Brief Comments on Rules of War

Given the trend in some of the comment threads here, I think it’s worth time to give some brief consideration to the problems at the nexus of law, war, and justice. Modern rules of war are now referred to as the Law of Armed Conflict (LOAC), a term that I sometimes worry clouds the issue as much as it illuminates; “law” necessarily implies the existence of unlawful activity, which means more or less the same thing as “war crime,” which is a concept that everybody likes to use but nobody really likes to define in practice, and that is in any case only rarely prosecutable in any kind of meaningful way. I think that a more abstract approach tends to work better in many cases than a tight focus on the legality or illegality of specific acts during a conflict. Note that LOAC and the body of knowledge that has developed around its conception and execution is enormously rich and complex, and that I won’t here be getting into questions that guide much modern military planning such as proportionality, discrimination, or the doctrine of double effect. And so…

1. There are rules, my dear Walter, in both bowling and in ‘Nam. War is a rule-based activity. This is necessarily true of all wars at all times. A war must involve, on one side at least but almost always on two or more sides, the collective violence of a group of people who have organized themselves according to certain rules of behavior. Every collective that has ever engaged in war, from Bolivian guerrillas to the 10th Mountain to the Fifth Battle Squadron to a Comanche war band to a Viking raider group to a Greek hoplite phalanx to a Roman Legion to an RAF fighter wing has been organized to do violence by a set of rules that regulate behavior and coordinate action. War is the greatest consciously collaborative activity that humans have ever engaged in, and consequently war requires rules. These rules are sometimes (often!) observed in the breach, but as is the case in domestic law the breach does not destroy the rule. People who insist that you must “smell the gangrene” and accept that “anything goes” in war are making spectacularly ahistorical claims that have zero foundation in the millennia of first-person accounts we have of the actual practice of war across a broad spectrum of cultural contexts. The rules of war often include guidelines on appropriate behavior towards the enemy. Sometimes, especially when combatants have repeated interactions with one another, rules of conduct develop between warring parties as well as within them. These rules vary enormously over time and context, and collisions between different sets of rules often result in spectacular brutality. But in a great many cases both parties to a conflict will not only be aware that there are rules that guide conduct towards the other party, but will actively attempt to abide by those rules because of a variety of considerations that include religious commitment, concerns about iteration, practical and principled belief in moderation, etc.
2. To my view the greatest innovation of modern Western Just War Theory (a very old body of thought manifested imperfectly in modern form as LOAC) is the distinction between jus ad bellum and jus in bello. Jus ad bellum is the justice of war, or essentially whether the war your collective has launched fulfills certainly conditions of justice. Jus in bello is justice in war, or whether your behavior as a collective or individual in in accordance with certain conditions of justice. There is a firewall between these two concepts, and that firewall is incredibly important to maintain for both moral and practical reasons. A soldier may perform war crimes (violations of jus in bello) in a just war; a soldier may behave in accordance with the rules of conflict despite fighting in an unjust war. This distinction became particularly important in Middle Christendom as authorities discovered that Christian princes enjoyed fighting one another as much or more than fighting the various heretics who lived to the north, south, and east of Christian Europe, and it became desirable to regulate those wars without excommunicating the participants. It follows that a soldier for the Nazi regime is not a war criminal, regardless of whether he is a hapless conscript, an enthusiastic volunteer who joined up to shoot Frenchmen just like his old man, or an ideologically committed believer in the tenets of National Socialism, unless he violates the rules of war by (for example) intentionally targeting civilians or murdering prisoners of war or whatever else. Similarly, a Belgian soldier fighting in a manifestly just war can commit war crimes by executing German prisoners or torturing German civilians. Unjust war can be fought justly, and just wars can be fought unjustly.
3. This distinction can seem absurd on its face but it serves two practical purposes. First, it gives soldiers fighting in unjust wars (even wars that they themselves deem as unjust but in which they must participate for whatever reason) an incentive to abide by the rules of war. If every Russian soldier in Ukraine believed that he would be prosecuted (and possibly executed) simply for the crime of serving in the Russian Army, these soldiers would be less likely to abide by (often inconvenient) rules that protect Ukrainian civilians, Ukrainian civilian property, and Ukrainian prisoners of war. Second, states (as well as individuals) are only rarely good judges of the justice of their own causes. Most countries believe that the wars they are conducting are manifestly just; this was certainly true of the Axis in World War II, and is more or less true even of Russia today. If participation in a just war gave soldiers free license to violate the jus in bello rules of war, those rules would effectively disappear and the term “war crime” would be completely meaningless as anything other than victor’s justice. The answer to “was My Lai a war crime?” cannot rest upon the answer to the question “was America’s cause in the Vietnam War just?” unless you want every army to abandon every restriction on its behavior towards civilians.

Where does this leave us? You’re free, if you’d like, to declare that the direct targeting of civilians by Hamas on October 7 was Just because of the inherent justice of the Palestinian cause (jus ad bellum implies jus in bello). But if you’re going to make that claim you need to grapple with the full weight of what that claim means. Fighter pilots serving in the Israeli Defense Force also believe their cause to be just, and there is no Global Justice Tribunal capable of adjudicating between these claims. This means embracing an account of justice that is inherently subjective and that consequently will do no good at all with respect to limiting the destructive behavior by soldiers on either side of any conflict. If that’s the world you want, fine, but be clear about it with yourself and everyone else.

There is, to be sure, a “the law, in its majestic equality, forbids Hamas and Israel alike to fire unguided rockets at civilian settlements and behead ravers with shovels” problem to all modern LOAC conversations. Jus in bello restricts attacks to targets of military significance, a restriction that necessarily favors the more militarily powerful party to a conflict. But then LOAC also prohibits the stronger party from exerting the full force of its capability. There are probably reasons why Israel refrains from simply flattening and paving Gaza, civilian casualties be damned, that don’t have anything to do with jus in bello. I can guarantee, though, that jus in bello considerations are part of the conversation that Israeli military and political elites are having with one another and with the US, Europe, and the rest of the world. There are enormous potential costs, thus, in adopting an “anything goes as long as you think Justice is on your side” policy, even for those who consider LOAC to be an overly confining set of rules.

So what does this mean? I have found it enormously troubling that many advocates of Palestine (on X, in comments here, on campus, on Facebook, and wherever else they’ve been in my life) did not bother to wait for Israeli retaliation before exalting the justice of the massacres that Hamas undertook on October 7. In some conversations it has become clear that folks really did not have a good sense of the broader implications of what they were arguing. Thus, this post. There is little question in my mind that Israeli retaliation will soon (if it hasn’t already) exceed the guidelines imposed by LOAC (there is no lawful way of extricating Hamas from Gaza), and that’s a problem but it’s a different and in some ways more “normal” problem than the one posed by open embrace of Hamas’ brutality. The thing about being forced to embrace a gang of murderers like Hamas is that no one outside of Gaza is ever actually forced to embrace a gang of murderers like Hamas; wait a week and there’ll be some genuine Israeli war crimes that you can complain about online.