International Criminal Law – How Was the International Criminal Court Created and How Does It Work in Practice?


I. Introduction
The International Criminal Court (ICC) is currently the only international criminal court established by a multilateral treaty and, importantly, the first and only permanent international criminal court in existence.
It formally came into operation on 1 July 2002, when its founding treaty—the Rome Statute of the International Criminal Court—entered into force. For decades, the idea of such a court had been cherished mainly by idealists and futurists. Yet, when 120 states voted in 1998 to adopt the Statute, the speed and breadth of support surprised even the Court’s strongest advocates.
Today, the ICC is an established institution. It is still not a fully central or “integral” pillar of the international system in the way the United Nations (UN) is, but it has become a serious and visible actor in the global legal and political landscape.
This text will:

1. Explain the historical background and key facts about the ICC;
2. Describe the powers of the Court; and
3. Outline the rights and obligations of states in relation to the ICC.

Later, you’ll find:

• 10 case scenarios with model “solutions”, showing how ICC rules apply in practice; and
• A critical analysis of the Court’s strengths, weaknesses, and challenges.

II. General
A. Establishment of the ICC
1. Early Origins of the Idea
The idea of a permanent international criminal court dates back to at least the 1920s. At that time, however, it remained largely theoretical and speculative. States were reluctant to relinquish criminal jurisdiction over individuals to any supranational body.
2. Post–Second World War Momentum and the Genocide Convention
After World War II, the UN General Assembly endorsed the Nuremberg Principles, confirming that individuals could be held criminally responsible under international law. This made the notion of a permanent court far more realistic.
The Convention on the Prevention and Punishment of the Crime of Genocide 1948 (Genocide Convention) captured this idea in Article VI. Instead of giving States Parties universal jurisdiction over genocide, Article VI provides that:

• Persons accused of genocide shall be tried before:
  • A competent court of the state where the act was committed, or
  • An international penal tribunal having jurisdiction over States Parties that accept it.

At the same time, in General Assembly Resolution 260 (III) of 9 December 1948, the UN General Assembly:

• Recognized that the evolving international community would increasingly need an international judicial organ for certain international crimes; and
• Requested the International Law Commission (ILC) to consider whether it was desirable and feasible to create such a court to try genocide and other crimes under international conventions.

3. ILC Work and the Early Stalemate
The International Law Commission worked on this issue until 1954. During this process, the idea of a court became entangled with the project to draft a Code of Offences Against the Peace and Security of Mankind.
The main obstacle was the definition of the crime of aggression. Disagreement over this issue caused the entire project to stall. In 1954, the UN General Assembly decided to postpone discussion of creating an international criminal jurisdiction. The matter was shelved again in 1957 and effectively remained dormant until the late 1980s.
4. Revival in the Late 1980s – Caribbean Initiative and ILC Draft Statute
In the late 1980s, a number of Caribbean states sought to revive the project, particularly because of concerns about large-scale drug trafficking and transnational organized crime.
The International Law Commission was again tasked with preparing proposals, this time linked to its revived work on the Draft Code of Crimes Against the Peace and Security of Mankind. Eventually, the court project was separated from the draft code, and in 1994 the ILC adopted a Draft Statute for an International Criminal Court (often called the ILC Draft Statute).
The ILC Draft Statute differed substantially from the later Rome Statute:

1. A procedural (“adjectival”) court
   • The court’s jurisdiction ratione materiae (subject-matter jurisdiction) extended to various crimes—both customary and treaty-based.
   • However, the Statute did not define these crimes itself.
   • Instead, judges would refer (“renvoi”) to:
     • applicable treaties,
     • principles and rules of general international law, and
     • relevant national law (as indicated in draft Article 33).

The crimes included:

• Genocide,
• Aggression,
• Serious violations of laws and customs of armed conflict,
• Crimes against humanity, and
• Crimes created under or pursuant to specific treaty provisions contained in an Annex, provided they amounted to “exceptionally serious crimes of international concern.”

The Annex covered crimes in major treaties, for example:

• Grave breaches of the Geneva Conventions of 1949,
• Offences under the Convention for the Suppression of Unlawful Seizure of Aircraft 1970,
• Torture under the Convention Against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment 1984 (Torture Convention),
• Drug trafficking offences under the United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances 1988.

