War is governance: explaining the logic of the laws of war from a principal-agent perspective.

• Date: 01 June 2014
• Author: Benvenisti, Eyal

What is the purpose of the international law on armed conflict, and why would opponents bent on destroying each other's capabilities commit to and obey rules designed to limit their choice of targets, weapons, and tactics? Traditionally, answers to this question have been offered on the one hand by moralists who regard the law as being inspired by morality and on the other by realists who explain this branch of law on the basis of reciprocity. Neither side's answers withstand close scrutiny. In this Article, we develop an alternative explanation that is based on the principal-agent model of domestic governance. We pry open the black box of "the state" and examine the complex interaction between the civilian and military apparatuses seething beneath the veil of sovereignty. Our point of departure is that military conflicts raise significant intrastate conflicts of interest that result from the delegation of authority to engage in combat: between civil society and elected officials, between elected officials and military commanders, and within the military chain of command. We submit that the most effective way to reduce domestic agency costs prevalent in war is by relying on external resources to monitor and discipline the agents. Even though it may be costly, and reciprocity is not assured, principals who worry that agency slack may harm them or their nation's interests are likely to prefer that international norms regulate warfare. The Article expounds the theory and uses it to explain the evolution of the law and its specific doctrines, and it outlines the normative implications of this new understanding of the purpose of the law. Ultimately, our analysis suggests that as a practical matter, international law enhances the ability of states to amass huge armies because it lowers the costs of controlling them. Therefore, although at times compliance with the law may prove costly in the short run, in the long run states with massive armies are its greatest beneficiaries.

TABLE OF CONTENTS INTRODUCTION I. A PRINCIPAL-AGENT THEORY OF IHL A. A Potential Conflict of Interest Between Principals and Agents During Warfare B. Inadequate Domestic Mechanisms for Controlling the Agents C. IHL as an Optimal Response to Principal-Agent Problems 1. Third Parties as Fire Alarms 2. IHL as a Credible Threat Against Agents 3. IHL as Legal Handcuffs D. The Relationships Between Morality, Reciprocity, and Governance as Motivations for IHL II. TESTING THE HYPOTHESES: TRACING THE ORIGINS OF MODERN IHL A. An Intensifying Conflict of Interest Between Principals and Agents B. The Need to Move Away from Unilateral Constraints C. The Internationalization of Governance D. The Limits of IHL as a Mechanism of Governance 1. IHL and Naval Warfare 2. The Law on Neutrality 3. The Law on Internal Armed Conflict III. SPECIFIC NORMS AND INSTITUTIONS A. Norms 1. Regulating Access to the Battlefield: The Privilege to Participate in Hostilities 2. The Status of Prisoners of War 3. The Prohibition on Taking Booty 4. The Prohibition on the Use of Certain Weapons and Types of Ammunition 5. The Law of Occupation B. Institutions 1. Information-Generating Institutions 2. "Military Necessity" 3. Reprisals IV. ASYMMETRIC WARFARE AND PRINCIPAL-AGENT RELATIONS: WHAT ROLE FOR IHL? A. Operational Legal Advisers B. Domestic Review by Independent Actors C. The Rise of International Criminal Law V. Normative Implications CONCLUSION INTRODUCTION

Intuitively, the laws of international armed conflict (hereinafter "IHL") are meant to regulate interstate action. As such, their very existence is puzzling: Why would opponents bent on destroying each other's capabilities commit to and obey rules designed to limit their choice of targets, weapons, and tactics?

