Terrorism refers to the use of illegitimate means for political-ideological purposes.1 With respect to its means, terrorism typically involves violent tactics aimed at civilians on a relatively massive scale, much like in the case of war. Yet, terrorism is different from warfare in that it exists outside, and purposely operates against, the principles of war as they are regulated in the international community of nations. Acts of terrorism are politically oriented and ideologically motivated, ranging from specific goals formulated in terms of the might of political nation-states to more general aims related to the plight of certain peoples and groups. Because of the political-ideological objectives of terrorism, the underlying ideas of terrorism are important to consider as the motivating forces that fuel terrorist groups and individuals. Strategically, the instilling of fear is an important immediate objective of terrorism.