1. No proprio motu powers for the Prosecutor
   • The Prosecutor could not open investigations on their own initiative.
   • Only the UN Security Council or States Parties could refer matters (referred to as “lodging complaints”).
2. Security Council primacy in Chapter VII situations
   • If a matter was already being dealt with by the UN Security Council under Chapter VII of the UN Charter, the court could not proceed with a prosecution unless the Council specifically decided otherwise.

In summary, the ILC Draft Statute envisaged a minimalist, relatively non-threatening court, designed to be politically acceptable and quick to establish.
5. From Minimalist Draft to Ambitious Rome Statute
However, events soon transformed expectations. The ILC Draft Statute was well received by many states. More importantly, the UN created two major ad hoc criminal tribunals:

• The International Criminal Tribunal for the former Yugoslavia (ICTY) in 1993, and
• The International Criminal Tribunal for Rwanda (ICTR) in 1994.

These tribunals helped build a political and diplomatic consensus in favor of a more robust court with clear substantive jurisdiction.
By the time states met in Rome in 1998 for the United Nations Diplomatic Conference of Plenipotentiaries on the Establishment of an International Criminal Court, the vision had shifted to a more substantial and powerful court. After intense negotiations, the Rome Statute of the International Criminal Court was adopted on 17 July 1998.
6. Entry into Force and Assembly of States Parties
The Rome Statute entered into force on 1 July 2002, after the deposit of the 60th instrument of ratification, acceptance, approval, or accession. There are now 122 States Parties.
These States Parties meet in the Assembly of States Parties (ASP):

• Each State Party has one vote.
• The ASP holds annual sessions and may convene special sessions “when circumstances so require.”
• Although the ASP is not an organ of the Court, it exercises important functions, including:
  • approving budgets,
  • adopting the Rules of Procedure and Evidence,
  • electing judges and the Prosecutor.

7. Effect on Non-States Parties (“Third States”)
The Rome Statute is a treaty. Under the terminology of the law of treaties, states not party to the Statute are “third states.”
The basic rule in Article 34 of the Vienna Convention on the Law of Treaties 1969 (VCLT)—sometimes summarized as pacta tertiis nec nocent nec prosunt—is that treaties do not create obligations or rights for third states without their consent.
However, customary international law goes further:
It is not only that treaties cannot create obligations or rights for third states without consent; they also cannot interfere with the existing legal rights of third states unless those states agree.
8. No Duty to Criminalize ICC Crimes Domestically
The Rome Statute does not require States Parties to:

• Enact all ICC crimes into their domestic criminal law, or
• Exercise jurisdiction on extraordinary bases, or
• Prosecute or extradite all suspects of ICC crimes.

The ICC regime is therefore not identical to treaty regimes that impose a strict “prosecute or extradite” (aut dedere aut judicare) obligation.


B. Basic Facts About the Court
1. Permanence and Comparison with Earlier Tribunals
The ICC is fundamentally different from earlier international criminal tribunals such as:

• The International Military Tribunal (IMT) at Nuremberg,
• The IMT for the Far East (Tokyo Tribunal),
• The ICTY,
• The ICTR,
• The Special Court for Sierra Leone (SCSL), and
• The Special Tribunal for Lebanon (STL).

All of those were ad hoc courts, created for specific situations and limited durations. The ICC, by contrast, was designed from the outset as a permanent international criminal court.
2. Relationship with the United Nations
The ICC is not an organ of the United Nations, nor is it part of the UN system. According to the ninth recital of the Rome Statute’s preamble, it is an independent institution “in relationship with the United Nations.”
Under Article 2 of the Rome Statute, the ICC’s relationship with the UN is governed by a Negotiated Relationship Agreement, approved by the Assembly of States Parties in 2004.
Despite its independence, the UN Security Council has significant powers under:

• Article 13(b) – to refer “situations” to the Court;
• Article 16 – to request the Court to defer investigations or prosecutions for renewable 12-month periods when this is deemed necessary for international peace and security.

3. Legal Personality and Capacity
The ICC is expressly granted international legal personality and such legal capacity as is necessary for carrying out its functions and fulfilling its purposes. This enables the Court to:

• Enter into agreements,
• Host its own staff and premises, and
• Operate in foreign states.

