In considering strategies for terrorism countermeasures, a simple typology of terrorism provides a basic teaching tool and suggests directions for research. Terrorism aimed at civilian personnel has spawned studies of the ecology of terrorism and terrorist groups. Studies of their history, psychology, and strategy have provided a basis for codified procedures for dealing with the incident and for neutralizing its effect on the real victims -- fear in a target population. Military terrorism involving professionally trained soldiers and guerillas who use terrorist activities to retain or seize a regime's power is another aspect of insurgency-counterinsurgency terrorist theory of interest to military security studies. Both civilian and military terrorism spill over into conventional terrorism. Such terrorism is a form of war against the few by a few in the midst of many. In this area, intelligence is critical for saving lives (counterterrorism) or taking them (terrorism). Nuclear terrorism and its appalling potential has spawned studies of incidents of attempted sabotage and of nuclear devices and weapons. Because much of this information is highly classified, its study is particularly appropriate for those at war colleges.