How the Rules of War Work

War Soldiers with Guns and Gas Masks
While not all nations play by the same rules, their are rules of war most follow. Frank Rossoto Stocktrek / Getty Images

­In the context of any armed conflict, the topic of war crimes inevitably arises, especially in repor­ts of civilian and military casualties and the taking of prisoners of war. The idea of a "war crime" seems to be pretty redundant: Most of us are familiar with the phrase "All is fair in love and war," and in an armed conflict, in which the killing of enemy troops is considered an acceptable means to an end, it may seem that the concept of a "crime" is out of place. But there are countless treaties that declare otherwise, signed by almost every nation in the world.

­The Hague laws and Geneva Conventions are some of the most widely applied of these international agreements. These treaties address, among other issues, the participants of war, the victims of war, occupation by hostile forces and the status of cultural property. In the 2003 war in Iraq, Iraqi troops waved a white flag and then opened fire on the U.S. soldiers who approached to accept their surrender; this act is prohibited under the Hague laws. In World War II, the Nazis in Germany performed medical experiments on civilians; this act is prohibited in all of the Geneva Conventions.


In this article, you will learn about the basic "rules of war" and about specific acts that have been designated as war crimes by the Hague and Geneva Conventions.


There have always been laws of war. Individual armies have their own laws that determine how their military actions will proceed, what is off limits and what is allowed, and "rules of engagement" that dictate the way they initiate battle. Throughout history, opposing nations have established ground rules for war, but until the nineteenth century, these rules applied only to a particular conflict and the countries it involved. Once that war was over, the rules were discarded.

With the 1864 Geneva Convention, the rules of war became an international matter. The laws that came out of Geneva and The Hague transcend any specific conflict. They attempt to "diminish the severity and disasters of war" (Hague IX) in general, applying to armed conflicts across the board.


The Geneva Conventions

Made official in 1949 and ultimately adopted by 190 countries, the Geneva Conventions establish the rules for the treatment of the "victims" of war -- wounded or sick soldiers, prisoners of war, and civilians.

The Geneva Conventions as we now know them were established in 1949, after World War II. But the first Geneva Convention was actually held in 1864. That first conference established a set of rules to protect wounded and sick troops on the field.

The initial 1864 treaty was initiated by an organization called the International Committee for Relief to the Wounded. This organization is now called the International Committee of the Red Cross. The Red Cross was originally established to provide medical care to those wounded in battle. It was created by Henry Dunant, who was traveling through Italy after the 1859 Battle of Solferino and saw dying soldiers left untreated. He asked civilians to help him gather and treat the wounded and insisted they not discriminate based on nationality. The Red Cross was founded on the belief that all soldiers, regardless of which army they belong to, should receive medical treatment.

That first treaty was amended and built upon in subsequent meetings, culminating in 1949 when nations gathered to address the horrors of WWII. The 1949 assembly resulted in the adoption of four Geneva Conventions:

I. Convention for the Amelioration of the Condition of the Wounded and Sick in Armed Forces in the Field

II. Convention for the Amelioration of the Condition of Wounded, Sick and Shipwrecked Members of Armed Forces at Sea

III. Convention Relative to the Treatment of Prisoners of War

IV. Convention Relative to the Protection of Civilian Persons in Time of War

The Hague Conventions

Conferences regarding the international rules of war were held in The Hague, the Netherlands, in 1899, 1907 and 1954. Dubbed the International Peace Conferences, these meetings produced numerous rules, or conventions, that loosely fall into the categories of combat, weaponry, property rights and the duties of neutral countries.

The first two Hague conventions, the 1899 Hague Peace Convention and the 1907 Hague Convention on Land Warfare, are largely similar, the latter expanding and adding to the initial Hague sections on combat laws, illegal weaponry and financial concerns. Another conference was scheduled and then cancelled with the outbreak of World War I.

The severe destruction of cultural property -- artwork, literature, artifacts -- that occurred during World Wars I and II revealed holes in the existing laws. In 1954, the Hague Convention for the Protection of Cultural Property in the Event of Armed Conflict was signed into effect. This third set of laws addressed the issue of cultural preservation in greater depth than the first two, attempting to protect a nation's identity in the face of war and occupation.