Traditionally, two kinds of answers have been provided to this question. On the one hand, moralists regard IHL as being inspired by morality. (1) On the other, realists explain the evolution of the law on utilitarian grounds and view compliance with it as a product of the threat of reciprocal retaliation. (2) We contend that both answers address only part of the dynamics of warfare and are therefore only partially convincing. Morality was obviously an important factor in the promotion of IHL, especially by nonstate actors. But it is difficult to reconcile morality with a law that strictly relies on state consent and is based on state practice, often reflecting not the aspiration to strive for just war during battle but rather the primacy of military necessity. (3) Nor can morality explain the codification process of IHL, which was dominated by military experts and governmental officials keen on promoting national interests. (4)

The prevailing "retaliatory" explanation of IHL makes more intuitive sense at first blush. The tit-for-tat scenario can be modeled as an indefinitely iterated prisoner's dilemma and illustrated by real-life examples, such as the trench warfare of World War I (5) or specific stories concerning the treatment of prisoners of war ("POWs") during the two World Wars. (6) But this explanation, too, does not withstand close scrutiny as the main explanation for IHL's continued efficacy. To be effective, reciprocity requires that each side have ample information confirming the opponent's intention and ability to comply with the law indefinitely. This condition is rarely met during combat. The noise of the battlefield typically induces adversaries to interpret their enemy's mistakes as intentional violations of the law and prompts them to retaliate in kind. More seriously, the shadow of the future is often quite narrow. For combatants actually involved in combat, each battle may well be their last; for their commanders, it may be crucial to eventual victory. This is especially true during the closing phase of a war: the losing side, with its back to the wall, cannot be expected to obey laws that guarantee its defeat; and the winning side, on the cusp of victory, is unlikely to worry about reprisals for its own breaches of the law. (7) With such an anticipated endgame, cooperation based on an iterated prisoner's dilemma situation will quickly unravel.

Moreover, the retaliatory tit-for-tat explanation misses many aspects of the dynamics of war that reflect coordination games such as chicken or battle of the sexes rather than prisoner's dilemma. The prisoner's dilemma story cannot explain the codification process of IHL during the second half of the nineteenth century, which was characterized by pressure emanating from the stronger European nations to clarify the law, in particular the law of occupation. (8) As in the classic battle of the sexes game, the weaker countries were far less eager to accept a law that would benefit their more powerful enemies, but they preferred some law that would constrain any future invader or occupier rather than no law. (9) As this Article will explain, other wartime situations reflect the chicken game, where some parties have a dominant preference to abide by IHL regardless of their opponent's choice. (10) In these scenarios, IHL serves as an effective tool to promote parties' self-interest. In the Article, we argue that this self-interest, which is independent of the opponent's attitude toward compliance, is what explains the evolution and nature of IHL. This self-interest was met by the weaker states' gratitude for being granted some protection against evil rather than no protection.

While we do not reject the two traditional explanations for IHL as additional layers of explanation for some IHL rules and for the observance of IHL in some armed conflicts, we think that neither of them can account for the drive to codify, modify, and further develop IHL since the mid-nineteenth century, nor can they explain its continued viability. We submit that these two explanations fail to grasp a crucial factor in the dynamics of modern warfare: the need for each side to control its own forces. The leaderships of contending armies may indeed be motivated by moral concerns or locked in a reciprocal relationship, but this is not why they rely on IHL; for this they need no formal law, just as the princes and kings in earlier times could rely on their shared understandings about the law. Modern militaries and their civilian leaderships need IHL--indeed, a kind of IHL that is specifically tailored to control the agents--because they collectively face a daunting challenge of controlling their respective troops, whose interests may diverge from their own. During war each decisionmaker has a different future to consider: the state's president will have a long-term vision, contemplating the transition to peace, while the army commander will focus more concretely on the grand picture of the war. But the foot soldier at the service of them both has a rather concrete future to consider--how to be effective and survive the current assault on enemy positions. The need for law to maintain discipline within the fighting forces rises in direct relation to the growing disparity between the different "futures" that shape each actor's preferences.

In the Article, we explain why a codified, specifically designed IHL is necessary for resolving hierarchical governance challenges more than horizontal relations between armies. We believe that this intricate internal dimension of warfare, which traditional accounts of IHL largely miss and scholars of international law often disregard, provides an important key to an understanding of IHL's development and resilience since the mid-nineteenth century. This Article looks beyond the veil of sovereignty and examines the interplay between the various domestic actors whose interests are implicated by war. Our rationale is informed by the observation that states engaged in armed conflict are not unitary actors but rather complex institutions that include internal chains of command within the echelons of power, accountable to a civilian government and...