Defining Core International Crimes: How Does the International Criminal Court (ICC) Prosecute Genocide, War Crimes, and Crimes Against Humanity?

Japanese Attorney at Law - Bengoshi L.L.

• 10 min read

The 20th and early 21st centuries have witnessed an unprecedented effort by the international community to define and prosecute individuals responsible for the most egregious atrocities that "shock the conscience of humankind." This endeavor led to the establishment of ad hoc tribunals like those at Nuremberg and Tokyo after World War II, and later for the former Yugoslavia (ICTY) and Rwanda (ICTR). Culminating these efforts, the Rome Statute created the International Criminal Court (ICC) in 1998 (entering into force in 2002) as a permanent institution to investigate and try individuals for a specific set of "most serious crimes of concern to the international community as a whole." This article defines these core international crimes—genocide, crimes against humanity, and war crimes (and briefly, the crime of aggression)—and examines how the ICC prosecutes them.

What Are Core International Crimes?

The jurisdiction of the ICC is limited to a few specific categories of crimes, meticulously defined in the Rome Statute. These are distinct from transnational crimes like drug trafficking or money laundering, which, while serious, are generally prosecuted within national legal systems, albeit with international cooperation.

A. Genocide (Article 6, Rome Statute)

Genocide is often referred to as the "crime of crimes." Its definition in the Rome Statute mirrors that of the 1948 Convention on the Prevention and Punishment of the Crime of Genocide. It requires a specific intent (dolus specialis) to destroy, in whole or in part, a national, ethnical, racial, or religious group, as such. This intent is the defining characteristic and often the most difficult element to prove.

The underlying prohibited acts, when committed with this specific intent, include:

  • Killing members of the group.
  • Causing serious bodily or mental harm to members of the group.
  • 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.
  • Forcibly transferring children of the group to another group.

The phrase "in whole or in part" means the intent does not need to be to destroy the entire group globally, but a substantial part of it. "As such" signifies that the victims are targeted because of their membership in the protected group.

B. Crimes Against Humanity (CAH) (Article 7, Rome Statute)

Crimes against humanity are certain acts when committed as part of a "widespread or systematic attack directed against any civilian population, with knowledge of the attack." Unlike genocide, CAH does not require a specific intent to destroy a particular group. Unlike war crimes (discussed below), CAH can be committed during peacetime as well as during armed conflict.

Key elements include:

  • Contextual Element: The acts must be part of a "widespread or systematic attack directed against any civilian population."
    • "Attack directed against any civilian population" means a course of conduct involving the multiple commission of acts referred to below against any civilian population, pursuant to or in furtherance of a State or organizational policy to commit such attack.
    • "Widespread" refers to the scale of the acts or the number of victims.
    • "Systematic" refers to the organized nature of the acts and the improbability of their random occurrence.
  • Knowledge of the Attack: The perpetrator must have known that their acts were part of this widespread or systematic attack.

The underlying prohibited acts enumerated in Article 7(1) include:

  • 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, sexual slavery, enforced prostitution, forced pregnancy, enforced sterilization, or any other form of sexual violence of comparable gravity;
  • Persecution against any identifiable group or collectivity on political, racial, national, ethnic, cultural, religious, gender, or other grounds that are universally recognized as impermissible under international law, in connection with any act referred to in this paragraph or any crime within the jurisdiction of the Court;
  • Enforced disappearance of persons;
  • The crime of apartheid;
  • Other inhumane acts of a similar character intentionally causing great suffering, or serious injury to body or to mental or physical health.

C. War Crimes (Article 8, Rome Statute)

War crimes are serious violations of the laws and customs applicable in international or non-international armed conflict. The Rome Statute provides an extensive list of acts constituting war crimes, drawing heavily from the Geneva Conventions of 1949 and customary international humanitarian law. A crucial element is the nexus to an armed conflict: the act must have been committed in the context of and associated with an armed conflict.

Article 8 categorizes war crimes as follows:

