The terms “war crimes”, “crimes against humanity” and “genocide”, are often used interchangeably, as if they all referred to the same acts. However, these words have a precise legal definition and different implications and consequences.


“War crimes”, as the term suggests, are crimes committed in connection with an armed conflict, whether international or not.

The term “war crimes” covers a wide range of different acts, including rape and torture that would, if committed in peacetime or in situations of violence falling short of armed conflict, constitute crimes punishable under national laws.

“War crimes” are thus violations of the laws and customs of war. However, not all violations of the laws of war are “war crimes”.

Violations of the laws and customs of war qualify as “war crimes” only if they are sufficiently “serious”, that is, involve death, injury, destruction or unlawful taking of property, or if they breach important values, even without physically endangering persons or objects directly.

War crimes include, for example, abusing dead bodies, subjecting persons to humiliating treatment, making persons undertake work that directly helps the military operations of the enemy, violations of the right to fair trial, using and recruiting children under 15 years of age to participate in armed conflicts, and starving civilians.

For example, while stealing a piece of bread from villagers does not respect their private property, the consequences will very likely not be sufficiently serious for this act to qualify as a war crime. To the contrary, bombing the village bakery with the intention of starving the civilian population qualifies as a war crime.

In addition, a number of violations of the Geneva Conventions of 1949 and of Additional Protocol I of 1977, which by definition concern only international armed conflicts, are not only war crimes but are further considered “grave breaches”. These acts include torture, biological experiments, extensive destruction of property, deportation, and the taking of hostages.

Acts such as torture, rape, enslavement and unlawful imprisonment can all be punishable either as ordinary crimes, war crimes, or crimes against humanity, depending on the circumstances.

One significant difference is that war crimes can be committed during armed conflict only, while crimes against humanity can be committed at any time, including peace time or in situations of violence that do not amount to armed conflict.

Another difference between war crimes and crimes against humanity is that war crimes may be individual and isolated acts, whereas crimes against humanity are crimes committed on a large scale. What really counts, however, is the legal definition. In legal terms, crimes against humanity are crimes committed as part of a widespread or systematic attack directed against any civilian population.

For example, an isolated act of rape committed in connection with an armed conflict is clearly a war crime. However, if it is committed as part of a widespread or systematic pattern of rape of civilians, it is a crime against humanity.

So, how does one know whether a particular act qualifies as a crime against humanity?

At least one of the following conditions must be met:

1. The acts must be committed as part of a widespread attack directed against the civilian population. The attack must be committed on a large-scale and involve a large number of victims.

For example, in the Akayesu case, the International Criminal Tribunal for Rwanda, or ICTR, defined “widespread” as “massive, frequent, large scale action, carried out collectively with considerable seriousness and directed against a multiplicity of victims”.

2. The acts must be committed as part of a systematic attack against the civilian population. The attacks must be organized.

In the same case, the ICTR defined “systematic” as “thoroughly organized and following a regular pattern on the basis of a common policy involving substantial public or private resources”. It further stated that “there is no requirement that this policy must be adopted formally as the policy of a state. There must however be some kind of preconceived plan or policy”. In both cases, the perpetrator must know of the attack and realize that his or her acts are part of that attack.

The term genocide was not coined until the Second World War. It is a combination of two words: the Greek ‘genos’, meaning birth or kind and the Latin ‘caedere’, meaning to kill or to massacre. It thus means people being killed or massacred for what they are.

According to the legal definition in the Statute of the International Criminal Court, the crime of genocide is committed when any of the acts listed in Article 6 is “committed with intent to destroy, in whole or in part, a national, ethnical, racial or religious group, as such”.

Under international criminal law governing war crimes, crimes against humanity and genocide, individuals are criminally responsible for their actions, or failure to act. Only individuals can be found responsible for these crimes, not entities, such as organized armed groups, political parties, organisations or States. The position, rank and allegiance of the perpetrator are all irrelevant.

Behaviour that may lead to individual responsibility includes: actually committing a crime, contributing to it (e.g. as an accomplice), facilitating the commission of a crime (e.g. by gathering the victims in one place to later kill them, providing the weapon, planning a crime which is later perpetrated by others, instigating or prompting another person to commit a crime), or ordering that a crime be committed. Those who follow illegal orders can also be found individually responsible for crimes committed pursuant to such orders. We’ll look at this more closely in a few minutes.

Those with a responsibility to prevent or punish such crimes, have, in legal terms, command or superior responsibility. To be criminally responsible under the notion of superior responsibility, it is not necessary to be a superior in the military sense (e.g. a commander of soldiers). A person can also be a superior in the civilian sense. Hence, superiors include not only military commanders, but also police officers, prefects (such as in the conflict in Rwanda), or even mayors of cities or business leaders. What matters is not the formal link between one person and another, but the fact that one person is in the position to prevent another committing or contributing to a crime, and punish those who commit international crimes.

Of course, the superior must be aware that the subordinate is about to commit a crime or has committed a crime.

