What Does International Law Have to Say About Nuclear Weapons? And What Does This Have to Say About International Law?

In 1996, the International Court of Justice—the judicial arm of the United Nations—was asked to advise on whether the "threat or use" of nuclear weapons "in any circumstances" was or was not consistent with international law. The Court responded that there is no legal prohibition against such weapons per se, but that numerous principles of widely-subscribed treaties and of customary law imposed severe restrictions on both the threat and the deployment of nuclear devices. These limitations, as a practical matter, declare that in nearly any foreseeable circumstances, nuclear weapons may not be used. This outcome was disappointing to many observers, who felt that the Court had missed an opportunity to make an affirmative case for disarmament. But the Court's task in this instance was not to state what it wished the law to be: the Court was required to state no more and no less than what the law actually is. In so doing, the International Court of Justice provided lessons regarding not only jus in bello—the law of war—but also the role of international law as applied to such significant and critical issues.