This article examines the nature of religious terrorism, principally with reference to al-Qaeda. It argues that a distinction must be made between the ultimate aims and the immediate objectives of 'religious' terrorists, and that while the ultimate aims will be religiously formulated, the immediate objectives will often be found to be almost purely political. This distinction is illustrated with reference to such premodern religious terrorists as the Assassins and Zealots. Immediate objectives, are for many purposes more important than ultimate aims. Although the immediate objectives of al-Qaeda on 9/11 cannot be established with certainty, it is highly probably that the intention was to provoke a response from the US that would have a radicalizing impact on al-Qaeda's constituency. Reference to public opinion in the Middle East, especially in Egypt, shows that this is indeed what has happened. Such an impact is a purely political objective, familiar to historians of terrorism from at least the time of Errico Malatesta and the 'propaganda of the deed' in the 1870s. While no direct link between Malatesta and al-Qaeda exists, al-Qaeda was certainly in contact with contemporary theories that Malatesta would have recognized, and seems to have applied them. Even though its immediate objectives are political rather than religious, al-Qaeda is a distinctively Islamic group. Not only is its chosen constituency a confessional one, but al-Qaeda also uses - and when necessary adapts - well-known Islamic religious concepts to motivate its operatives, ranging from conceptions of duty to conceptions of ascetic devotion. This is demonstrated with reference to the Last Night' document of 9/11. The conclusion is that terrorism which can he understood in political terms is susceptible to political remedies.