ChatGPT launched in November 2022, triggering a global debate on the use of artificial intelligence (AI). A debate on AI-enabled lethal autonomous weapon systems (LAWS) has been underway far longer. Two sides have emerged: one in favor and one opposed to an international law ban on LAWS. This essay explains the position of advocates of a ban without attempting to persuade opponents. Supporters of a ban believe LAWS are already unlawful and immoral to use without the need of a new (...) treaty or protocol. They nevertheless seek an express prohibition to educate and publicize the threats these weapons pose. Foremost among their concerns is the “black box” problem. Programmers cannot know what a computer operating a weapons system empowered with AI will “learn” from the algorithm they use. They cannot know at the time of deployment if the system will comply with the prohibition on the use of force or the human right to life that applies in both war and peace. Even if they could, mechanized killing affronts human dignity. Ban supporters have long known that “AI models are not safe and no one knows how to reliably make them safe” or morally acceptable in taking human life. (shrink)

International law evolved to end and prevent armed conflict as much as for any other reason. Yet, the law against war appears weaker today than ever in its long history, evidenced by raging armed conflicts in which people are killed, injured, and forcibly displaced. The environment is devastated, and the planet impoverished. These consequences can be traced to the dominant ideology of realism. In 1946, Hersch Lauterpacht challenged that ideology by contrasting it with the idea of international law, composed of (...) natural law, positive law, and process theory. The Art of Law in the International Community revives his vision, rebuilding the understanding of why international law binds, what its norms require, and how courts are the ideal substitutes for war. The secret to the renewal of international law lies in revitalizing the moral foundation of natural law through drawing on aesthetic philosophy and the arts. (shrink)

The international law regulating resort to armed force, still known by the Latin phrase, the jus ad bellum, forms a principal substantive subfield of international law, along with human rights law, international environmental law, and international economic law. Among theologians, philosophers, and political scientists, just war theory is a major topic of study. Nevertheless, only a minority of scholars and practitioners know both jus ad bellum and just war theory well. Lack of knowledge has led to the erroneous view that (...) the two areas are in conflict. This article responds to this misapprehension, explaining the deep compatibility of international law and just war theory. Today's jus ad bellum, especially the peremptory norm against aggression, is not only the law; it also forms the minimum threshold of a just war under just war theory. In other words, for a war to be morally just, it must at least be lawful. To go to war in violation of the jus ad bellum is both a legal and a moral wrong. Compliance not only fulfills the general moral good of obedience to law; it forms the first step toward fulfilling moral obligations in the grave area of war. This characterization of the relationship between law and morality is seen in the history of the legal prohibition on force and in the actual set of rules that make up the contemporary regime. Comprehensive and persuasive accounts of the jus ad bellum and just war theory consistently reflect this thesis. (shrink)