Islam is a law-governed religious faith that proscribes and prescribes human conduct. The jihad—the religious prescription to struggle and strive in the path/way of Allah until Allah's word reigns supreme throughout the earth—including its military sense, is despite disavowal in popular piety and much modern moderate Islamic discourse, a binding religious prescription. This presumption of an enduring obligation to wage the military jihad is an essential starting-point in potentially delegitimizing al-Qaeda's reign of terror among adherents for whom shari'a compliance is an essential requirement.Recent important jurisprudential debates among jihad-realist Islamist militants have produced several conclusions that may be used to delegitimize al-Qaeda's terror as both unlawful and imprudent. The majority of those conclusions arise from recent decades of "prison debates" in Muslim-majority societies over the legality, methods, means, and pragmatics of violent rebellion against their own governments.These rulings are supplemented by others of vital relevance for undermining al-Qaeda terrorism directed principally against noncombatant civilians living in Muslim-minority societies. Among the latter, the most decisive legal rulings include the following: (1) murder is one of the gravest and forbidden of sins; (2) the impermissibility of targeting Muslims, and non-Muslim civilians, especially women, children, the elderly, scholars, and students of knowledge; (3) the impermissible extension of the principle of Tartarrus, or human shields; (4) the impermissibility of treachery, violation of oaths, and pacts of security granted (implicitly, or explicitly) to Muslims in non-Muslim majority societies; (5) jihad is impermissible unless specific capacities, conditions, and circumstances are present; (6) permissibility to wage offensive jihad must be granted by parents and creditors; (7) impermissibility of violating a voluntary oath of unconditional allegiance and obedience (bay'at) given to one's recognized ruler; (8) the impermissibility of waging offensive jihad under present conditions of Muslim weakness vis-a-vis the infidel powers; (9) the permissibility of jihad, emigration, or a truce when facing infidel occupation; (10) the impermissibility of attacking American civilians of an occupying country in the name of jihad or under its banner; and, (11) the imprudence of al-Qaeda based and inspired terrorism.