The changing nature of terrorist attacks in the previous decade has cast doubt on the commonly accepted constraints on terrorist violence. Claims that these constraints are eroding has led to an unstudied assumption that modern terrorist groups, and al-Qaeda in particular, are not subject to constituency constraints. Most alarming is the possibility that al-Qaeda, allegedly unconcerned with alienating supporters, will attack the United States with weapons of mass destruction (WMD). Yet no detailed study of al-Qaeda's constituency constraints has been undertaken, even though they devote considerable effort to win popular support among Muslims. This book reveals that al-Qaeda seeks the support of a constituency as the central pillar of their strategy. This constituency, contrary to Western portrayals, largely does not support indiscriminate killing and would not support a WMD attack. Al-Qaeda is aware of this sentiment, and as a pragmatic group is willing to alter their methods to gain supporters. Consequently, al-Qaeda is not likely to conduct such an attack for fear of alienating this constituency.