  1. Grave breaches of the Geneva Conventions of 1949 (applicable in international armed conflict – IAC), such as:
    • Wilful killing, torture or inhuman treatment, wilfully causing great suffering or serious injury to body or health, extensive destruction and appropriation of property not justified by military necessity and carried out unlawfully and wantonly, compelling a prisoner of war or other protected person to serve in the forces of a hostile Power, wilfully depriving a prisoner of war or other protected person of the rights of fair and regular trial, unlawful deportation or transfer or unlawful confinement, taking of hostages.
  2. Other serious violations of the laws and customs applicable in international armed conflict, such as:
    • Intentionally directing attacks against the civilian population or civilian objects;
    • Intentionally directing attacks against personnel, installations, material, units or vehicles involved in a humanitarian assistance or peacekeeping mission;
    • Intentionally launching an attack in the knowledge that such attack will cause incidental loss of life or injury to civilians or damage to civilian objects or widespread, long-term and severe damage to the natural environment which would be clearly excessive in relation to the concrete and direct overall military advantage anticipated;
    • Attacking or bombarding, by whatever means, towns, villages, dwellings or buildings which are undefended and which are not military objectives;
    • Killing or wounding a combatant who, having laid down his arms or having no longer means of defence, has surrendered at discretion;
    • Pillage;
    • Employing poison or poisoned weapons, asphyxiating, poisonous or other gases, and all analogous liquids, materials or devices;
    • Employing bullets which expand or flatten easily in the human body;
    • Committing outrages upon personal dignity, in particular humiliating and degrading treatment;
    • Committing rape, sexual slavery, enforced prostitution, forced pregnancy, enforced sterilization, or any other form of sexual violence also constituting a grave breach of the Geneva Conventions;
    • Conscripting or enlisting children under the age of fifteen years into the national armed forces or using them to participate actively in hostilities.
  3. In the case of an armed conflict not of an international character (NIAC), serious violations of Article 3 common to the four Geneva Conventions, such as:
    • Violence to life and person, in particular murder of all kinds, mutilation, cruel treatment and torture;
    • Committing outrages upon personal dignity, in particular humiliating and degrading treatment;
    • Taking of hostages;
    • The passing of sentences and the carrying out of executions without previous judgement pronounced by a regularly constituted court, affording all the judicial guarantees which are generally recognized as indispensable.
  4. Other serious violations of the laws and customs applicable in armed conflicts not of an international character, such as:
    • Intentionally directing attacks against the civilian population as such or against individual civilians not taking direct part in hostilities;
    • Intentionally directing attacks against buildings dedicated to religion, education, art, science or charitable purposes, historic monuments, hospitals and places where the sick and wounded are collected, provided they are not military objectives;
    • Pillage;
    • Committing rape, sexual slavery, enforced prostitution, forced pregnancy, enforced sterilization, or any other form of sexual violence also constituting a serious violation of common Article 3;
    • Conscripting or enlisting children under the age of fifteen years into armed forces or groups or using them to participate actively in hostilities.

The Rome Statute's extensive list in Article 8 attempts to codify many rules that were previously considered customary.

D. The Crime of Aggression

The Rome Statute (Article 5) also includes the crime of aggression within the ICC's jurisdiction. However, at the time of the Statute's adoption in 1998, the definition of aggression and the conditions for the Court's exercise of jurisdiction over it were left for future agreement.

These were subsequently adopted at the Kampala Review Conference in 2010 through amendments to the Rome Statute, which introduced Article 8 bis defining the crime of aggression. The definition includes "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" means the use of armed force by a State against the sovereignty, territorial integrity or political independence of another State, or in any other manner inconsistent with the Charter of the United Nations. Examples listed include invasion, bombardment, blockade, and attack by armed forces.

The ICC's jurisdiction over the crime of aggression was activated in July 2018, subject to specific jurisdictional conditions, including potential referrals by the UN Security Council or, under certain circumstances, initiation by the Prosecutor if the Security Council has not made a determination of aggression.

The International Criminal Court (ICC): Mandate and Functioning

The ICC is a permanent, treaty-based international court with the mandate to investigate and prosecute individuals (not states or organizations) accused of committing the core international crimes.

Jurisdictional Reach

The ICC's jurisdiction is governed by several principles:

  • Subject-Matter Jurisdiction (Ratione Materiae): As outlined above, the Court's jurisdiction is limited to genocide, crimes against humanity, war crimes, and (since 2018) the crime of aggression.
  • Temporal Jurisdiction (Ratione Temporis): The ICC can only prosecute crimes committed after the entry into force of the Rome Statute, which was July 1, 2002 (Article 11). For states that join after this date, jurisdiction generally begins from the date their membership becomes effective, unless they make a special declaration accepting jurisdiction retroactively.
  • Personal and Territorial Jurisdiction (Ratione Personae and Ratione Loci): The Court may exercise jurisdiction if (Article 12):
    • The alleged crimes were committed on the territory of a State Party to the Rome Statute or a State that has made a special declaration accepting the Court's jurisdiction for the crimes in question.
    • The person accused of the crime is a national of a State Party or a State that has made such a special declaration.
    • An exception is when a situation is referred to the ICC Prosecutor by the UN Security Council acting under Chapter VII of the UN Charter. In such cases, the ICC may have jurisdiction regardless of the nationality of the accused or the location of the crime (as seen with the situations in Darfur/Sudan and Libya, neither of which are States Parties).
  • The Principle of Complementarity (Articles 1, 17): This is a cornerstone of the Rome Statute. The ICC is intended to be a court of last resort, complementing national criminal jurisdictions. It can only step in if the relevant national authorities are "unwilling or genuinely unable" to carry out the investigation or prosecution genuinely. This respects state sovereignty while ensuring that impunity for the most serious crimes is avoided.

