International Criminal Law — ICC, Crimes Against Humanity

International criminal law is the branch of international law that places obligations directly on individuals — not just on States — and provides for their prosecution before international or internationalised tribunals for a defined set of grave offences. Its foundational proposition was set down at Nuremberg in 1946: international law imposes duties and liabilities upon individuals as well as upon States, because crimes against international law are committed by men, not by abstract entities, and only by punishing individuals who commit such crimes can the provisions of international law be enforced. The four core crimes the field now centres on are genocide, crimes against humanity, war crimes, and the crime of aggression. The architecture rests on the four 1949 Geneva Conventions, the 1948 Genocide Convention, the customary law of war crimes and crimes against humanity, and — since 2002 — the Rome Statute of the International Criminal Court. This chapter places that machinery within the wider international law for judiciary notes on this site.

For the judiciary aspirant, the rules to know are the doctrinal core. You need the historical line from Nuremberg through the ad hoc tribunals to the ICC; the four core crimes and their definitions; the jurisdictional rules of the Rome Statute; the principle of complementarity; the doctrine of command responsibility; the rejection of the absolute defence of superior orders; and the position of India.

The pre-1945 background — piracy, slave trading and a narrow field

Before the Second World War, the range of offences for which individuals bore international responsibility was narrow. Piracy jure gentium and slave trading were the longstanding examples. Piracy was — and remains — defined under treaty (Article 15 of the 1958 High Seas Convention; Article 101 of the 1982 Convention on the Law of the Sea) as illegal acts of violence, detention or depredation committed for private ends by the crew or passengers of a private ship or aircraft and directed against another ship or aircraft on the high seas or in a place outside the jurisdiction of any State. Universal jurisdiction over piracy is a long-established principle: any State may arrest and try pirates regardless of nationality or place of commission, a topic developed in the chapter on territorial, personal and universal jurisdiction and rooted in the regime under the UNCLOS provisions on the high seas. Beyond piracy and slave trading, however, jurisdiction was practically confined to domestic courts and prosecutions for offences with international elements were rare.

Nuremberg and Tokyo — the founding moment

The Charter annexed to the London Agreement of 8 August 1945 for the Prosecution and Punishment of the Major War Criminals provided expressly for individual responsibility for crimes against peace, war crimes, and crimes against humanity, with a separate conspiracy charge. The International Military Tribunal sitting at Nuremberg, composed of four principal judges (from the United States, the United Kingdom, the USSR and France) and four alternates, was the first international criminal tribunal. Its 1946 judgment affirmed that international law imposes duties and liabilities upon individuals as well as upon States and that the absolute defence of superior orders cannot be sustained where a moral choice is in fact possible. The International Military Tribunal for the Far East, established in January 1946 to deal with Japanese war crimes, was composed of judges from eleven States and reaffirmed the Nuremberg legal findings, including the criminality of aggressive war and the rejection of superior orders as an absolute defence. The General Assembly affirmed the principles of the Nuremberg Charter and judgment in 1946 and stated that genocide was a crime under international law bearing individual responsibility — a position reaffirmed in the Genocide Convention of 1948.

Genocide — the 1948 Convention

The Convention on the Prevention and Punishment of the Crime of Genocide, adopted on 9 December 1948 and in force since 12 January 1951, defines genocide in Article II as any of a series of enumerated acts — killing members of the group; causing serious bodily or mental harm; deliberately inflicting on the group conditions of life calculated to bring about its physical destruction in whole or in part; imposing measures intended to prevent births within the group; and forcibly transferring children of the group to another group — committed with intent to destroy, in whole or in part, a national, ethnical, racial or religious group, as such. Article III makes punishable not only the act of genocide but also conspiracy, direct and public incitement, attempt and complicity. Article IV provides that persons committing genocide or any of the other acts enumerated shall be punished, whether they are constitutionally responsible rulers, public officials, or private individuals. Article VI provides for trial by a court in the territory where the act was committed or by an international penal tribunal. The dolus specialis — the specific intent to destroy the group as such — is the hallmark of the crime and the most heavily litigated element. India ratified the Genocide Convention on 27 August 1959. The treaty machinery used to give effect to the obligation in domestic systems is the same machinery considered in the chapter on treaty formation, validity and termination under the Vienna Convention rules.