As technology and awareness have progressed, the conventions produced in The Hague and those coming out of Geneva have progressively overlapped: Technological developments in the realm of war tend to threaten humanitarian concerns, and humanitarian concerns tend to want to stem the progress of weapons and methods of destruction. These major treaties comprise some of the most essential laws of war, attempting to protect humanitarian, cultural and financial concerns within a framework that inherently wants to disregard everything but the battle at hand.

In the Field

USAF Airman serving as a Chaplain Service Support Personnel: During wartime, his primary responsibility is to provide security for the Chaplain due to laws in the Geneva Convention that make it necessary for religious and medical personnel to be unarmed.
Photo courtesy U.S. Dept. of Defense

The Hague Conventions address not only armed conflict; the very first Hague law stresses peaceful settlement of disputes, going to great lengths to prevent war through very specific procedures intended to reach a diplomatic solution to any national and/or international disagreement. Arbitration, Committees of Inquiry, neutral mediators and what can be described as a 30-day "time out" are all called upon in order to avoid war. It is only once all of these steps have been exhausted that it is acceptable to declare war. And then, a formal declaration -- or an ultimatum indicating a formal declaration -- is necessary. An initial surprise attack is illegal.

Combat and Weaponry

The right of belligerents to adopt means of injuring the enemy is not unlimited. (Hague IV)


Many of the laws governing battle are fairly obvious: It is illegal to misuse a white flag, a symbol of surrender or truce (Hague IV); it is illegal to kill or injure a person who has surrendered; it is illegal to attack a defenseless person or place; it is illegal to attack a building that is being used as a hospital. Some of the rules, however, are less patent.

National and cultural symbols are protected. Armed forces may not use the enemy's flag, uniform or insignia, nor the symbol of the Red Cross, for their own purposes. The enemy's property is not to be taken or destroyed unless it's critical to military operations. Structures dedicated to art, science and charitable missions, as well as any historic or cultural objects, are off limits, unless, of course, they are being used for military operations. In that case, they're pretty much fair game.

In general, there is a ban on weapons whose purpose is to maximize pain and suffering: no poisoned weapons; no bullets that do additional damage once inside the body; no chemical or biological weapons.

Chemical and biological warfare is addressed by both the Hague and Geneva laws. Declaration II of The Hague Peace Conference made deadly gas attacks illegal back in 1899. The 1925 Geneva Protocol prohibited lethal gas and bacterial methods of warfare. The Geneva Convention of 1972 reiterated this prohibition by outlawing the "development, production and stockpiling" of these weapons and insisting on the elimination of any already in existence.

Genocide -- the systematic destruction of a particular group of people based on nationality or ethnicity -- is prohibited by a 1948 treaty dedicated solely to its prevention and the punishment of those who commit it.

Wounded or Sick Troops

In essence: If they're wounded or sick, HELP THEM! The first Geneva Convention addresses the issue of injured or otherwise debilitated troops (as well as medical personnel and chaplains), and takes the humanitarian stance that as soon as a soldier is no longer able to fight, that person ceases to be a target. And beyond that, there is a call to action: Regardless of which side the wounded individual was fighting for, medical attention must be given. This includes actively administering treatment and allowing the Red Cross to administer treatment.

In the blanket protection of wounded or sick troops, medical personnel and chaplains, there is the assumption that these people are unarmed (or, in the case of troops, not able to use whatever arms they may have on them). In the case of medical personnel and chaplains, this raises the interesting paradox that these people are not actually prohibited from bearing arms in order to protect themselves; but if they do arm themselves, they give up certain aspects of their protected status. So in order to be fully protected from attack under the laws of war, they must be vulnerable to attack.

Sick or wounded troops must "in all circumstances be treated humanely, without any adverse distinction founded on race, colour, religion or faith, sex, birth or wealth, or any other similar criteria" (Geneva I). It is illegal to kill, mutilate, torture or perform "biological experiments" on a wounded or sick person. It is illegal to treat this person in a "humiliating and degrading" manner. It is illegal to hold this person hostage.

