A Functional Approach to Targeting and Detention

The international law governing when states may target to kill or preventively detain nonstate actors is in disarray. This Article puts much of the blame on the method that international law uses to answer that question. The method establishes different standards in four regulatory domains: (1) law enforcement, (2) emergency, (3) armed conflict for civilians, and (4) armed conflict for combatants. Because the legal standards vary, so too may substantive outcomes; decisionmakers must select the correct domain before determining whether targeting or detention is lawful. This Article argues that the "domain method" is practically unworkable and theoretically dubious. Practically, the method breeds uncertainty and subverts the discursive process by which international law adapts to new circumstances and holds decisionmakers accountable. Theoretically, it presupposes that the domain choice, rather than shared substantive considerations embedded in the domains, drives legal outcomes. This Article argues, to the contrary, that all targeting and detention law is and ought to be rooted in a common set of core principles. Decisionmakers should look to those principles to assess when states may target or detain nonstate actors. Doing so would address the practical problems of the domain method. It would narrow the uncertainty about when targeting and detention are lawful, lead to a more coherent legal discourse, and equip decisionmakers to develop the law and hold one another accountable.IntroductionThe international law governing when states may target to kill1 or preventively detain2 nonstate actors is in disarray. Much of the blame lies with the method that international law uses to answer that question. The method establishes distinct standards in four regulatory domains: (1) law enforcement, (2) emergency, (3) armed conflict for civilians, and (4) armed conflict for combatants. Because the standards vary, so too may substantive outcomes. Decisionmakers must select the correct domain before determining whether targeting or detention is lawful.That method-which I call the "domain method"-creates two serious problems. One is uncertainty.3 Many modern situations do not fit comfortably in any domain, leading to intractable disputes about which one governs. For example, legal analysts disagreed on whether the U.S. operation targeting Osama bin Laden fell within the combatant or the law enforcement domain. The operation was lawful under one but probably not under the other.4Some uncertainty reflects substantive disagreements and is inevitable, given the decentralized nature of the international legal system. But the domain method inhibits decisionmakers from resolving uncertainties even when they agree on substance. In several contexts, decisionmakers with different policy perspectives have been groping toward similar "hybrids"- outcomes that are more permissive than those associated with one domain but more restrictive than those associated with another. For instance, many decisionmakers seem to appreciate that, when targeting terrorism suspects abroad, states have more authority than in law enforcement settings but less than against combatants.5 Such hybrids are not grounded in any domain, so they cannot effectively be justified using the domain method. The method discredits them in favor of the available but contested extremes. Separately, the method discourages decisionmakers from agreeing on outcomes in one case because of perceived slippery-slope implications for others. For example, the U.S. government and Human Rights Watch agree that the United States may lawfully target certain al-Qaeda suspects in Yemen.6 Instead of embracing that agreement and trying to develop shared parameters for counterterrorism operations, each pushes for its preferred domain. Each seeks to avoid the overly expansive or narrow implications of the alternative.7Breeding uncertainty is troubling in its own right, but it also points to a more serious problem: the domain method stifles legal discourse. …