The ad hoc tribunals — ICTY and ICTR

The renewed interest in international criminal jurisdiction in the 1990s led to the creation of two specific tribunals by the UN Security Council acting under Chapter VII of the Charter — both binding on all UN member States. The International Criminal Tribunal for the former Yugoslavia (ICTY) was established by Security Council resolution 827 (1993), with the power to prosecute persons responsible for serious violations of international humanitarian law committed in the territory of the former Yugoslavia since 1991. The International Criminal Tribunal for Rwanda (ICTR) was established by Security Council resolution 955 (1994), with jurisdiction over serious violations of international humanitarian law committed in the territory of Rwanda and by Rwandan citizens in the territory of neighbouring States between 1 January and 31 December 1994. The Statutes of the two tribunals share a common architecture — Trial Chambers, Office of the Prosecutor, Registry — and originally a single Appeals Chamber to ensure consistency.

Articles 2 to 5 of the ICTY Statute lay down the substantive jurisdiction: grave breaches of the Geneva Conventions of 1949, violations of the laws or customs of war, genocide, and crimes against humanity. The ICTR Statute parallels this with genocide, crimes against humanity (the listed acts being murder, extermination, enslavement, deportation, imprisonment, torture, rape, persecutions and other inhumane acts when committed as part of a widespread or systematic attack against any civilian population on national, political, ethnic, racial or religious grounds), and violations of common Article 3 and APII. The two tribunals adopted parallel articles establishing individual criminal responsibility — including for planning, instigating, ordering, committing or otherwise aiding and abetting; the irrelevance of official position; superior responsibility where the superior knew or had reason to know of the subordinate’s conduct and failed to take necessary and reasonable measures; and superior orders not relieving criminal responsibility but possibly mitigating punishment. The ICTY Appeals Chamber in Prosecutor v. Tadić confirmed that customary international law had imposed criminal responsibility for serious violations of humanitarian law in internal as well as international armed conflicts, and articulated the ‘overall control’ test for attributing the conduct of armed groups to a State, a test that operates alongside the State-attribution rules examined in the chapter on recognition and succession of States. The ICTR delivered the first international conviction of a former head of government for genocide in Prosecutor v. Kambanda (1998) and, in Prosecutor v. Akayesu (1998), the first international interpretation of the Genocide Convention and the first international definition of rape as an instrument of genocide.

The International Criminal Court — Rome Statute, 1998

Article VI of the Genocide Convention envisaged trial of persons charged with genocide either by a court in the territory where the act had been committed or by an international penal tribunal to be established. The proposal lay dormant for decades. After the Yugoslav and Rwandan tribunals demonstrated the utility of international criminal jurisdiction, the International Law Commission produced a Draft Statute in 1994. A Preparatory Committee in 1995 led to the Rome Conference of 1998, which adopted the Rome Statute on 17 July 1998. Sixty ratifications were required for entry into force; this was achieved on 1 July 2002. Unlike the ad hoc tribunals, the ICC is the product of a multilateral treaty rather than a binding Security Council resolution.

The Statute is far broader than the ICTY/ICTR Statutes, containing 128 Articles. Article 5 confines the jurisdiction of the Court to the most serious crimes of concern to the international community as a whole: genocide (Article 6), crimes against humanity (Article 7), war crimes (Article 8) and aggression (Article 8 bis, added by the 2010 Kampala amendments and activated for jurisdictional purposes in 2018). Article 25 establishes individual criminal responsibility — a person who commits a crime within the jurisdiction of the Court shall be individually responsible and liable for punishment. The Court has jurisdiction only with respect to crimes committed after the Statute came into force for the State concerned (Article 11), so its jurisdiction is non-retroactive.

The four core crimes under the Rome Statute

Article 6 reproduces the Genocide Convention definition verbatim — the same five enumerated acts committed with intent to destroy, in whole or in part, a national, ethnical, racial or religious group, as such. The dolus specialis remains the controlling element.

Article 7 defines crimes against humanity as a list of acts — murder, extermination, enslavement, deportation or forcible transfer of population, imprisonment or other severe deprivation of physical liberty in violation of fundamental rules of international law, torture, rape and other forms of sexual violence (sexual slavery, enforced prostitution, forced pregnancy, enforced sterilisation), persecution against any identifiable group on political, racial, national, ethnic, cultural, religious, gender or other grounds universally recognised as impermissible under international law, enforced disappearance, the crime of apartheid, and other inhumane acts of a similar character intentionally causing great suffering or serious injury to body or to mental or physical health — when committed as part of a widespread or systematic attack directed against any civilian population, with knowledge of the attack. The chapeau (the ‘widespread or systematic’ element and the State or organisational policy element) is what elevates the underlying acts from ordinary crime to crimes against humanity.