Triggering ICC Investigations (Article 13)

An ICC investigation can be initiated in one of three ways:

  1. Referral by a State Party: A State Party to the Rome Statute can refer a situation in which one or more crimes within the Court's jurisdiction appear to have been committed to the Prosecutor.
  2. Referral by the UN Security Council: The Security Council, acting under Chapter VII of the UN Charter, can refer a situation to the Prosecutor. This can grant the ICC jurisdiction even over situations involving non-States Parties.
  3. Proprio Motu Investigation by the Prosecutor: The ICC Prosecutor can initiate investigations on his or her own initiative (proprio motu) on the basis of information received regarding crimes within the Court's jurisdiction. However, such an investigation requires authorization from a Pre-Trial Chamber of the Court.

The Prosecution Process at the ICC

The ICC's legal process involves several stages and distinct organs:

  • The Presidency: Responsible for the proper administration of the Court (except the Office of the Prosecutor).
  • The Chambers: Comprised of the Pre-Trial Division, Trial Division, and Appeals Division.
  • The Office of the Prosecutor (OTP): An independent organ responsible for receiving referrals and information, conducting preliminary examinations and investigations, and prosecuting cases before the Court.
  • The Registry: Responsible for the non-judicial aspects of the Court's administration and servicing.

The typical process involves:

  1. Preliminary Examination: The OTP assesses available information to determine if there is a reasonable basis to proceed with a formal investigation.
  2. Investigation: If an investigation is initiated, the OTP gathers evidence. It may seek cooperation from states or conduct on-site investigations.
  3. Issuance of Arrest Warrants or Summonses: If the Prosecutor finds sufficient evidence, they can request a Pre-Trial Chamber to issue an arrest warrant or a summons to appear.
  4. Confirmation of Charges Hearing: Before a case goes to trial, a Pre-Trial Chamber holds a hearing to determine if there is sufficient evidence to establish substantial grounds to believe that the person committed each of the crimes charged.
  5. Trial: If charges are confirmed, the case proceeds to a Trial Chamber, which conducts the trial, hears evidence from the prosecution and defense, and ultimately delivers a judgment.
  6. Judgment and Sentencing: If the accused is convicted, the Trial Chamber imposes a sentence (imprisonment up to 30 years, or a life sentence in exceptional circumstances).
  7. Appeals: Both the Prosecutor and the convicted person can appeal the judgment or sentence to the Appeals Chamber on grounds of procedural error, error of fact, or error of law.
  8. Enforcement of Sentences: Sentences of imprisonment are served in states that have agreed to accept convicted persons.

Rights of the Accused and Participation of Victims:
The Rome Statute guarantees extensive rights for the accused, including the presumption of innocence, the right to a fair and public hearing, the right to counsel, and the right to examine witnesses.
A distinctive feature of the ICC is the provision for victims to participate in proceedings, even if not as formal parties, and to present their views and concerns at appropriate stages. The Statute also envisages the possibility of reparations to victims.

Challenges and Perspectives for the ICC

The ICC represents a significant advancement in international criminal justice, but it faces numerous challenges:

  • State Cooperation: The ICC has no police force of its own and relies entirely on the cooperation of states for arrests, the surrender of suspects, the collection of evidence, and the enforcement of sentences. Lack of cooperation, particularly from non-States Parties or states where crimes occurred, is a major obstacle.
  • Political Realities and Selectivity: The ICC has faced accusations of political bias and of disproportionately focusing its investigations on situations in Africa, though the OTP has expanded its preliminary examinations to other regions. The influence of the UN Security Council (especially the P5 members) in referring or deferring situations also raises political complexities.
  • Relationship with Non-States Parties: The position of major global powers that are not party to the Rome Statute (such as the United States, Russia, and China) significantly impacts the Court's reach and effectiveness. The U.S. position, for example, has fluctuated, ranging from opposition to cautious engagement. (The PDF mentions the US and ICC in COLUMN 5-11).
  • Resource Constraints: Investigations and trials are complex and expensive, and the Court operates under budgetary limitations.
  • Achieving Justice and Deterrence: The ultimate impact of the ICC in delivering justice to victims and deterring future atrocities is a subject of ongoing debate and will likely take many years to assess fully. The Court's limited capacity means it can only prosecute a small fraction of potential cases.

Despite these challenges, the ICC remains a vital symbol of the international community's commitment to ending impunity for the gravest crimes. Its ongoing work, alongside other internationalized and national efforts, contributes to the slow but steady development of a global system of international criminal justice.

Conclusion

Defining and prosecuting core international crimes—genocide, crimes against humanity, war crimes, and the crime of aggression—is a complex but essential endeavor for upholding fundamental human values and maintaining international peace and security. The International Criminal Court serves as the central permanent institution in this global effort, striving to ensure that individuals who commit these atrocities are held accountable. While the ICC faces significant political, practical, and resource-related hurdles, its existence and operations represent a crucial step towards a world where impunity for the "most serious crimes of concern to the international community" is no longer the norm.