Ryan Goodman on The Power to Kill or Capture Enemy Combatants

During wartime a critical legal question involves the scope of authority to choose whether to kill or capture enemy combatants. An important view, expressed by many contemporary experts, maintains that a combatant can be subject to lethal force wherever the person is found—unless and until the individual offers to surrender.  I argue that, in certain well-specified and narrow circumstances, the use of force should instead be governed by a least-restrictive-means (LRM) analysis. That is, I contend that the modern law of armed conflict (LOAC) supports the following maxim: if enemy combatants can be put out of action by capturing them, they should not be injured; if they can be put out of action by injury, they should not be killed; and if they can be put out of action by light injury, grave injury should be avoided.  Admittedly, there are all manner of caveats and conditions that will qualify the application of this maxim. However, the general formula—and its key components—should be understood to have a solid foundation in the structure, rules and practices of modern warfare. Whether the use of violence against combatants is governed by such constraints has important consequences. One of the most direct implications involves the rules of engagement for forces across the globe—including military powers such as Israel, Russia, and the United States.  As U.S. Major Richard S. Taylor recently wrote, the issue of whether there are rules that require capturing instead of killing unlawful combatants “is a highly relevant—and contentious—question for today’s military commanders and lawyers” and has the potential to alter important practices of western-led coalition partners.   Another implication involves the type of factors that military and civilian authorities would be entitled to consider if states have unfettered discretion to kill enemy combatants during combat. For example, could decisionmakers choose to kill rather than try to capture an adversary based on factors such as the diplomatic fallout from potentially having to hold the individual in custody?  Indeed, would a state be permitted to adopt a strategy that in effect prefers trying to kill rather than capture enemy combatants because detention options are constrained by domestic politics? Note that these questions arise even if there is no direct military advantage in choosing to kill rather than capture.  Indeed, a theoretical question that helps get to the heart of the matter is whether belligerents can decide to kill rather than capture—even when the attempt to capture would not pose a greater risk to their own soldiers’ lives. The significance of this issue has also recently been brought to light by the U.S. Department of Justice White Paper on the Lawfulness of a Lethal Operation Directed Against a U.S. Citizen.  First, the White Paper states that—as a matter of constitutional law—the lawfulness of the use of lethal force in a foreign country against a U.S. citizen who is a senior member of Al Qaeda turns, in part, on whether “the operation would be conducted in a manner consistent with applicable law of war principles.”  Second, the government suggests that—independent of the constitutional question—Congress has passed legislation making it a federal crime to kill an enemy fighter who is a U.S. citizen outside of the United States if that action violates LOAC.  Third, the government acknowledges that if aspects of U.S. kill or capture operations violate LOAC, those executive actions would presumably not be allowed by Congress’s Authorization to Use Military Force. Another important implication of the broader topic—and what is at stake—is the reputation and institutional legitimacy of the International Committee of the Red Cross (ICRC).  In 2009, the ICRC adopted a position favoring an LRM approach in the use of force against legitimate military targets.  The statement by the ICRC was part of a report—Interpretive Guidance on the Notion of Direct Participation in Hostilities under International Humanitarian Law—which the organization issued after a several-year-long study involving military experts around the world.  The principal focus of the consultative process and final publication involved questions concerning when civilians who are involved in hostilities and members of the military forces of nonstate actors can be considered lawful targets subject to military attack. To the reported surprise of many of the study’s expert advisors, the ICRC added a section at the end of the Interpretive Guidance concerning the restraints on the use of force (RUF). In that section, the ICRC declared its support for the following proposition: “The kind and degree of force which is permissible against persons not entitled to protection against direct attack must not exceed what is actually necessary to accomplish a legitimate military purpose in the prevailing circumstances.”  And, the ICRC invoked the “famous statement” of a former President of the organization, Jean Pictet, who had written, “‘if we can put a soldier out of action by capturing him we should not wound him, if we can obtain the same result by wounding him, we must not kill him, if there are two means to achieve the same military advantage we must choose the one which causes the lesser evil.’” The ICRC’s analysis has been criticized severely by a growing number of international law experts, including current and former military legal advisors, across the world.  The section of the Guidance on RUF has quickly become the most controversial aspect of the report.  And, no other significant academic writing has risen to support this part of the Guidance—with the exception of Nilz Melzer the principal author of the report.  The mildest criticisms have concluded that RUF lack support in international law and practice.  Other criticisms have been more reproachful. In an academic analysis of the report, the head of the U.S. Naval War College’s International Law Department states, “The claim that an individual who has not surrendered must, when feasible, be captured (or at least not attacked) is purely an invention of the Interpretive Guidance.”  A leading law of war expert U.S. Colonel Hays Parks—in an article subtitled “No Mandate, No Expertise, and Legally Incorrect”—asserts that the Interpretive Guidance’s “ill-constructed theory is flawed beyond repair.”  Writing in The Army Lawyer, U.S. Major Richard Taylor argues that “the ICRC effectively created the requirement,” and he concludes that “the ICRC has lost sight of its role as trusted advisor and has assumed the position of international legislator.” . . . In this article, I discuss important evidence that has been overlooked and, in some cases, mischaracterized by commentary on RUF. In particular, critics contend that the notion of RUF was the product of a leading but lone expert—Jean Pictet—in the 1970s whose idea was flatly rejected at the time and “lay moribund for almost four decades” until the ICRC attempted to resurrect it in 2009. The critics’ account is at best a serious oversimplification, and at worst involves misattributions and a disregard for other sources of authority on the subject.  That said, most all of these same sources are also overlooked by the ICRC’s study. And, indeed, the Interpretive Guidance eschews the legal foundation that I argue for here. Through original research, this article recovers a history that has been lost in contemporary debates. In particular, I present and analyze voluminous support by international authorities that contradicts the critics’ narrative and largely supports the same end point reached by the Interpretive Guidance. The full record that I foreground thus sheds significant light on the proper interpretation of key legal instruments such as Additional Protocol I to the Geneva Conventions.  This analysis shows how RUF fits into the overall structure of LOAC. And it shows how a parallel set of rules—on the definition of hors de combat—achieves many of the same effects as RUF.  In the final analysis, RUF—and the least restrictive means approach in particular—fit well within the law of modern warfare. In certain circumstances, belligerents must comply with an important (albeit conditional) set of constraints in planning and conducting kill or capture operations against enemy fighters.