4. Seat, Territorial Reach, and Enforcement of Sentences
The ICC’s seat is in The Hague, the Netherlands, pursuant to a headquarters agreement with the Dutch government. However, the Court may also sit elsewhere whenever it considers such relocation desirable (for example, holding hearings closer to affected communities).
The ICC may exercise its functions:

• In the territory of any State Party, and
• In the territory of any other state by special agreement.

Prison sentences imposed by the ICC are served in states designated by the Court from a list of states that have expressed a willingness to accept convicted persons.
5. Principal Legal Instruments
The ICC’s legal framework is structured around three core instruments:

1. The Rome Statute – the constitutive treaty;
2. The Elements of Crimes – detailed elements for each crime;
3. The Rules of Procedure and Evidence (RPE).

The Elements of Crimes, adopted and amended by the Assembly of States Parties, are intended to assist the Court in interpreting and applying:

• Article 6 (Genocide),
• Article 7 (Crimes against humanity),
• Article 8 (War crimes),
• Article 8 bis (Crime of aggression).

Any amendments to the Elements of Crimes must be consistent with the Rome Statute.
Unlike the ad hoc tribunals (ICTY, ICTR, SCSL, STL), where judges adopted and amended the Rules of Procedure and Evidence, the ICC’s RPE are adopted and amended by the Assembly of States Parties. The judges may, in urgent cases, draft and apply provisional rules, which remain in force until the ASP confirms, amends, or rejects them.
6. Organs of the Court and Key Officials
The ICC has four principal organs:

1. The Presidency,
2. The Judicial Divisions (Appeals, Trial, Pre-Trial),
3. The Office of the Prosecutor (OTP),
4. The Registry.

Within the Judicial Divisions:

• All judges assigned to the Appeals Division constitute the Appeals Chamber.
• Three Trial Division judges constitute a Trial Chamber.
• A Pre-Trial Chamber may consist of:
  • three Pre-Trial judges, or
  • a single judge.

In February 2003, the Assembly of States Parties elected the first 18 judges of the ICC. Further elections have been held since.
Under Article 36(8)(a) of the Rome Statute, the composition of the Court’s bench must reflect:

• The main legal systems of the world,
• Equitable geographical representation,
• A fair balance of male and female judges.

In April 2003, the ASP elected Luis Moreno Ocampo (Argentina) as the first Chief Prosecutor. After his term ended in 2012, Fatou Bensouda (The Gambia), previously Deputy Prosecutor, was elected as his successor.
7. Due-Process Rights
The Rome Statute provides detailed protections for:

• Accused persons, and
• Persons under investigation.

The rights of the accused are closely modeled on Article 14 of the International Covenant on Civil and Political Rights (ICCPR) and include:

• Presumption of innocence,
• Right to a fair and public hearing,
• Right to counsel,
• Right to examine witnesses, and
• Protection against self-incrimination.

8. Protection and Participation of Victims
Among all international criminal court frameworks so far, the ICC’s is the most attentive to the interests of victims.
Like the earlier tribunals, the Rome Statute and the RPE provide for:

• Protection and support measures for both witnesses and victims, including through a Victims and Witnesses Unit within the Registry, similar to the units in the ICTY, ICTR, SCSL, and STL.

However, the ICC introduces several innovations:

1. Victim Participation
   When the personal interests of victims are affected, they may participate in proceedings—often through legal representatives—at appropriate stages and in a way that does not prejudice the rights of the accused or the fairness and impartiality of the trial.
2. Reparations
   Following a conviction, a Trial Chamber may order reparations to victims, including:
   • restitution,
   • compensation,
   • rehabilitation.

These orders may:

• be directed against the convicted person, or
• be implemented through the Trust Fund for Victims.

1. Trust Fund for Victims
   The Assembly of States Parties has established the Trust Fund for Victims (not an organ of the Court) for the benefit of:
   • victims of crimes within the jurisdiction of the Court, and
   • their families.

9. Funding of the ICC
The ICC is funded primarily through:

• Assessed contributions from States Parties (based on a scale similar to that of the UN), and
• Voluntary contributions from states, organizations, or individuals.

