What Is the Rome Statute and How Does the ICC Work?

The Rome Statute is the 1998 international treaty that created the International Criminal Court and gave it the authority to prosecute individuals for genocide, crimes against humanity, war crimes, and the crime of aggression. It was adopted on July 17, 1998, at a diplomatic conference in Rome and entered into force on July 1, 2002, after 60 countries deposited their ratifications with the UN Secretary-General.¹ As of 2025, 125 countries are states parties.² The treaty replaced the earlier pattern of ad hoc tribunals with a standing court that holds individuals, not states, accountable under one consistent legal framework.

What the Treaty Does

The statute does three things at once. It establishes the ICC as a permanent institution seated in The Hague. It defines, in detail, the crimes the court can try. And it sets the rules for how cases reach the court, how trials are conducted, and how member countries are obligated to cooperate.

The court is a court of last resort. It is not meant to replace national justice systems; it steps in only when those systems fail to act or cannot act. That boundary, known as complementarity, runs through the entire treaty.

The Four Crimes It Covers

The statute confines the court to four categories of crime, each with a precise definition that prosecutors must prove.

Genocide

Genocide means acts committed with the specific intent to destroy, in whole or in part, a national, ethnic, racial, or religious group. The statute lists five forms: killing members of the group, causing serious bodily or mental harm, deliberately inflicting conditions of life designed to physically destroy the group, preventing births, and forcibly transferring children out of the group.³ Intent is the hardest element to prove. Mass killing alone does not qualify without evidence that the perpetrator aimed to destroy the group itself.

Crimes Against Humanity

These are serious offenses committed as part of a widespread or systematic attack against a civilian population, carried out in line with a state or organizational policy. The listed acts include murder, extermination, enslavement, deportation, imprisonment, torture, sexual violence, persecution, enforced disappearance, and apartheid.³ A single murder is not a crime against humanity. The act has to be part of a broader pattern.

War Crimes

War crimes cover grave breaches of the 1949 Geneva Conventions and other serious violations of the laws of armed conflict. The category includes deliberately targeting civilians, torturing or mistreating prisoners, using prohibited weapons, attacking hospitals and humanitarian workers, and conscripting children under 15 into armed forces. Jurisdiction applies to both international conflicts and internal civil wars.³

The Crime of Aggression

Aggression is the planning, preparation, or execution of an act of armed force by one state against the sovereignty or territorial integrity of another, in clear violation of the UN Charter. It was defined by amendments adopted at a review conference in Kampala, Uganda, in 2010, and the court’s jurisdiction over it was activated on July 17, 2018.⁴ Only individuals able to direct a state’s military or political actions can be charged; it does not reach lower-ranking personnel.

Who the Court Can Reach

The ICC’s reach is not unlimited. The court can hear a case when the alleged crime occurred on the territory of a member country, or when the accused is a national of a member country. A non-member can also accept jurisdiction on a one-time basis for a specific situation.³ There is one notable exception: the UN Security Council can refer a situation under Chapter VII of the UN Charter, letting the ICC reach events in countries that never signed the treaty.⁵ That is how the court has pursued cases involving Sudan.

The court cannot prosecute crimes committed before July 1, 2002. For countries that joined later, jurisdiction reaches only crimes committed after that country’s own ratification date, unless the country separately accepted jurisdiction for an earlier period.³ The court also has no jurisdiction over anyone who was under 18 at the time of the alleged crime.⁶

Cases reach the prosecutor by three routes. A member country can refer a situation. The prosecutor can open an investigation independently, with authorization from a panel of judges. And the UN Security Council can refer a situation, which is the only path that bypasses the usual territorial and nationality requirements.³

No Immunity for Heads of State

Official capacity is irrelevant to criminal responsibility under the statute. A sitting head of state, government minister, member of parliament, or military commander has no exemption from prosecution, and official capacity cannot be used as a basis for a lighter sentence.³⁷⁸

When National Courts Handle It First

The ICC is designed as a backstop. Under the complementarity principle, a case is inadmissible before the ICC if a country with jurisdiction is already genuinely investigating or prosecuting it. The court moves only when national authorities are unwilling or unable to act.³

Unwillingness covers sham proceedings designed to shield the accused, or unjustified delay. Inability means the national judicial system has substantially collapsed and cannot realistically obtain the accused, gather evidence, or carry out proceedings. Every member country gets the first opportunity to handle its own cases. The ICC takes over only when that opportunity is wasted or absent.