The Geneva Convention on the treatment of the wounded and sick discusses in detail the way to handle one of the most common aspects of war: death. The dead are to be collected, examined (only to be sure that the person is in fact dead), identified and properly buried. If necessary, fighting must be suspended in order for the dead to be recovered. The bodies must be treated with respect, and, if possible, buried according to their respective religions. Those who die in wartime have to receive the same treatment as those who die in peacetime. Communicating through a Graves Registration Service established at the onset of war, the location of the graves must be provided to the opposing force so that the bodies may be later exhumed and sent home, and all of the property found on the body must be returned to the next of kin.

Prisoners of War

Prisoners are entitled in all circumstances to respect for their persons and their honour. (Geneva III)

First off, prisoners of war are prisoners of the country that captures them; they are not prisoners of the soldier, unit, or commander of the unit that captures them. Also, much along the lines of "innocent until proven guilty," any captured combatant is assumed to be a prisoner of war and must be treated accordingly; if there is any doubt as to the applicability of POW status, the rules regarding prisoners of war must be followed until a proper tribunal is convened to determine whether POW status is applicable on a case-by-case basis. When the United States systematically denied POW status to captured Taliban combatants in the 2001-2002 war in Afghanistan, it was in violation of the third Geneva Convention. In the course of an armed conflict involving parties to the Geneva Convention, captured combatants are POWs until proven otherwise.


Like the sick or wounded, prisoners of war (POWs) are protected under the Hague and Geneva laws from any violence, indignity, or biological experimentation. POWs must receive medical treatment if they need it, and medical staff must be brought in to the POW camp at least once a month to make sure everyone is okay. Unlike the sick or wounded, however, the military hierarchy is observed when it comes to prisoners of war: Officers can't be assigned to the same paid labor as enlisted troops; and while hard labor may be assigned to an enlisted troop as disciplinary action, an officer can't be punished in that manner.

Most of us have seen in movies and on TV the interrogation response of "name, rank and serial number." This stems from the third Geneva Convention, but its purpose is not exactly what it seems. It's true that prisoners of war have to provide their name, rank and serial number (as well as date of birth), but this is not only for identification purposes. It is also to assure that the person be treated "according to his rank or status." If an officer fails to make known that he is an officer, he can't be granted the privileges due an officer.

On the topic of questioning POWs, the interrogation tactics that seem to be common practice in a time of war are all illegal. The third Geneva Convention outlaws everything beyond the simple asking of a question:

No physical or mental torture, nor any other form of coercion, may be inflicted on prisoners of war to secure from them information of any kind whatever. Prisoners of war who refuse to answer may not be threatened, insulted, or exposed to any unpleasant or disadvantageous treatment of any kind.

Confinement is illegal (POWs can't be held in prison cells unless it is for their own protection), but internment is allowed -- they may be kept within certain boundaries. However, their location must be as far from the fighting as possible. Besides being held in a special "camp," prisoners of war are supposed to be granted all of the rights and privileges that their captor grants to its own armed forces, at least in terms of food, water, shelter, clothing, exercise, correspondence, religious practice and other basic human needs. They are supposed to be informed of their exact location -- supplied with their mailing address, in fact -- so that their relatives may send them letters and packages.

Beyond the protection from violence, intimidation and affronts to personal dignity, prisoners of war are supposed to be safeguarded from "public curiosity" (Geneva III). The broadcasting of pictures and video of wounded prisoners of war is an affront to their dignity and an appeal to public curiosity, and as such is prohibited.

Once captured by the enemy, prisoners of war are subject to the laws of the armed force that is holding them. They must act according to the rules and regulations of their captors, and breaking those rules leaves them open to the same trial and punishment as that faced by a member of the detaining military. They are under the control of the detaining power and their detention is legal; as such, their escape is a breach of that law. So if they escape, they can be punished. But only if they are recaptured before they make it make to their own army. If they successfully escape -- if they return to the territory of their own armed forces -- and then are captured once again, they cannot be punished for their previous escape. This same rule of success negating the offense applies to spies who escape their captors: If a spy breaks free and is caught before he makes it "home," he can still be tried as a spy; if he makes it back to his own side and is then recaptured, he is no longer considered a spy who is subject to trial and punishment -- he is considered a prisoner of war, and is therefore protected.