Article 8 defines war crimes by reference to the four 1949 Geneva Conventions and to the laws and customs applicable in international and non-international armed conflict. The grave breaches enumerated in the Geneva Conventions are the spine of the article; numerous additional categories are listed for international armed conflict (Article 8(2)(b)) and for non-international armed conflict (Article 8(2)(c) and (e)), drawing on the Hague Regulations and customary law. The full content of these provisions belongs to the chapter on international humanitarian law and the Geneva Conventions.

Article 8 bis defines the crime of aggression as the planning, preparation, initiation or execution, by a person in a position effectively to exercise control over or to direct the political or military action of a State, of an act of aggression which, by its character, gravity and scale, constitutes a manifest violation of the Charter of the United Nations. An ‘act of aggression’ is defined by reference to General Assembly resolution 3314 (XXIX) of 1974. The jurisdictional regime for aggression is significantly narrower than for the other three crimes: the Court can exercise jurisdiction over aggression only with respect to State parties that have accepted the relevant amendments and not where a State has lodged a declaration of non-acceptance, and the Security Council retains a special role.

Jurisdictional reach of the ICC

Article 12 governs the basic jurisdictional preconditions. The Court may exercise jurisdiction with respect to a crime under Article 5 only where either the State on the territory of which the conduct in question occurred (or the State of registration of the vessel or aircraft if the crime was committed on board) is a party to the Statute, or the State of which the person accused is a national is a party. The jurisdiction of the ICC is therefore not universal. It is territorial or personal in nature. A national of a non-party State may nevertheless be prosecuted where the crime is committed on the territory of a State party. The Court may, in addition, exercise jurisdiction without the territorial or nationality preconditions where the situation is referred to the Prosecutor by the Security Council acting under Chapter VII (Article 13(b)). Such referrals have occurred with respect to Darfur (resolution 1593 of 2005) and Libya (resolution 1970 of 2011). The interaction between Council referrals and the consent-based jurisdictional regime echoes the wider question raised in the chapter on the nature and basis of international law.

Three modes of triggering ICC proceedings are available under Article 13: referral by a State party (Article 14); referral by the Security Council; and proprio motu initiation by the Prosecutor (Article 15), subject to authorisation by the Pre-Trial Chamber. Self-referrals by State parties have included Uganda (the Lord’s Resistance Army, 2003), the Democratic Republic of the Congo (2004), the Central African Republic (2004 and 2014), and Mali (2012). Proprio motu investigations have been authorised in respect of, among others, Kenya (2010), Côte d’Ivoire (2011) and Georgia (2016). Article 16 allows the Security Council to suspend an investigation or prosecution for renewable twelve-month periods.

Complementarity — the cornerstone of the ICC regime

The ICC differs from the ICTY and the ICTR in one principal way: it is founded on the principle of complementarity, under which national courts have priority. Article 17 lists the grounds on which a case is inadmissible before the Court. A case is inadmissible where it is being investigated or prosecuted by a State which has jurisdiction over it, unless the State is unwilling or unable genuinely to carry out the investigation or prosecution; where the case has been investigated and the State has decided not to prosecute, unless the decision resulted from unwillingness or inability genuinely to prosecute; and where the person concerned has already been tried for the conduct in question, save where the trial was for the purpose of shielding the person from criminal responsibility or was not conducted independently or impartially in accordance with the norms of due process recognised by international law. The case-law of the Appeals Chamber — in the Simone Gbagbo, Kenyatta and Gaddafi proceedings — has clarified that the State bears the burden of proof on inadmissibility, that ‘substantially the same conduct’ suffices for the purposes of complementarity, and that the State must produce evidence of a sufficient degree of specificity and probative value of concrete and progressive investigative steps.

Structure of the Court — chambers, prosecutor, registry

The Court has four organs: the Presidency; the Chambers (an Appeals Division, a Trial Division and a Pre-Trial Division); the Office of the Prosecutor; and the Registry. Eighteen judges are elected to nine-year terms by the Assembly of States Parties to represent the principal legal systems of the world, equitable geographical representation, and a fair representation of male and female judges. The Pre-Trial Chamber confirms or rejects authorisation to commence an investigation, makes a preliminary determination of jurisdiction and admissibility, holds the confirmation-of-charges hearing in the presence of the Prosecutor, the person charged and counsel, and may issue warrants of arrest and summonses. The Trial Chamber conducts the trial, ensures fairness and full respect for the rights of the accused with regard for the protection of victims and witnesses, and on conviction may impose imprisonment up to a maximum of thirty years or life imprisonment in cases of extreme gravity, fines, and orders for reparation, restitution or rehabilitation for victims. The Appeals Chamber may reverse or amend the decision, judgment or sentence or order a new trial.

