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Experience April/May 2024

The Laws of War

David Z Kaufman


  • Wars have served to define entire centuries and had the effect of altering the course of human history and national or regional borders in significant ways.
The Laws of War
shironosov via Getty Images

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The laws of war is a bit oxymoronic. War is inherently violent, brutal, and vicious. After all, settling a dispute by overwhelming violence can’t reasonably be expected to be conducted in a civilized manner.

But after humankind’s experiences in two world wars, countries attempted to civilize the uncivil wartime experience. That’s why poison gas and dumdum bullets are outlawed. There are four Geneva Conventions and several treaties that compose the laws of war. But these rules can lead to counterintuitive results, and the laws of war, designed to civilize warfare, frequently have the opposite effect.

These days, especially since October 7, 2023, when Hamas attacked Israel, many people are using words and phrases taken from the laws of war with which they’re likely unfamiliar and are using these technical words colloquially in ways that differ from what the words actually mean.

Sometimes these misuses are deliberate. Sometimes they arise from emotion and sometimes from ignorance. In any case, it’s appropriate to point to the famous aphorism from The Princess Bride: “You keep using that word. I do not think it means what you think it means.”

Because we can’t discuss the laws of war without some understanding of what people are saying, I’ve attempted (with a substantial amount of humility) to compile a list of key words and phrases I’ve encountered, along with the colloquial (mis)uses of the word or phrase, and then the word’s actual meaning.

Obviously, because of space issues, what I’ve written is necessarily incomplete and certainly without nuance. If you’re interested in delving deeper into the meaning of each word or phrase, you can access literally hundreds of law review articles and books about each topic. A good starting point would be the U.S. Department of Defense’s Law of War Manual. Not only will it explain the standards against which the U.S. armed forces measure their conduct, it has literally hundreds of footnotes to additional source material that I’ve found invaluable.

Also, I want to be very clear here since some will likely claim I have biases and prejudices. Those people are probably right. I’m a Jew. I have family living outside Jerusalem. My son-in-law fights in the Israeli Defense Forces, and my grandchildren sleep in concrete safe rooms. I’ve tried to be objective but will concede that I may have failed. So be it.

With all that said, this is but a poor attempt to summarize for the layperson some of the meanings best illustrated by The Princess Bride’s meme.

Jus ad bellum and Jus in belloJus ad bellum is a right to war in Latin and are criteria in which war may be justifiable. Jus in bello is the law of waging war, and it refers to international law and customs regarding what can’t be done by parties at war. In other words, when it’s right to resort to armed force. Jus ad bellum requires that the cause for war is just, that the right authority makes the decision, that the decision is made with the right intention of bringing about peace, that the war is a last resort, and that the overall evil of the war doesn’t outweigh the good.

Jus in bello is the law governing what’s acceptable in using such force. Most of what’s discussed below is jus in bello.

Genocide—The colloquial meaning of this word seems to be killing a lot of people. There appears to be no distinction between combatants and civilians. Usage: “Israel is committing genocide in Gaza.”

The actual definition of genocide is contained in Article II of the Geneva Convention on Genocide, and it requires the intent to destroy, in whole or in part, a national, ethnical, racial, or religious group. Note that the number of dead isn’t part of the definition. Nor is a comparison of casualty counts (more in proportionality, below).

It’s also worth noting that the prohibition against genocide reaches to nonstate actors as well as nation states. Thus, a nonstate actor may commit genocide as well as a state actor. An example is Cambodia and Pol Pot. Also compare the Hamas charter advocating the utter destruction of Jewry with Israel’s stated war aims of retrieving its citizens held hostage and holding Hamas accountable for its actions.

Collective punishment—The colloquial meaning of this phrase seems to be a lot of innocent people are suffering because they have been caught up the fighting. Usage: “Israel is imposing collective punishment on all Gazans.”

But collective punishment is normally defined as penalties, including criminal and administrative punishments or fines, imposed on a group of people for actions committed by someone else. Note that it’s a deliberate policy against innocents rather than the unfortunate fact that the innocents have been caught in the middle of fighting.

Siege—The colloquial meaning of this word seems to be illegally surrounded by armed forces that illegally keep people from supplies and communications, including electricity and water. Usage: “Israel has illegally imposed a siege on Gaza, illegally depriving Gazans of food, medical supplies, electricity, and water.”

But surrounding enemy combatants isn’t illegal. According to the U.S. Law of War Manual, it’s lawful to besiege enemy forces; in other words, to encircle them with a view toward inducing their surrender by cutting them off from reinforcements, supplies, and communications with the outside world.

Note: The conduct of a siege may require the imposition of measures of control to ensure that outsiders may not deliver supplies to enemy forces.

Also note: The besieging force isn’t required to agree to the passage of medical or religious personnel, supplies, and equipment if there are serious reasons for fearing that the consignments may be diverted from their destination, the control may not be effective, or a definite advantage may accrue to the military efforts of the enemy.

According to the U.S. Law of War Manual, evacuation of noncombatants and the wounded from a besieged area is subject to the agreement of the belligerent parties. The commentaries suggest that an evacuation is strongly recommended whenever the military situation allows.

Ethnic cleansing—Colloquially, ethnic cleansing is when a civilian population flees the combat area either voluntarily or at the urging of one of the belligerents. Usage: “Israel is engaging in the crime of ethnic cleansing when it urges Gazans to flee the area of combat to safety.”