Civilians and Occupation

On the most basic level, civilians are protected by the same general humanitarian principles that govern the treatment of POWs, the wounded, and others not taking an active role in the conflict. Any form of physical violence or degradation is prohibited. An armed force may not attack civilians, nor use them as a "human shield" to render a location protected from attack.

The general purpose of the fourth Geneva Convention is to shield civilians, and children in particular, from the effects of war. It provides for "neutralized zones" where fighting is prohibited, and hospital and safety zones for the protection of the sick, the elderly, pregnant women, children under 15 and mothers of children under seven. These zones are supposed to be labeled with a huge Red Cross sign to ensure their protection. Children are supposed to wear identity badges in case they are lost or orphaned. Hospital workers are also supposed to carry special identity cards so that they are never prevented from performing their duties.


Enemy forces are not allowed to seize personal property unless it is being used against them, and in that case, they must return the property or provide compensation at the end of the war. The main exception to this rule occurs in the case of occupation, when all property related to news reporting may be seized, but even then, the occupying force must return the property or pay for it at the end of occupation. Every building or object connected to religion, charity, education, the arts and sciences and history is protected by the laws regarding private property, even when it is state property.

According to Hague law:

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.

In other words, an armed force is considered in charge if it is, in fact, in charge. Once the occupying force can no longer control the territory, it is no longer an occupying force and is once again simply "the enemy." An occupying force has the absolute responsibility of providing for the basic needs of the people under its control, including food, clothing, shelter, medical attention, and the maintenance of law and order. An occupying force cannot just sit by as occupied territories are looted -- in almost all cases, the laws that were in place in the territory before occupation are still in place after occupation. It is only the enforcer that has changed.

An occupying force cannot punish civilians for anything that occurred before occupation, including anything they may have said against the country now in charge.

Even (or especially) in the case of occupation, communication between civilians, in particular between family members, is treated as an basic right. It may be curtailed only if the correspondence is deemed detrimental to the safety of the occupying force, but even then, civilians may communicate using special forms that allow for at least 25 "freely chosen words" (Geneva IV).

Civilians must not be interned or removed to another country unless it is for their own safety or the safety of the state, and only if there is no other alternative. If people are transferred from an occupied territory, it can only be to another country that has signed the Geneva Conventions. In the case of either internment or transfer, it must be temporary, and the occupying force must make all necessary arrangements to keep track of the people, keep families together and return them to their homes at the end of the hostilities. Occupying forces may not import their own citizens into the occupied territory.

It is legal to force civilians to work, but not in a military capacity against their own country and not as slave labor -- they must be paid for their work. If civilians are used to police a work camp, they cannot be forced to physically punish other workers. International organizations like the Red Cross must have access to civilians at all times and must have access to all work camps, internment camps and "assigned residences." An occupying force is not allowed to tattoo civilians as a means of identifying them.

Cultural Property

Cultural property emblem

It is interesting that the rules devised to protect human beings as much as possible from the ravages of war have also seen fit to address the preservation of cultures. The most obvious link between an individual and a culture is that both are irreplaceable. That humanitarian law specifically protects cultural property indicates the essential role of cultural traditions, of history, in the welfare of individuals and of society as a whole:

...damage to cultural property belonging to any people whatsoever means damage to the cultural heritage of all mankind, since each people makes its contribution to the culture of the world... (Hague Convention, 1954)

Personal property is protected throughout the Hague and Geneva Conventions, but cultural property has an entire document dedicated to its welfare. While the protection of cultural property is addressed in the laws of the 1899 and 1907 Hague Peace Conferences, it was deemed necessary to return to the issue after World War II. In the resulting 1954 treaty, the physical objects that symbolize the culture of a people are protected from seizure and destruction much as hospitals and religious buildings are protected in previous conventions. Cultural property includes historical or architectural monuments, works of art and science, archaeological sites, books and manuscripts, and any building that houses or displays any of these cultural pieces, such as a museum or library.


The protection of cultural property is not solely the obligation of the armed forces. In peacetime, the state is supposed to take measures to ensure the safety of these objects in case of an armed conflict. Once a war breaks out, the responsibility for their protection is shared by the state and the military and, if the state is occupied, by the occupying military as well. An armed force, whether of the state or of the occupying power, is not supposed to use any piece of cultural heritage for military purposes, or for any purpose that could possibly expose it to danger.

