The article documents that terrorism is a serious threat to Western democracies including the United States as well as an international threat. The conclusion of the article is that it has become more difficult to counter terrorism due to technological advances which have delivered greater destructive power into the hands of a few fanatics. The primary technological effects discussed are (1) those relating to communication which has enabled terrorists to establish a 'world-wide network' and (2) the addition of toxins and nuclear weapons to the arsenal of the terrorist. As an international problem, however, the difficulty of countering terrorism is not rooted in the technological sophistication of the terrorist but in international disputes about the question, 'what is terrorism.' Nations appear to be unable to mount an international assault against terrorism due to the difficulty of arriving at a commonly accepted definition of terrorism. This article discusses the obstacles to defining terrorism encountered by the international community and the role that bilateral and multinational agreements have played in countering terrorism. (Publisher abstract)