Ethnic cleansing isn’t defined under international criminal law, but a good definition can be found on Wikipedia: Ethnic cleansing is the systematic forced removal of ethnic, racial, or religious groups from a given area with the intent of making a region ethnically homogeneous. Methods of achieving this goal may be war crimes, but ethnic cleansing is not.

Apartheid—This is actually a formal system of racial segregation characterized by an authoritarian political culture favoring certain ethnic groups. The crime of apartheid was further defined in 2002 by Article 7 of the Rome Statute of the International Criminal Court as encompassing inhumane acts [acted upon] an identifiable group on political, racial, national, ethnic, cultural, religious, or other grounds “in the context of an institutionalized regime of systematic oppression and domination.”

Many international groups have accused Israel of operating a system of apartheid. But in Israel, there’s an Arab political party with members in the Knesset, the Israeli parliament. There are Supreme Court justices, doctors, and lawyers who are Arab and Palestinian. Israel guarantees all of its citizens the same rights.

So while evidence of a formal system of segregation seems lacking, there does appear to be some evidence that Israeli efforts to enhance its security disfavor Palestinians as a group. As a result, many international organizations have accused Israel of practicing apartheid.

Proportionality—This has several meanings under jus ad bello and jus in bello. In the vernacular, this seems to mean you killed many more of them than they did of you, so your response is disproportionate. Users seem to be copying the infamous body count of the Vietnam War. But the comparative casualty count isn’t the correct metric.

Proportionality under jus ad bello is what’s commonly called the just war theory. In other words, is the war a proportionate response to the provocation? See the discussion of the six factors that must be present to justify a war.

Proportionality under jus in bello, as defined by the International Committee of the Red Cross, requires that the effects of the means and methods of warfare used must not be disproportionate to the military advantage sought. This is confusing to the layperson and frequently relies upon hindsight.

It’s easy to say blowing up an apartment building to kill a simple fighter is disproportionate. But what if the person isn’t a simple fighter but the area commander whose death could result in a quick end to the battle? What if there’s a cache of weapons hidden in a home? Does it depend upon the size of the cache?

These aren’t easy questions, especially when information is concealed in the general fog of war and the decision may be influenced by emotions. Using 20-20 hindsight, a nonpartisan reviewer might easily take serious issue with some decisions. It’s almost always impossible to resolve these questions in real time.

Distinction—Belligerents are expected to distinguish their adherents (soldiers) from the local civilian population. But nonstate armed groups often seek to blend in with the civilian population. At the same time, state armed forces, though obligated to be discriminate, aren’t required to take additional protective measures to compensate for such tactics.

Clearly these principles of distinction can lead to great confusion and civilian casualties. Worse still, nonstate armed groups may seek to use ostensibly civilian buildings and resources to conduct and sustain their operations. Denying nonstate armed groups such support may be particularly important to the success of military operations and justifiable under the law of war.

The principle of distinction prohibits the use of protected persons or objects to shield, favor, or impede military operations. Thus hiding combatants or weapons among civilians or civilian facilities, as is common in the Gaza tunnels, violates the principle of distinction.

Note: The principle of distinction absolutely prohibits the taking of hostages. Similarly, there’s an absolute prohibition to using civilians or other protected persons to shield, favor, or impede military operations.

Rules of engagement—These are the rules under which a war or battle is fought or policed. These are the rules about when a weapon may or may not be used. As such, they vary in time and place.

For example, the ROE when in an active combat area will be different from the ROE when guarding a fortified outpost. As you might expect, there’s always a debate about exactly what ROE are appropriate. A U.S. example: The debate in the United States on police use of force.

Note: The ROE where belligerents are indistinguishable from civilians until the moment of truth are always debated because no choice is risk free.

Occupation—Colloquially, Israel occupies Gaza because Israel controls Gaza’s borders, except for its border with Egypt, and maintains a naval blockade.

But occupation describes a temporary legal status caused by war. The 1907 Hague Convention stipulated that “territory is considered occupied when it is actually placed under the authority of the hostile army. The occupation extends only to the territory where such authority has been established and can be exercised.”

It’s not clear how controlling a nation state’s border with an antagonistic territory is occupying the other territory, especially when one area of the state also borders a third-party nation state.

Civilian—In a noninternational armed conflict, this means all persons who are neither members of state armed forces nor members of an organized armed group.

Note: News reports discuss deaths in Gaza without distinguishing between members of any organized armed group who might be legitimate targets and those who are true civilians. Without that information, it’s impossible to apply the principles of distinction and proportionality, the rules of engagement, and jus in bello.

War crimes—This is often an accusation used by people who disapprove of whatever action is being taken. But these are the actions that, if proven, violate the rules of war:

Targeting civilians in violation of the rules of distinction and proportionality

  • Concealing combatants within protected structures, such as hospitals
  • Failing to distinguish combatants from civilians
  • Taking hostages
  • Refusing Red Cross representatives access to hostages and prisoners
  • Refusing to allow civilians to flee a siege
  • Even if proven, it’s not a violation of war to undress and search prisoners for concealed weapons or to prevent resupply of weaponry of besieged areas.

You’ve surely noticed that most of these words and phrases have much nuance, even when used colloquially. The emotions underlying the verbiage of the laws of war as weapons should, but too often doesn’t, encourage careful consideration of the facts. I hope this small lexicography helps change that.