In addition, the UN General Assembly may approve funding, especially for expenses resulting from Security Council referrals.


C. The Procedural Essentials
1. A More Complex Route Than Ad Hoc Tribunals
The path by which a case comes before the ICC is far more complex than the relatively straightforward procedure used by earlier tribunals like the ICTY, ICTR, and SCSL, where the tribunal was given jurisdiction over a situation and could issue indictments directly once suspects were identified.
2. Three “Trigger” Mechanisms Under Article 13
For the ICC to exercise jurisdiction over genocide (Article 6), crimes against humanity (Article 7), and war crimes (Article 8), one of three “trigger” mechanisms under Article 13 must be activated:

1. State Party Referral (Article 13(a) and Article 14(1))
   • A State Party may refer a “situation” to the Prosecutor, alleging that one or more crimes within the Court’s jurisdiction appear to have been committed.
   • The referring state requests the Prosecutor to investigate for the purpose of determining whether specific individuals should be charged.
2. UN Security Council Referral (Article 13(b))
   • Acting under Chapter VII of the UN Charter, the Security Council may refer a situation to the Prosecutor.
   • This can cover conduct in any state, even if it is not a Party to the Rome Statute.
3. Prosecutor’s Proprio Motu Power (Article 13(c) and Article 15)
   • The Prosecutor may initiate an investigation on their own initiative, based on information on crimes within the Court’s jurisdiction.
   • However, the Prosecutor must:
     • first assess whether there is a reasonable basis to proceed, and
     • then seek authorization from a Pre-Trial Chamber.
   • Only if the Pre-Trial Chamber authorizes the investigation can it begin.

3. Preliminary Examinations (Article 53(1))
The Prosecutor is not obliged to open an investigation whenever a situation is referred or information is received.
Under Article 53(1), after evaluating the information and considering factors such as:

• jurisdiction,
• admissibility, and
• interests of justice,

the Prosecutor may conclude there is no reasonable basis to proceed and decide not to initiate an investigation.
This assessment phase is called a “preliminary examination.”
4. Decisions After Investigation (Article 53(2))
Even after an investigation has been opened—whether following a State Party referral, a Security Council referral, or proprio motu authorization—the Prosecutor is not obliged to bring charges.
Under Article 53(2), the Prosecutor may decide that there is insufficient basis for a prosecution for reasons including:

• lack of sufficient evidence,
• inadmissibility (e.g., genuine national proceedings), or
• the interests of justice.

If the Prosecutor decides to proceed, they must apply to a Pre-Trial Chamber for:

• a warrant of arrest, or
• a summons to appear for a named individual.

Once such an order is issued and the person is surrendered to the ICC, we then speak of a “case.”
5. Confirmation of Charges and Trial
When the individual arrives at the Court, they make an initial appearance before a Pre-Trial Chamber.
The Pre-Trial Chamber then holds a confirmation of charges hearing to determine whether there is sufficient evidence to establish “substantial grounds to believe” that the person committed each of the crimes charged.
If the Pre-Trial Chamber confirms the charges, the case proceeds to trial, possibly after further pre-trial motions and procedural steps.


D. Core Activity of the ICC to Date
1. Situations and Investigations
So far, the Prosecutor has received eight situation referrals:

• Six by States Parties, and
• Two by the UN Security Council.

Investigations have been opened in seven of these situations. In one situation, the Prosecutor decided not to open an investigation.
In addition, the Prosecutor has twice requested and obtained authorization to open an investigation proprio motu.
2. Arrest Warrants, Summonses, and Trials
The ICC has:

• Issued arrest warrants for 26 individuals on substantive charges (for core crimes), and
• Issued five more warrants for offences against the administration of justice (for example, interfering with witnesses).

It has also issued nine summonses for individuals to voluntarily appear before the Court (one of these summonses was later replaced by an arrest warrant).
So far:

• Three trials have been completed:
  • Two resulted in convictions,
  • One resulted in acquittal,
  • Appeals were pending in all three at the time described by the text.

Other developments include:

• Pre-Trial Chambers have declined to confirm charges against some suspects.
• The Prosecutor has withdrawn charges in at least one case.
• Some suspects for whom arrest warrants were issued remain at large.
• Three individuals died after warrants had been issued.
• One suspect is in custody in Libya.
• One case was terminated as inadmissible because genuine national proceedings were underway at the domestic level.