Hybrid courts and internationalised tribunals

Outside the ad hoc tribunals and the ICC, a third model has developed in which international and national elements coexist in varying combinations. The most prominent examples are: the Special Court for Sierra Leone, established by an agreement between the UN and Sierra Leone in 2002 pursuant to Security Council resolution 1315 (2000), which convicted former Liberian President Charles Taylor of war crimes and crimes against humanity in 2012 and sentenced him to fifty years’ imprisonment; the Extraordinary Chambers in the Courts of Cambodia, established by agreement between the UN and Cambodia in 2003 to try the senior leaders of the Khmer Rouge regime, which convicted ‘Duch’ Khang Khek Ieu of crimes against humanity and grave breaches in 2010 (affirmed by the Supreme Court Chamber in 2012); the Kosovo Regulation 64 Panels and the Specialist Chambers and Specialist Prosecutor’s Office now sitting in The Hague; the East Timor Special Panels for Serious Crimes operating under the UN Transitional Administration; and the Bosnia War Crimes Chamber. The Mechanism for International Criminal Tribunals, established in 2010, has carried over residual functions of the ICTY and ICTR (witness protection, supervision of sentences, archives, trial of fugitives) and has branches in Arusha and The Hague. The peaceful-settlement procedures considered in the chapter on the settlement of international disputes sit alongside these criminal mechanisms as parallel ways of addressing the consequences of grave conflict.

Doctrines that recur across the field

Three doctrines recur across the entire field. First, individual criminal responsibility — affirmed at Nuremberg, codified in the Statutes of the ad hoc tribunals and Article 25 of the Rome Statute — means that international law speaks directly to the individual, not only through the State. Second, command (or superior) responsibility means that any person in a position of authority who orders the commission of a war crime or grave breach is as accountable as the subordinate committing it; and a superior who knew or, owing to the circumstances at the time, should have known that subordinates were committing or about to commit such crimes and failed to take all necessary and reasonable measures within his or her power to prevent or to punish them is criminally responsible (Rome Statute Article 28; ICTY Statute Article 7). Third, the absence of immunity for official position — Article 27 of the Rome Statute provides that the Statute applies equally to all persons without any distinction based on official capacity, including that of head of State or government, member of a government or parliament, elected representative or government official; and that immunities or special procedural rules attached to the official capacity of a person, whether under national or international law, shall not bar the Court from exercising jurisdiction. The defence of superior orders is substantially restricted: Article 33 of the Rome Statute makes it available only where the person was under a legal obligation to obey, did not know that the order was unlawful, and the order was not manifestly unlawful, with orders to commit genocide or crimes against humanity deemed manifestly unlawful as a matter of law.

India and the Rome Statute

India is a party to the Genocide Convention but has not signed or ratified the Rome Statute. The treatment of these grave-violation regimes in Indian courts also crosses the territory considered in the chapter on international human rights law, where many of the same prohibitions appear in their human-rights formulation. The principal Indian concerns articulated at the Rome Conference and afterwards include the inclusion of the crime of aggression without an agreed definition (now partly addressed by the 2010 Kampala amendments) and the powers of the Security Council under Articles 13(b) and 16 (which allow the Council to refer or suspend cases involving non-party States and risk overriding sovereign equality). India has nevertheless engaged with international criminal law through implementing the Genocide Convention conceptually within domestic offences and through the Geneva Conventions Act, 1960, which provides for prosecution of grave breaches in Indian courts. The constitutional framework for treaty implementation — Articles 51, 73 and 253 — is examined in the related material on the Indian Constitution and international law, and the dualist position is the same one explored in the chapter on the customary law and general principles.

