Why We Fight Matters to How We Fight
We have all been taught that jus in bello (the law regarding the conduct of war) is a distinct set of rules from jus ad bellum (law regarding resort to force). It is a convenient distinction for many purposes. It is particularly convenient for military lawyers, who are often asked to advise officers on how to fight but rarely to advise presidents on whether to fight.
Still, this distinction is simplistic and often a barrier to serious thinking. These categories cannot be entirely separated.
A Brief History
One reason for thinking so is that philosophers, jurists, and commanders have been writing about restraints on armed conflict for many centuries. But the Latin phrases we now use for these categories were only coined by an Austrian law professor in the 1930s and then popularized by the International Committee of the Red Cross (ICRC) (which is eager to instruct the world on jus in bello norms but, as a “neutral umpire,” is very keen to avoid judgments on ad bellum justifications). New terms had to be devised because no such terms (or analogs) were used in earlier times, even by writers who wrote whole treatises in Latin.
Emer de Vattel’s mid-18th Century treatise, the main guide to international law for the American founders, endorsed “devastation” (wholesale destruction of agriculture and buildings) to deal with the most dangerous enemies, though seeing it as otherwise deplorable. Later writers endorsed similar exceptions. Nothing like the modern terms appears in the treatise of international law by Henry Halleck (who commissioned and edited Lieber’s Code) nor in Oppenheim’s treatise (the leading English-language treatise on the eve of the First World War), nor in their foreign counterparts.
Even today, people have it in the back of their minds that the kind of war makes a difference to the kind of weapons that could reasonably be used. In the mid-1990s, the International Court of Justice (ICJ) was asked to provide an advisory opinion on whether use of nuclear weapons could ever be lawful, given the inevitable destructiveness of such weapons. The Court’s answer was hardly ever . . . but (said a narrow majority of the Court) perhaps when national existence is at stake. So nuclear States maintain their stockpiles, though over many decades and through many wars they have not dared to use such weapons.
That is not just a view that defers to popular opinion. Michael Walzer, a particularly earnest moralist on such questions, argued in his Just and Unjust Wars that it was wrong for Britain (and the United States) to bomb German cities in the Second World War, given the predictable scale of civilian suffering caused by this tactic. But even Walzer allowed that Royal Air Force raids on German cities were, after all, justifiable in the extreme circumstances of 1940-41, when an isolated Britain was fighting for its survival, and the fate of civilization seemed to hang on the outcome. Walzer did not suggest that extreme circumstances excused violation of all rules but rather that the rules should be applied with a “sliding scale” (his term). Claims for defense in extremity (the ad bellum consideration) could justify a more permissive approach to the normal rules of restraint (under jus in bello). It mattered, in Walzer’s view, not only how close Britain was to actual defeat but what kind of enemy it was fighting and therefore what the consequence of defeat might mean.
Present Instruments and Practice
Even legal documents reflect some background recognition that differing contexts call for differing rules. The contemporary law of armed conflict (LOAC) treaty structure is built on assumptions about the relation between ad bellum and in bello rules, though slightly disguised under somewhat more formal categories. The ICRC originally proposed a single set of rules for all conflicts, but the Geneva diplomatic conferences of the mid-1970s quickly decided that “non-international conflicts” should have different rules. Additional Protocol II (AP II) ended up much shorter and more permissive. There is no “proportionality” rule in AP II and no provision for prisoner of war (POW) protections. The underlying assumption seems to be that a sovereign State has special claims to suppress a force trying to displace the national government or divide the nation.
Meanwhile, Additional Protocol I (AP I) begins by embracing (within the “international conflicts” covered by its more restrictive rules) “armed conflicts in which peoples are fighting against colonial domination and alien occupation and against racist régimes in the exercise of their right of self-determination . . . .” Fighters in these wars deserve protections not available to ordinary rebels against an ordinary government. By the same logic, the racist or colonial government must accept restraints that would not apply to defending States in an ordinary civil war.
These provisions certainly reflected self-serving rhetoric that was prevalent among communist and developing States in the 1970s (where wars they favored were always depicted as wars of “national liberation,” as with North Vietnam’s conquest of its neighbor). But most of the world has ratified these treaties and accepted the implicit distinctions they make between kinds of war. Similarly, AP I Article 54 prohibits destruction of foodstuffs and other resources required to sustain the civilian population—a “scorched earth” policy—but makes an exception when implemented as means of defense against an invader.
By telling contrast, the most frequently invoked provision in AP I, the so-called “proportionality” requirement, is blind to such contextual distinctions. Article 51(5)(b) prohibits “attacks” which “may be expected” to cause harm to civilians or “civilian objects” which “would be excessive in relation to the concrete and direct military advantage anticipated.” This formulation seems to take for granted that “military advantage” is something that can be assessed independently of the purposes for which the armed conflict is pursued. But the determination to continue fighting, like the initial decision to resort to force, is driven by political considerations, as much as assessments of military capacity.
