, and other factors whose outcome cannot be predicted with any certainty, but which is not generally supported by the historical record. Topics discussed by the seven panels were as follows: what the past can indicate about the future, classic politically motivated non-state terrorist groups, other types of non-state terrorist groups, lone operators and mass casualties, states' use of terror, the impact of technological change, and the calibration of the threat of mass casualties and terrorism changes. Appended conference agenda and participants