What the exam wants you to remember

From this chapter, fix the following minimum: the Nuremberg Charter dates and its three categories of crime (crimes against peace, war crimes, crimes against humanity); the Genocide Convention definition (Article II) and the dolus specialis; the Security Council base of the ICTY (resolution 827, 1993) and the ICTR (resolution 955, 1994); the Rome Statute date (17 July 1998) and entry into force (1 July 2002); the four core crimes under Article 5 of the Statute; the territorial-or-nationality jurisdiction rule of Article 12 and the three triggers of Article 13; the principle of complementarity in Article 17; the rules on individual criminal responsibility (Article 25), command responsibility (Article 28), irrelevance of official capacity (Article 27) and the limited defence of superior orders (Article 33); and India’s position as a party to the Genocide Convention and the Geneva Conventions but not to the Rome Statute. With these in place you are ready for the standard objective and short-answer questions in the field, and you have the doctrinal vocabulary for the longer essay questions on the relationship between international criminal law, IHL, and human rights — connections developed across the linked chapters in these notes.

Frequently asked questions

What did Nuremberg actually decide for international law?

Two propositions, both restated and reinforced ever since. First, that international law imposes duties and liabilities upon individuals as well as upon States — crimes against international law are committed by men, not by abstract entities, and the only effective enforcement is to punish the individuals who commit them. Second, that the absolute defence of superior orders cannot be sustained where moral choice was in fact possible. The General Assembly affirmed the principles of the Nuremberg Charter and judgment in 1946, and they have since been treated as customary international law and incorporated into the Statutes of the ad hoc tribunals and the Rome Statute.

How is genocide defined and what is the dolus specialis?

Article II of the 1948 Genocide Convention — reproduced verbatim in Article 6 of the Rome Statute — defines genocide as any of five enumerated acts (killing members of the group; causing serious bodily or mental harm; deliberately inflicting conditions of life calculated to bring about physical destruction in whole or in part; imposing measures intended to prevent births within the group; forcibly transferring children of the group to another group) committed with intent to destroy, in whole or in part, a national, ethnical, racial or religious group, as such. The dolus specialis is the specific genocidal intent — the intent to destroy the group as such — and it is the controlling element that distinguishes genocide from other crimes that share the same physical acts.

What is complementarity under the Rome Statute and why does it matter?

Complementarity is the cornerstone principle of the ICC regime: national courts have priority and the ICC steps in only where national systems fail. Article 17 makes a case inadmissible where it is being or has been investigated or prosecuted by a State with jurisdiction, unless the State is unwilling or unable genuinely to carry out the investigation or prosecution, and where the person has already been tried, unless the trial was a sham. The Appeals Chamber in the Gbagbo, Kenyatta and Gaddafi cases has clarified that the State bears the burden of proving inadmissibility through evidence of concrete and progressive investigative steps covering substantially the same conduct.

Does the ICC have universal jurisdiction?

No. Article 12 of the Rome Statute provides that the Court may exercise jurisdiction only where either the State on whose territory the conduct occurred or the State of nationality of the accused is a party to the Statute. ICC jurisdiction is therefore territorial or personal, not universal. The exception is a Security Council referral under Chapter VII (Article 13(b)) — as for Darfur (resolution 1593, 2005) and Libya (resolution 1970, 2011) — where the territorial-or-nationality precondition does not apply because the source of jurisdiction is the binding Council resolution itself.

What is the difference between crimes against humanity and war crimes?

War crimes (Article 8 of the Rome Statute) require an armed conflict (international or non-international) and a sufficient nexus between the conduct and the conflict. They are defined chiefly by reference to grave breaches of the four 1949 Geneva Conventions and to other serious violations of the laws and customs of war. Crimes against humanity (Article 7) do not require an armed conflict. They require that the underlying act (murder, extermination, enslavement, deportation, torture, rape, persecution, enforced disappearance, apartheid, etc.) be committed as part of a widespread or systematic attack directed against any civilian population, in furtherance of a State or organisational policy, and with knowledge of the attack.

Why has India not joined the Rome Statute?

India has signalled several concerns since the Rome Conference in 1998. The principal ones are the powers conferred on the Security Council under Articles 13(b) and 16 — to refer cases involving non-parties to the Court or to suspend investigations — which India considers an inroad into sovereign equality and a politicisation of the prosecutorial function; concerns about the inclusion of the crime of aggression without (at the time) an agreed definition (partly addressed by the 2010 Kampala amendments); and broader doubts about the relationship between the ICC and the Indian constitutional scheme of treaty implementation under Articles 51, 73 and 253. India remains a party to the Genocide Convention and the four Geneva Conventions and prosecutes grave breaches under the Geneva Conventions Act, 1960.