Author:Adams, R. Scott
  1. INTRODUCTION II. THE PRINCIPLE OF PROPORTIONALITY A. Express Law . B. Historical Background C. Interpretation of the Proportionality Principle D. The Delicate Problem III. PROPORTIONALITY IN THE TARGETING PROCESS A. Collateral Damage Estimation Methodology B. Commanders C. Decision Vulnerability IV. THE POWER PARADOX A. Physiological Effects of Power B. Psychological Effects C. Exceptions and Weaknesses V. EMPATHY A. Empathy and the Law B. Empathy and Operations C. Mitigating the Empathy Deficit D. Legal Advisor's Role VI. CONCLUSION O, it is excellent To have a giant's strength, but it is tyrannous To use it like a giant (1) I. INTRODUCTION

    Military lawyers provide regular instruction to members of the U.S. military on the subject of international humanitarian law (IHL). (2) This instruction generally focuses on broad principles of IHL: Military necessity, humanity, proportionality, distinction, and honor. (3) In this context, proportionality is often described, almost poetically, as the principle that creates balance and harmony between the competing concepts of necessity and humanity. (4) However, a codified rule of proportionality did not appear in IHL treaties before the first Protocol Additional to the Geneva Conventions (AP 1) of 1977, a treaty the U.S. has never ratified. (5) Yet, notwithstanding the relatively recent appearance of the rule, it is beyond question that proportionality, as a limitation on attacks, has quickly and convincingly become binding customary international law. (6)

    The principle of proportionality holds that attacks are prohibited if they are expected to cause excessive incidental harm in relation to the concrete and military advantage anticipated. (7) This restriction on attacks is perhaps the most curious of all IHL principles, and more academic writing has focused on proportionality than any other principle. (8) The curiosity arises primarily from its ambiguity and resulting discretion that is given to commanders. The law can only be found at the extremes. (9) Proportionality prohibits those attacks which are clearly excessive. (10) It does not prohibit those that are clearly not excessive. (11) All potential attacks between these two extremes are subject to a vague balancing test that tells commanders to weigh incommensurable and dissimilar interests. (12) As a result, commanders have a burdensome amount of discretion and very little guidance. They cannot use mathematical equations. There is no chart to reference. Commanders are forced to rely on intuition in assessing the proportionality of an attack. (13)

    Recent scholarship has sought to consider this proportionality assessment in light of social science, particularly cognitive biases and heuristics. (14) This work has generally sought to draw attention to weaknesses and vulnerabilities in lethal decision making, while simultaneously calling for more research on the subject. (15) In reading such works, one senses a rising tide of scholarship intended to inform the decision-making process commanders undertake when considering an attack. This article seeks to contribute to that work by identifying another potential obstacle to assessing whether incidental harm is excessive. Specifically, a growing body of research suggests that an individual's power may have substantial effects on, among other things, risk tolerance and capacity for empathy. (16)

    Most practitioners will be quick to point out that, in practice, commanders more often wrestle with questions of factual certainty than proportionality. The rule of proportionality prohibits excessive civilian casualties that are expected by the reasonably well-informed person, making reasonable use of the information available. (17) Commanders often consider attacks knowing that uncertainty surrounds the possibility of civilian harm. Attacks with expected civilian harm are far less common. Nonetheless, in an asymmetrical conflict, expected civilian harm occasionally arises during the targeting process. In such cases, the commander's staff at the targeting cell presents information on the target and the value it presents to operations; (18) they show the collateral damage estimate, which approximates, among other things, expected civilian deaths; (19) the lawyer then repeats what the commander already knows, "The attack cannot cause excessive civilian harm in relation to the anticipated military advantage;" (20) The room falls silent as the commander quietly makes a final decision.

    This article will summarize the elusive principle of proportionality, and the effect of power on that principle. Because the law leaves commanders to wrestle with ambiguity, this article is focused less on what the law requires and more on the ethics of applying the law. The term ethics is used here to describe the branch of knowledge that deals with moral principles. (21) More simply, it is "doing the right thing," as explained by former Secretary of Defense James Mattis. (22) The primary purpose of this article is to identify an obstacle to finding that "right thing" in proportionality tests. After identifying that obstacle, this article will conclude with several ideas on how to overcome it, with an emphasis on the role of the legal advisor.


