However, this challenge is usually of limited scope, with political objectives confined to such conventional goals as assuming power in a state or gaining independence. Their violence, however disruptive, still accepts the state-based international order as an organizing principle. One might even claim that by aspiring to eventually become recognized state authorities, most terrorist groups reaffirm and strengthen an international order that is based on states. The challenge posed by the Islamic State and al-Qaeda is different. These groups have many more state enemies than most terrorist groups, and they challenge the practical sovereignty of their target states in more...