You may read Jihad and the Modern Word, part 2 of 2, in this month’s Ascent Magazine, the magazine published by the Harvard and MIT Students on Islam and Society.
B. Jihad in the Classical Juristic Tradition
Turning to the post-Prophetic era, classical jurists unanimously divided jihad into two main modalities. The first we may refer to as “aggressive jihad,” which is pro-active, and according to the majority, constituted a communal requirement to be carried out at least once every year. The second modality was the “defensive jihad,” which was waged whenever Muslim lands were attacked. This jihad was actually a much more serious affair than its counterpart, inasmuch as many of the stipulations and restrictions governing aggressive jihad were dropped in the case of defensive jihad. For example, the Muslim ruler did not have to announce the obligation to join the defensive jihad nor conscript soldiers for its prosecution. Similarly, all those groups who were normally exempt from participating in the aggressive jihad, e.g., women, minors, the elderly, young men who had not been granted permission by their parents, were required to participate in defensive jihad. For our purpose of trying to determine the credibility of the claim that Islam is a religion of peace, we may ignore the defensive jihad. For no one would accuse Islam, or any other religion for that matter, of not being a peaceful religion simply because it insisted on defending itself. We shall thus restrict the remainder of our discussion to the aggressive jihad.
Part 1 is also available.