Protections for the Accused

The statute builds in extensive protections for anyone brought before the court. Defendants are presumed innocent, and the prosecution carries the full burden of proving guilt beyond a reasonable doubt. The statute prohibits shifting that burden onto the defendant.⁹

The minimum guarantees for an accused person include:

Prompt, detailed notice of the charges in a language the accused fully understands.
Adequate time and facilities to prepare a defense and communicate privately with counsel.
Trial without undue delay.
The right to counsel of the accused’s choice, or appointed counsel at no cost for those who cannot afford one.
The right to examine prosecution witnesses and call defense witnesses under the same conditions.
Free interpretation and translation when proceedings are in a language the accused does not speak.
The right to remain silent, with silence not treated as evidence of guilt.

Penalties, Reparations, and Victim Participation

A person convicted by the ICC faces imprisonment for a specified term up to 30 years. Life imprisonment is available when the extreme gravity of the crime and the individual circumstances justify it. The court can also impose fines and order the forfeiture of property, assets, and proceeds derived from the crime, while protecting the rights of uninvolved third parties.³ The court does not impose the death penalty. That was a deliberate choice during the treaty negotiations.

Beyond punishment, the court can order reparations for victims. A convicted person can be directed to provide restitution, compensation, or rehabilitation. Where direct payment is not feasible, reparations can be channeled through the Trust Fund for Victims.³ Victims also have standing to participate in ICC proceedings when their personal interests are affected, with their views presented through legal representatives at appropriate stages.¹⁰

Who Is In, Who Is Out

The 125 states parties span every continent, with the largest regional blocs coming from Africa (33 states), Europe, and Latin America.² Several major powers have never joined. The United States signed the statute in 2000 but never ratified it, and Congress has repeatedly reaffirmed that the U.S. does not recognize the court’s jurisdiction.¹¹ China, Russia, India, and Israel are also non-parties.

Two countries have formally withdrawn after ratifying. Burundi’s withdrawal took effect in October 2017, and the Philippines’ withdrawal took effect in March 2019.¹² South Africa and The Gambia both announced withdrawals in 2016 but reversed course before their exits took effect. Withdrawal does not shield a country from jurisdiction over crimes committed while it was still a member.

The absence of major powers matters because the ICC has no police force. It depends entirely on member countries to arrest suspects, collect evidence, and enforce its orders. Every ratifying country agrees to cooperate fully with the court’s investigations and prosecutions, including complying with arrest warrants, surrendering named individuals, protecting witnesses, and tracing and freezing assets connected to crimes. When a member refuses, the court can formally find it in non-compliance and refer the matter to the Assembly of States Parties, or back to the Security Council if the Council originally referred the situation.³ In practice, enforcement is the court’s greatest weakness. Multiple member countries hosted Omar al-Bashir on state visits despite his outstanding arrest warrants, and the court’s findings of non-cooperation produced no meaningful consequence.

1
International Criminal Court. Rome Statute of the International Criminal Court
2
International Criminal Court. The States Parties to the Rome Statute
3
International Criminal Court. Rome Statute of the International Criminal Court
4
International Criminal Court. Assembly of States Parties Held a Three-Day Special Session on the Review of the Amendments on the Crime of Aggression
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International Criminal Court. How the Court Works
6
International Committee of the Red Cross. Rome Statute of the International Criminal Court, Article 26 – Exclusion of Jurisdiction Over Persons Under Eighteen
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International Criminal Court. Defendants
8
International Criminal Court. Netanyahu
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International Committee of the Red Cross. Rome Statute of the International Criminal Court, Article 66 – Presumption of Innocence
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International Committee of the Red Cross. Rome Statute of the International Criminal Court, Article 68
11
Congress.gov. Reaffirming That the United States Is Not a Party to the Rome Statute and Does Not Recognize the Jurisdiction of the International Criminal Court
12
United Nations. Rome Statute of the International Criminal Court – Status of Treaties