Necessity in International Law

Necessity is a notoriously dangerous and slippery concept-dangerous because it contemplates virtually unrestrained killing in warfare and slippery when used in conflicting ways in different areas of international law. Jens David Ohlin and Larry May untangle these confusing strands and perform a descriptive mapping of the ways that necessity operates in legal and philosophical arguments in jus ad bellum, jus in bello, human rights, and criminal law. Although the term "necessity" is ever-present in discussions regarding the law and ethics of killing, its meaning changes subtly depending on the context. It is sometimes an exception, at other times a constraint on government action, and most frequently a broad license in war that countenances the wholesale killing of enemy soldiers in battle. Is this legal status quo in war morally acceptable? Ohlin and May offer a normative and philosophical critique of international law's prevailing notion of jus in bello necessity and suggest ways that killing in warfare could be made more humane-not just against civilians but soldiers as well. Along the way, the authors apply their analysis to modern asymmetric conflicts with non-state actors and the military techniques most likely to be used against them. Presenting a rich tapestry of arguments from both contemporary and historical Just War theory, Necessity in International Law is the first full-length study of necessity as a legal and philosophical concept in international affairs.

Jens David Ohlin is Professor of Law and Associate Dean for Academic Affairs at Cornell Law School. He specializes in international law and criminal law. He specifically focuses on the laws of war with special emphasis on the effects of new technology on the waging of warfare, including unmanned drones in the strategy of targeted killings, cyber-warfare, and the role of non-state actors in armed conflicts. He authored The Assault on International Law (Oxford, 2015). Larry May is the W. Alton Jones Professor of Philosophy, Professor of Law, and Professor of Political Science at Vanderbilt University. He has published over thirty books, including book length studies of each of the four crimes under the ICC's jurisdiction. These books have won awards in philosophy, law, and international relations. He has also published extensively on the history of the just war tradition, especially on the work of Grotius and Hobbes. He co-authored Proportionality in International Law (with Michael Newton, Oxford, 2014), and Limiting Leviathan: Hobbes on Law and International Affairs (Oxford, 2013).