On a Differential Law of War by Gabriella Blum

[Gabriella Blum, an Associate Professor of Law at Harvard Law School, describes her recently published article On a Differential Law of War]

Should the United States, as the strongest military power in the world, be bound by stricter humanitarian constraints than its weaker adversaries? Would holding the U.S. to higher standards than the Taliban, Iraqi insurgents, or the North Korean army yield overall greater humanitarian welfare or be otherwise justified on the basis of international justice theories? Or would it simply be another attempt at tying American hands, a form of “lawfare”?

The paper offers an analytical framework through which to examine these questions. It begins from the observation that the current system of international humanitarian law (IHL) builds on the principle of the equal application of the law—the uniform and generic treatment of all belligerents on the battlefield according to the same rules and principles, and regardless of any disparity in power.. Yet regulation has taken a different path in some other areas of international law—most notably, international environmental law (IEL) and international trade law (ITL)—by linking obligations with respective capabilities. This linkage has been accomplished in several ways: by defining obligations with reference to resources, exempting weaker parties from compliance with certain obligations altogether, and even ordering more powerful parties to extend material assistance to weaker ones. As a group, these types of unequal obligations have been called “Common-but-Differentiated Responsibilities” (CDRs).

The justifications offered for CDRs in environmental and trade law have generally taken one (or more) of four forms: welfare maximization (or utilitarianism), distributive justice, corrective justice, and Samaritanism. The utilitarian justification posits that CDRs are merited if they tend to maximize the stated goal of the regime at hand—often, collective benefit to the participants. The second rationale, distributive justice, seeks to reallocate resources in an equitable way. Meanwhile, corrective justice arguments rest on the idea that those who have contributed to causing harm must make amends to those who have suffered from it. The fourth justification, Samaritanism, assumes that aid is due when one party is uniquely positioned to assist another.

The paper borrows the justifications offered for CDRs in the spheres of international environmental and trade law and tests their possible transposition onto the sphere of war. The inquiry centers on the question of whether a departure from the equal application principle is warranted on the basis of disparities in power and capabilities—on whether a stronger and wealthier country should, as a rule, be held to stricter humanitarian standards than its adversary.

Rather than offering a definitive answer, the inquiry illuminates the types of judgments and predictions that one must hold in order to have a normative position on the question. Most notably, one must consider the degree to which weaker adversaries will be prone to abusing further constraints on stronger enemies, the expected effects of CDRs on the propensity to go to war, who on the enemy’s side is the “enemy,” and what are the duties that are owed to one’s enemies.

In a broader sense, the paper also inquires into the possibilities and limits of analogies from other spheres of international law to the context of IHL. Should war be equated with any other phenomenon for purposes of lawmaking and adjudication? The analysis suggests ways of thinking about war as a phenomenon either unique to or commensurate with other types of national and international relations and demonstrates the ways in which war is at once different from and similar to other fields subject to international regulation.