    1. Express Law

      The principle of proportionality is codified in Articles 51 (5)(b) and 57(2)(b) of AP l. (23) Article 51(5)(b) states an attack is indiscriminate and prohibited if it "may be expected to cause incidental loss of civilian life, injury to civilians, damage to civilian objects, or a combination thereof, which would be excessive in relation to the concrete and direct military advantage anticipated." (24) This provision of AP 1 was identified by the International Committee for the Red Cross (ICRC) as a critical component of the Protocol, and the ICRC referred to it as a "key article." (25) Similarly, Article 57(2)(b) states, "an attack shall be cancelled or suspended if it becomes apparent that ... the attack may be expected to cause incidental loss of civilian life, injury to civilians, damage to civilian objects, or a combination thereof, which would be excessive in relation to the concrete and direct military advantage anticipated." (26) The United States has publicly expressed its view that these provisions are customary international law. (27)

      Although Articles 51(5)(b) and 57(2)(b) are almost universally referred to as the rule or principle of proportionality, they do not contain the word "proportionality." This is not an accident or a matter of semantics. (28) Rather, during Diplomatic Conferences related to AP 1, many States worried that the word "proportionality" implied an equilibrium exists between incidental harm and military advantage. (29) Many states wished to avoid implying that any sort of precise measurement or optimum decision calculus was possible, and thus adopted the language present in AP 1. (30) Nonetheless, "proportion" is the most intuitive word to describe the rule. The Department of Defense (DoD) Law of War Manual thus describes proportionality by stating the rule "weighs the justification for acting against the expected harms to determine whether the latter are disproportionate in comparison to the former." (31)

    2. Historical Background

      As previously explained, this rule of proportionality in IHL treaty law is an invention of the 1970s, (32) though commanders may have contemplated the principle for intuitive or practical reasons long before. During the American Civil War, the code of conduct applicable to Union soldiers was known as the Lieber Code. (33) The Lieber Code mentions incidental harm, but only with permissive language: "Military necessity admits of all direct destruction of life on armed enemies, and of other persons whose destruction is incidentally unavoidable." (34) Operating under the Lieber Code, General William Sherman explained that his attack of Atlanta was justified by military necessity. (35) Sherman implicitly argued that the incidental harm was proportionate, (36) and that the responsibility for proportionality was with the defending, rather than the attacking force. This argument continues to be embraced by some critics of AP 1, (37)

      The modern practitioner, who no longer focuses on the enemy's responsibility for proportionality, must wonder at whether Truman would have paused before Hiroshima, had a lawyer confronted him with today's proportionality test. When reflecting on his decision just over one year later, (38) Truman wrote that he had "no qualms about it whatever," (39) and that he had not lost a wink of sleep over the decision. (40) The moral philosopher Michael Walzer points out that this is not the sort of statement we expect from leaders. (41) We want them to bear the burdens of painful decisions. (42) Truman at least objected to a film's portrayal of him making a snap judgement on the issue. (43) But, with the notable exception of Eisenhower, subsequent Presidents have, at least implicitly, agreed that the decisions to drop the atomic bombs on Hiroshima and Nagasaki were the correct ones. (44) This surprising unanimity raises questions about the limiting effect of proportionality in practice. (45)

      More modern examples show proportionality is an accepted restraint, but applying it remains challenging. For instance, during Israel's 2006 conflict with Hezbollah, Israel targeted and killed two Hezbollah combatants, but incidentally killed four civilians. (46) Based purely on the numbers, killing four civilians alongside only two combatants seems disproportionate. Yet, even the non-government organization Human Rights Watch found this attack unobjectionable under the circumstances. (47) In another more recent example, the Trial Chamber of the International Criminal Tribunal for the Former Yugoslavia (ICTY) attempted to establish a specific standard for proportionality tests. (48) The Trial Chamber ruled in Prosecutor v. Gotovina that attacks...

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