Much like the use of the Red Cross emblem to identify a hospital, the 1954 Hague Convention established an emblem to signify cultural property (see right). Three of the symbols arranged in a triangle (two above, one below) indicates protected cultural property. One symbol alone identifies a person employed in the protection of cultural property.

Occupying forces must not export cultural property from an occupied territory, and these items are not allowed to be offered or demanded as reparations at the close of a war.

As of April 2002, 103 nations had signed this agreement.

Consequences of Violation

Nuremberg Trials: Defendants Goering, Hess, von Ribbentrop, and Keitel in front row
Photo courtesy National Archives and Records Administration

Before discussing the penalties of violation, we should define to whom these regulations apply. As it turns out, defining the subjects of the rules of war is somewhat difficult.

It is understood that the conventions apply to the armed forces of all nations that have ratified the conventions. But this is not the final word. The Hague documents state that the laws apply "not only to armies, but also to militia and volunteer corps" that:


  • have a person in command
  • have a representative symbol that can be recognized from a distance
  • carry their weaponry in the open
  • follow the laws and customs of war

It is this last condition that makes defining the application of these laws a bit tricky. Within the context of the member states, all official armies and all non-official armies that meet the requirements listed above must adhere to the rules and are protected by the rules; but one of the requirements listed above is adherence to the rules. So it seems that the conventions apply to the forces that follow the conventions.

Both the Hague and Geneva Conventions address the subject of penalization, but neither states specifically the manner in which a violator should be tried and punished. The first Geneva Convention calls on the Contracting Parties to "enact any legislation necessary to provide effective penal sanctions for persons committing, or ordering to be committed," any of the following violations:

...willful killing, torture or inhumane treatment, including biological experiments, willfully causing great suffering or serious injury to body or health, and extensive destruction and appropriation of property, not justified by military necessity and carried out unlawfully and wantonly.

Financial retribution is specifically mentioned in the Hague Conventions, and in both, imprisonment is implied in statements regarding the necessity of a fair trial. It is pretty much left to the accusing nation(s) to declare a violation of international law and set up war crime trials, which is generally accomplished through the United Nations.

The International Court of Justice (also known as the World Court) in The Hague is a standing body that hears international disputes. In May 1999, Yugoslavia submitted a suit to the World Court alleging that NATO's bombing of the country "amounted to illegal aggression and genocide." The Court ruled against Yugoslavia, declaring that the bombings did not constitute genocide (International Court of Justice Ruling). The Court ruled in February 2002 that a Belgian court was not allowed to try Congolese foreign minister Yerodia Ndombasi for war crimes because he had diplomatic immunity in that country (Crimes of War Project).

Following World War II, an International Military Tribunal was established to try Nazi war criminals. The United States, France, Russia and Great Britain were the prosecuting nations in the Nuremberg Trials, and there were 22 defendants -- one who was missing and presumed dead -- charged with violating the laws and customs of war and crimes against humanity.

Three defendants were acquitted, eight were sentenced to prison and eleven were sentence to death. To learn more about the Nuremberg Trials, see Court TV: A Look Back at Nuremberg.

The International Criminal Tribunal for Yugoslavia was set up in 1991 by the U.N. to try leaders of the former Yugoslavia accused of violating International Humanitarian Law. In total, more than 100 people have been indicted for crimes including genocide, crimes against humanity and violating Hague law, including specific charges for rape. Twenty-five of the accused are still at large, and these proceedings are still being conducted. So far, the court has handed down sentences ranging from five to 50 years in prison, to be served in various countries. For more information, see United Nations: ICTY at a Glance.

There is a movement to establish a permanent, centralized International Criminal Court (ICC) to handle violations of International Law. This court would address not only disputes between nations, which is currently handled by the International Court of Justice, but also disputes between individuals. The ICC has been established by the United Nations and the judges have been elected, but it has yet to hear a case. See United Nations: International Criminal Court to learn more.

For more information on the international rules of war, humanitarian law and related topics, including specific war crimes trials, check out the links on the next page.