The drafters of AP I were surely aware of this reality. They went to considerable trouble to provide POW protection for guerrilla fighters who did not identify themselves as combatants before battle. When a force is too weak to fight in the open (what Art. 44(3) AP I vaguely calls “the nature of hostilities” in such circumstances), it is very unlikely to secure decisive “military advantage” against a more fully equipped and better trained regular army. The aim of guerrilla warfare in most situations is not to disable the opposing force but to undermine its morale, and still more to undermine the commitment of the political authorities deploying that army.
It is not only in irregular conflict, however, that political commitment is tested. It is a recurring dimension of war. That means the side with more to lose may (reasonably) exert more force not only to constrain the opposing force but to signal its determination. Fair-minded observers reasonably take this into account. Tactics that might seem excessive in relation to a limited war for limited aims may seem more acceptable in an all-out war, where allowing the enemy to continue fighting risks terrible harm to one’s own civilian population.
To take the most familiar recent example, the ferocity of Israel’s Gaza invasion reflects the ferocity of the Hamas invasion of Israel that provoked it. The scale and sadism of the initial Hamas atrocities showed that Israel was threatened by an enemy which would do the worst it was capable of doing to Israeli civilians and then boasted of its intention to re-enact such bloodbaths. It requires willful blindness to context not to acknowledge that Israel was justified in risking more harm to Palestinian civilians in its war against Hamas, given that the risks to Israel were so much greater than those posed by ordinary, low-grade terrorism (where victims would be counted in single digits rather than thousands).
The same reasoning applies to Ukraine’s defense against Russian aggression. If the initial Russian incursion had been very constrained, merely adding a few more villages to the border region already under Russian control, it would seem reasonable to regard Ukrainian missile strikes into Russian territory as recklessly provocative, and any resulting civilian casualties as “excessive” in AP I terms. After all, Ukraine was never likely to incapacitate the entire Russian army (let alone, the additional forces that Moscow might mobilize over time). But Ukraine’s NATO sponsors have become more patient with more aggressive Ukrainian tactics, as signals of Ukraine’s commitment to continue in what has become a long, fierce war, placing Ukraine’s very survival at risk. Which tactics are reasonable, which are morally acceptable, depends on the kind of conflict involved, which usually turns on what the fight is about.
The instinctive response of military lawyers is that if we allow rules to be adjusted for a good cause, both sides will claim the exemption in every war and then there will be no rules left to regulate the conduct of war. This objection does, of course, point to a real and serious challenge. But it is far from an irresistible counter-argument against letting ad bellum realities affect our view of applicable in bello standards.
To begin with, we should remind ourselves that central standards of jus in bello are already quite hard to apply, even when viewed in isolation. The U.S. Department of Defense and the ICRC have quite different interpretations of the proportionality rule (prohibiting incidental harm to civilians that is “excessive”). In practice, observers tend to divide on concrete military measures as they do in their general view of the war. The standard may still be worth remembering but it is (as most military lawyers acknowledge) very hard to apply. That is probably why no international criminal tribunal has yet dared to rest a prosecution on violation of this standard.
There remains a larger point. Few military conflicts, and even fewer particular battle campaigns, are adjudicated by a reputable tribunal with authority to punish violators. By and large, the sanction for LOAC violations is moral opprobrium. And when it comes to doling out this sanction, anyone can participate and most participants are both partisan (with regard to the side they favor in the conflict) and poorly informed (at least on the details of the combat situation). So we are already dealing with a “law” that has a very high ratio of moralistic rhetoric to on-the-record lawyering. To say we need to preserve artificially clear rules for evaluating military tactics is like saying we need to bring a well-functioning umbrella before venturing into a hurricane. The relevant rain gear for these public debates are arguments that acknowledge the force of circumstances.
Concluding Thoughts
I do not mean to set out an entire alternate approach to LOAC. Some rules may reasonably be regarded as absolute, since they do great harm to the reputation of the perpetrators and do little to assure military success. Hugo Grotius was open to enslavement as a possible sanction in war but balked at rape (as did Spanish apologists for early modern conquistadors who readily accepted many other brutal tactics). We may hold it an absolute rule today that POWs should not be subject to torture, certainly not to physical mutilation.
But these are not the rules that give rise to serious dispute. When it comes to judging the appropriateness of tactics that cause incidental harm to civilians (or civilian objects), a morally responsible assessment must give some consideration to what is at stake in the conflict. If a tactic helps assure a speedier victory, that must matter, especially if a prolonged war will entail more civilian suffering. If military defeat will risk great harm to core security concerns, risking great loss of life on the attacker’s side, that must matter. It may not be worth arguing whether we call such considerations “defenses” or “extenuations” but to exclude them altogether risks reducing the most morally serious inquiry to a game of “gotcha.”
Before his appointment to the ICJ, Professor Hersch Lauterpacht described LOAC as operating at the “vanishing point,” that is, the outer margin, of international law. It is precisely at that margin that the analyst must keep the larger moral context in mind. The law of war should help guide and constrain serious moral judgment about war. We do not have a law of war for the convenience of military lawyers.
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Photo credit: U.S. Army, Sgt. 1st Class Nicolas A. Cloward
