, and which have thus played a part in creating the international political atmosphere in which terrorism has developed into a major concern. Examples of the first type of work are studies of movements, such as the Zealots in ancient Judea or the Assassins in medieval Islam, that followed tactics suggestive of those of modern terrorists. Examples of the second type of work are discussions of the ideologies of national liberation which have, broadly speaking, provided the framework of justification for both guerilla warfare and terrorism in the modern Third World, as well as for domestic terrorists in the West who have either asserted solidarity with Third World movements or (in the case of right wing terrorists) asserted their opposition to such movements, their ideologies, and their actual or supposed sympathesizers in the West.
Certain works may justifiably be considered as belonging in both of the above categories. For example, the Russian anarchist terrorists of the late nineteenth centuries contributed both to the development of radical leftist ideology, and therefore to the ideological framework of leftist (and, indirectly, of rightist) terrorism, and who also developed the concept of "propaganda by the deed," and therefore introduced an explicit theory of terrorism as a form of communication.
The second broad category, literature on contemporary terrorism and terrorist movements can also be divided into two classes, which may be broadly charactized as descriptive and theoretical; the distinction is relatively marked, although many works combine descriptive and theoretical material to a greater or lesser degree.
The descriptive literature of terrorism ranges from the journalistic to the statistical, and includes works of a scholarly, partisan, and even practical orientation, the latter characterization applying to works that seek to provide instruction either to counter terror specialists or to busin...