3. Ongoing and Closed Preliminary Examinations
In addition to situations in which investigations have been opened and two referred situations under continuing preliminary examination, the Prosecutor is currently:

• Conducting eight preliminary examinations, and
• Has closed three others after deciding not to proceed.

III. Ten Case Scenarios with Solutions (Applied to the Above Rules)
Each scenario shows how the ICC’s framework would operate in practice.


Scenario 1 – State Party Referral for Mass Atrocities
Facts:
State A, a State Party, experiences mass killings of civilians allegedly committed by rebel forces. Its domestic courts are weak and unable to prosecute. State A formally refers the situation to the ICC Prosecutor.
Legal Route (Solution):

1. State A’s referral triggers Article 13(a) and Article 14.
2. The Prosecutor conducts a preliminary examination (Article 53(1)) to assess jurisdiction, admissibility, and gravity.
3. If criteria are satisfied, the Prosecutor opens an investigation.
4. After gathering evidence, the Prosecutor may request arrest warrants from the Pre-Trial Chamber.
5. Once suspects are surrendered, charges are confirmed or rejected based on substantial grounds.

Key Principles:

• State Party referral, complementarity, and preliminary examination.

Scenario 2 – Security Council Referral in a Non-State Party
Facts:
Country B, not party to the Rome Statute, is engulfed in civil war. Reports allege widespread war crimes. The UN Security Council, acting under Chapter VII, refers the situation to the ICC.
Solution:

1. Article 13(b) activates ICC jurisdiction despite B not being a State Party.
2. The Prosecutor conducts a preliminary examination, then an investigation.
3. Arrest warrants are issued for key commanders.
4. Cooperation in arrest may depend on pressure from Security Council and States Parties.

Key Principles:

• Security Council referral extends ICC jurisdiction beyond membership; political support is crucial for enforcement.

Scenario 3 – Proprio Motu Investigation Based on NGO Submissions
Facts:
Several non-governmental organizations submit detailed reports of systematic torture in State C (a State Party). State C is unwilling to investigate. No referral is made.
Solution:

1. Prosecutor reviews information and conducts a preliminary examination.
2. Finding a reasonable basis, the Prosecutor seeks authorization from a Pre-Trial Chamber under Article 15.
3. If authorization is granted, a formal investigation begins.
4. Later, charges are brought and a confirmation of charges hearing takes place.

Key Principles:

• Proprio motu power, judicial control by Pre-Trial Chamber, complementarity.

Scenario 4 – Genuine National Proceedings and Inadmissibility
Facts:
State D is a State Party where senior military officers are accused of war crimes. The ICC Prosecutor is considering opening an investigation. However, State D launches serious domestic prosecutions in independent courts.
Solution:

1. During preliminary examination or admissibility assessment, the Prosecutor and/or the Court review whether domestic proceedings are genuine.
2. If they are, the case is inadmissible before the ICC under the complementarity principle.
3. The ICC will defer to State D’s justice system unless proceedings are later shown to be a sham.

Key Principles:

• Complementarity; the ICC as a court of last resort.

Scenario 5 – Refusal to Cooperate with Arrest
Facts:
State E, a State Party, receives a request to arrest a high-ranking official wanted by the ICC. The official is politically influential, and State E refuses to act.
Solution:

1. The Court may find State E in non-compliance and refer the matter to the Assembly of States Parties and possibly to the UN Security Council if a Security Council referral was involved.
2. Political and diplomatic pressure, including sanctions, may follow.
3. However, the ICC has no police force of its own; enforcement ultimately depends on States.

Key Principles:

• Enforcement deficits; reliance on state cooperation.

Scenario 6 – Victims Request Participation in Trial
Facts:
In a war crimes case, victims from State F wish to present their views and concerns before the ICC.
Solution:

1. Victims (or their lawyers) apply to participate under provisions on victims’ participation.
2. The Chamber decides whether their “personal interests” are affected and at what stages participation is appropriate.
3. Victims may submit written observations, attend hearings, and question witnesses through counsel, provided this is consistent with the rights of the accused.

Key Principles:

• Expanded role of victims; balancing participation with fair trial rights.