If so, the superior must make enquiries in order to prevent the crime or punish the perpetrator, as the case may be. Failure to do so may lead to criminal responsibility. The rationale behind superior responsibility is that a superior’s knowledge of and failure to punish his subordinates’ crimes could be understood by his subordinates as acceptance, if not encouragement, of such conduct. This may increase the risk of new crimes being committed.

The duty to prevent or punish crimes is not absolute. This is because a superior cannot be expected to stop crimes or punish the perpetrators in all circumstances. However, he or she must take all the measures within his or her power to ensure that appropriate disciplinary or criminal prosecution processes are followed, or alternatively refer the matter to a competent person or authority (usually a higher-ranking military officer or a public official).

The key point concerning illegal orders is that a soldier does not escape criminal responsibility if he obeys a manifestly illegal order – even a direct order from superiors.

However, the International Criminal Court (ICC) Statute contains a limited exception, or as it is called in legal terms the “duress defence”. It excludes criminal responsibility for conduct “caused by duress resulting from a threat of imminent death or of continuing or imminent serious bodily harm against that person (i.e. the perpetrator) or another person, and the person acts necessarily and reasonably to avoid this threat, provided that the person does not intend to cause a greater harm than the one sought to be avoided”.

Given the nature of genocide and crimes against humanity, the duress defence is unlikely to apply in cases where an accused has harmed multiple victims. That said, where the court accepts that the perpetrator was acting under some form of duress but finds that this defence does not apply, the perpetrator may receive a lighter sentence than would otherwise be imposed. Interestingly, unlike the ICC Statute, the Statutes of the International Criminal Tribunal for the former Yugoslavia and the International Criminal Tribunal for Rwanda provide for no duress defence.

The question arises, what can be done if a war crime, a crime against humanity or genocide has been committed? As we will see below, judicial or non-judicial methods may be used to deal with international crimes. As you perhaps already know, deciding what is the most appropriate method of addressing international crimes, that is judicial methods, non-judicial methods or a combination of the two, is the subject of much debate. Rather than entering into the discussion we will merely present you the available options.


Regarding the judicial methods of dealing with international crimes, all States are now bound by the Four Geneva Conventions of 1949. Under these treaties they have pledged to ensure that the laws of war are respected and enforced. Specifically, this means that all States must ensure that their own laws, military manuals and other regulations give force to the many articles contained in the Four Geneva Conventions.

In addition, States must implement these laws. This requires investigation of allegations of war crimes committed by their own nationals, including members of their armed forces, as well as other international crimes committed on their territory. States must also ensure alleged offenders are prosecuted in accordance with international standards.

However, beyond the obligation to prosecute their own nationals, States must also ensure that foreign nationals who have allegedly committed grave breaches of the Geneva Conventions or the First Additional Protocol of 1977 do not enjoy impunity, or, in plain English, do not get away with it (whether at home or in a foreign safe haven). In this context, the principle of universal jurisdiction is relevant.

According to the principle of universal jurisdiction, some international crimes are so serious that States are obliged to bring the perpetrators to justice, regardless of their nationality or the place of the crime. This is a principle of customary law which means that all States must follow it.

States must either prosecute the perpetrators in their own courts or facilitate their prosecution elsewhere. The principle has been invoked with respect to both serious violations of the laws and customs of war and grave breaches of the Geneva Conventions. The Statute of the International Criminal Court requires States that are bound by this treaty to arrest and either prosecute or extradite perpetrators of crimes listed in the Statute.

The trial of Adolf Eichmann (for his role in the Holocaust during the Second World War) before the Jerusalem District Court in 1961 was the first (and most famous) example of the application of the principle of universal jurisdiction by a national court. In its judgment, the District Court stated that Eichmann had committed “crimes which offended the whole of mankind and shocked the conscience of nations” and “grave offences against the law of nations itself”. After tracing the natural-law origins of the principle, the court found that “the jurisdiction to try crimes under international law is universal”.

Other examples are the trials following the genocide in Rwanda and the conflict in the former Yugoslavia. For example, the Mayor of Mushubati (a district of Rwanda) was brought before a Swiss military court in 1999. He was convicted of a range of crimes committed during the 1994 genocide, including war crimes.

While the primary responsibility to search for and prosecute the perpetrators of international crimes lies with States, history has shown that other legal mechanisms can also be used:

International tribunals (such as the ad hoc tribunals for the former Yugoslavia and Rwanda), the International Criminal Court (ICC) and mixed tribunals and courts (including those for Timor-Leste, Sierra Leone and Cambodia).

Here we look at the two ad hoc tribunals created by the UN Security Council in response to specific conflicts: the International Criminal Tribunal for the former Yugoslavia, or ICTY, has jurisdiction to deal with the crimes committed in the former Yugoslavia since 1991, whereas the International Criminal Tribunal for Rwanda, or ICTR, can deal with crimes committed in Rwanda in 1994.

They share the following features:

– they deal with similar categories of crimes: war crimes, crimes against humanity and genocide;

– they prosecute individuals, not States or political organizations;

– they were created for a specific context.

These two tribunals have made a significant contribution to the development of international criminal law. For example they have:

– clarified through case law the nature and scope of international crimes;

– inspired the establishment of other courts and tribunals to try international crimes;

– strengthened interest in the enforcement of IHL – an important example is the conviction of soldiers for acts of rape during an armed conflict. Rape was long considered a feature of war. The ICTY and the ICTR have send a different message by convicting various individuals of rape as a war crime, rape as a crime against humanity, and even an act of genocide.

The other judicial bodies that deal with international crimes are mixed tribunals and courts. They are established by the State where the crimes have occurred, with the support or influence of the United Nations. UN involvement is often evident from the logos of these courts.

These courts combine international and national aspects (judges, law, experts, etc.) and apply international criminal law rules on judicial guarantees, the elements of international crimes etc. Further, these courts and tribunals were all established to deal with a particular situation. Most deal only with crimes committed during a specific period of time. Examples include Timor-Leste, Sierra Leone and Cambodia.

Mixed courts and tribunals offer a number of advantages. They are often made up of both international judges and local judges and prosecutors, who are well informed about the circumstances in which the crimes were committed and who know the laws of the country and speak its languages. The administration of justice therefore reflects local realities more accurately than would be possible with an international tribunal, especially one set up abroad. A mixed tribunal may therefore be more readily accepted by the local population than international judicial proceedings taking place far away in another country.

The International Criminal Court, or ICC, differs from the ad hoc and mixed tribunals that are the product of a United Nations resolution or an agreement between States and the United Nations. Instead, the ICC was created by a multilateral treaty between States that was signed in Rome in 1998 (this is why this treaty is also referred to as the Rome Statute).

The ICC was not established to deal with a specific situation at a given time and is therefore not intended to be closed in the short to medium term. Instead it is meant to last: it is the first permanent international court to deal with the prosecution of individuals responsible for the most serious of international crimes.

The ICC has jurisdiction to try individuals accused of war crimes, crimes against humanity and genocide committed after 1 July 2002 (the date of entry into force of the ICC Statute). It will also have jurisdiction to try individuals accused of the crime of aggression, once the conditions for the exercise of the Court’s jurisdiction over the latter are fulfilled this crime have been met.

Non-judicial methods may have reparative, truth-seeking and reconciliatory functions. The use of such methods reflects the desire of many societies to find their way back to peace and leave the legacy of armed conflict behind them.

By choosing non-judicial methods to deal with violations, States decide to acknowledge and analyse atrocities and focus on the losses suffered by the victims rather than on punishing perpetrators. The aim is to understand and learn from the past in order to prevent atrocities in the future. There are many examples of measures taken to compensate the victims of international crimes for the loss and damage they have suffered:

Germany decided to offer financial compensation for survivors of the Nazi concentration camps and the families of those who perished in the camps.

In Chile, the government pays a monthly allowance to family members of those who disappeared or were killed under the military dictatorship of Augusto Pinochet.

In 1999, Kofi Annan, the Secretary-General of the United Nations, apologized for his organization’s failure to protect the people of the former Yugoslavia and Rwanda.

A number of States have erected monuments, built museums, opened their archives or revised their history books in an effort to acknowledge and own up to their past.

Truth commissions were established in a number of contexts to investigate international crimes and establish their causes, in order to help societies come to terms with the past and to prevent atrocities from happening again. Truth commissions hear the testimony of victims, witnesses and perpetrators, but they are not trials. They are only forums of inquiry to determine the facts of past atrocities.

They are usually established by governments and issue recommendations on how governments should deal with atrocities in order to facilitate peace and community reconciliation. Truth commissions have been created in a number of countries, including: Argentina, Chad, Ecuador, El Salvador, Guatemala, Haiti, Nigeria, Panama and Uganda.

In many instances, truth commissions have also sought to permit reconciliation between perpetrators and their victims and the victims’ families. Truth and reconciliation commissions have been set up in: Chile, Timor-Leste, Ghana, Liberia, Morocco, Northern Ireland, Peru, Sierra Leone, South Africa and South Korea.

The ICRC supports all efforts to promote respect for IHL and to strengthen the fight against impunity.

The ICRC is not a court. The work of international criminal courts and tribunals and that of the ICRC are alternative and complementary approaches to preventing violations of international humanitarian law. Although their ultimate objectives are the same, they use very different tools to achieve them. The ICC, for example, prosecutes and sanctions whereas the ICRC promotes respect for international humanitarian law through confidential dialogue and persuasion.

The ICRC has a clear and long-established practice of not becoming involved in judicial proceedings and of not disclosing what it discovers during its work. This practice is grounded in extensive experience in the field and in the organization’s utmost respect for confidentiality. The ICRC does not hesitate to remind those involved in armed conflicts – be they governments or non-State armed groups – of their obligations under international humanitarian law. However, as a neutral and independent organization, the ICRC strongly believes that it will only be able to do this by ensuring continuous and confidential dialogue with all parties to the conflict.