Scenario 7 – Reparations and the Trust Fund for Victims
Facts:
A commander from State G is convicted of crimes against humanity. Victims have suffered massive loss of property and trauma.
Solution:

1. The Trial Chamber considers reparations (restitution, compensation, rehabilitation).
2. It may order the convicted person to pay reparations directly and/or mandate that reparations be implemented in cooperation with the Trust Fund for Victims.
3. The Trust Fund may also use its own resources to assist victims and their families.

Key Principles:

• Reparations, restorative justice, victim-centered approach.

Scenario 8 – Case Terminated Due to National Proceedings
Facts:
An ICC investigation targets an official in State H. During the process, State H significantly reforms its judiciary and launches credible prosecutions against the same official.
Solution:

1. The ICC assesses whether these domestic proceedings are genuine and capable.
2. If so, the ICC may declare the case inadmissible and terminate it, as happened in at least one real case.
3. The ICC may still monitor the domestic process to ensure it is not a façade.

Key Principles:

• Dynamic complementarity, respect for improved domestic justice.

Scenario 9 – Non-State Party Cooperation by Special Agreement
Facts:
State I is not a Party to the Rome Statute but signs a special agreement with the ICC to host some hearings and allow Court operations on its territory.
Solution:

1. Under the Rome Statute and the Court’s practice, the ICC can sit outside The Hague where it considers it desirable.
2. By special agreement, it can exercise its powers and functions within State I’s territory.
3. This increases accessibility for local victims and witnesses.

Key Principles:

• Territorial flexibility; special agreements beyond States Parties.

Scenario 10 – Offences Against the Administration of Justice
Facts:
A witness in an ICC case is bribed and threatened by an associate of the accused to change testimony.
Solution:

1. The ICC may investigate and prosecute offences against the administration of justice (e.g., witness tampering).
2. The Court can issue arrest warrants for those responsible.
3. Protecting witnesses reinforces the integrity of the proceedings.

Key Principles:

• Protection of judicial process; integrity of evidence.

IV. Critical Analysis of the ICC Framework
1. Strengths

• Permanence and Stability
  The ICC is not limited to a specific conflict or time period. This provides continuity, institutional memory, and a growing body of jurisprudence.
• Comprehensive Legal Framework
  With the Rome Statute, Elements of Crimes, and detailed Rules of Procedure and Evidence, the ICC has a robust legal architecture.
• Victim-Centered Approach
  The ICC surpasses earlier tribunals by integrating victims:
  • They can participate in proceedings,
  • Receive reparations,
  • Benefit from the Trust Fund for Victims.
• Complementarity Principle
  The ICC does not replace national courts but supports them, acting only when states are unwilling or unable to prosecute.
• Checks and Balances
  The requirement of Pre-Trial Chamber authorization for proprio motu investigations and the multilayered appeal structure safeguard procedural fairness.

2. Weaknesses and Criticisms

• Dependence on State Cooperation
  Without its own enforcement agency, the ICC relies entirely on states to:
  • Arrest suspects,
  • Freeze assets,
  • Provide access to evidence and witnesses.
    Non-cooperation can paralyze cases.
• Security Council Politics
  The Security Council’s power to refer and defer cases can lead to accusations of selective justice or political bias, especially when permanent members are not themselves subject to ICC jurisdiction.
• Limited Membership
  Major powers (such as some permanent members of the Security Council) are not Parties, which:
  • Restricts jurisdiction,
  • Raises doubts about universality and fairness.
• Lengthy Proceedings
  ICC cases can take many years, which:
  • Strains resources,
  • Tests the patience of victims and affected communities,
  • Risks evidence becoming stale.
• Resource Constraints
  Funding remains finite, constraining the number of situations and cases that can be pursued.

3. Contemporary and Structural Challenges

• Balancing Peace and Justice
  Some argue that ICC indictments may complicate peace negotiations; others insist accountability is essential for sustainable peace.
• Regional Perceptions of Bias
  At times, regional organizations (notably within Africa) have criticized the Court for focusing disproportionately on cases from particular regions.
• Evolving Nature of International Crimes
  Emerging threats—such as cyber warfare or environmental destruction—raise questions about the future evolution of ICC jurisdiction.