What is the International Criminal Court? How the ICC works

The International Criminal Court (ICC) is a permanent court in The Hague, in the Netherlands, that tries individual people, not countries, for four crimes: genocide, crimes against humanity, war crimes and the crime of aggression. It was created by a treaty, the Rome Statute of 1998, and began work in 2002. It is a court of last resort: it acts only when national courts are unwilling or unable to prosecute.

In short

• The ICC tries people, including heads of state, for the gravest crimes; it is not part of the UN and is a different body from the UN's own court.
• It can act only on crimes in a member state's territory or by a member state's citizens, unless the UN Security Council refers a situation to it.
• It has no police: suspects reach The Hague only if a state arrests and hands them over.

This note explains how the court works; it isn't legal advice and doesn't comment on any open case.

Why was the ICC created?

After the Nuremberg trials, the idea of a permanent international criminal court stalled for decades in the Cold War. The UN Security Council revived international justice in the 1990s by creating temporary tribunals for the former Yugoslavia, in 1993, and for Rwanda, in 1994. They showed that international trials could work, and also that setting up a new court for each conflict was slow and selective.

Delegates from 160 states met in Rome in the summer of 1998 to write a treaty for a permanent court. On 17 July 1998 they adopted the Rome Statute by 120 votes to 7, with 21 abstentions. The United States, China and Israel were among the countries that voted against. The statute came into force on 1 July 2002, after 60 states had ratified it, and the court can try only crimes committed from that date.

What crimes can the ICC try?

The Rome Statute gives the court jurisdiction over four crimes, defined in detail in the treaty and a companion document, the Elements of Crimes:

1. Genocide: acts intended to destroy a national, ethnic, racial or religious group, in whole or in part, in the words of the 1948 convention.
2. Crimes against humanity: murder, enslavement, deportation, torture, rape, persecution, enforced disappearance, apartheid and other acts committed as part of a widespread or systematic attack on civilians.
3. War crimes: grave breaches of the Geneva Conventions and other serious violations of the laws of war, such as attacking civilians, using child soldiers or targeting hospitals.
4. Aggression: planning or leading a state's use of armed force against another state in manifest violation of the UN Charter. Its definition was agreed at Kampala, Uganda, in 2010, and the court has had jurisdiction over it since 17 July 2018, with tighter limits than for the other three crimes.

Who is a member, and who isn't?

As of 5 November 2026, 125 states were parties to the Rome Statute, according to the UN Treaty Collection, most of Europe, Latin America and much of Africa among them. Several of the world's most powerful states are not: the United States, China, Russia and India have not joined, and neither have Israel, Turkey and much of the Middle East and Asia. The United States signed the treaty in 2000, then told the UN in 2002 that it did not intend to ratify it; Russia withdrew its signature in 2016. A state may leave by giving notice, which takes effect a year later: Burundi left in 2017 and the Philippines in 2019. According to the same record, six states, Niger, Burkina Faso, Mali, Venezuela, Chad and Nauru, gave notice between June and September 2026, to take effect a year later, while Hungary, which gave notice in 2025, took it back in May 2026.

When can the ICC take a case?

Two tests must both be met. First, jurisdiction. The court can act on crimes committed on a member state's territory, or by a member state's national anywhere. A non-member can also accept the court's jurisdiction by declaration. The UN Security Council can refer any situation to the court, member or not, as it did for Darfur, in Sudan, in 2005 and for Libya in 2011.

Second, admissibility, built on a principle called complementarity: national courts come first. Under Article 17, a case is inadmissible if a state with jurisdiction is genuinely investigating or prosecuting it, unless that state is "unwilling or unable genuinely" to do so. A case must also be grave enough. The court is designed to try the few people most responsible, not every soldier.

Cases reach the prosecutor in three ways: a member state refers a situation, the Security Council refers one, or the prosecutor opens an investigation on their own initiative, with permission from a panel of the court's judges. The Security Council can also pause an investigation or prosecution for 12 months at a time, renewably.

How does a case move through the court?

The court's own guide to how it works sets out the stages. Follow a hypothetical case of a militia commander accused of attacking villages in a member state:

1. Preliminary examination. The Office of the Prosecutor asks whether crimes within the court's jurisdiction were committed, whether they are grave enough, and whether national courts are genuinely dealing with them.
2. Investigation. If the answers point to the court, the prosecutor gathers evidence, from witnesses, documents, forensic work and video, and identifies suspects.
3. Arrest warrant or summons. Judges issue a warrant if there are reasonable grounds to believe the commander committed the crimes. The ICC relies on states to make the arrest and transfer the suspect.
4. Confirmation of charges. Once the suspect is in custody, three pre-trial judges hear the prosecution, the defense and lawyers for the victims, and decide, usually within 60 days, whether there is enough evidence for a trial. Judges may, in limited cases, hold this hearing without the suspect, but there are no trials in absentia: if no one arrests the suspect, the case cannot go to trial.
5. Trial. Three trial judges hear the case. The prosecution must prove guilt beyond reasonable doubt. Victims can take part through their own lawyers, which national courts often don't allow.
6. Verdict and sentence. The maximum sentence is 30 years in prison, or life in exceptional cases. There is no death penalty.
7. Appeal and reparations. Both sides may appeal. Judges can order reparations for victims, paid in part through the court's Trust Fund for Victims.

The court's first verdict, in 2012, convicted Thomas Lubanga Dyilo, a militia leader from the Democratic Republic of the Congo, of conscripting and using child soldiers; he was sentenced to 14 years. Step 3 is where many cases stall. Judges issued warrants for Sudan's then-president, Omar al-Bashir, in 2009 and 2010, the first for a sitting head of state; he travelled to several member states afterwards without being arrested, and in November 2026 the court's case page still described him as at large.

How is the ICC different from the International Court of Justice?

Both sit in The Hague, and their names are easily confused. They do different jobs.

	International Criminal Court (ICC)	International Court of Justice (ICJ)
Who it tries	Individuals	States
What kind of case	Criminal: genocide, crimes against humanity, war crimes, aggression	Disputes between states, under treaties and international law, and advisory opinions
Founded	2002, by the Rome Statute	1945, by the UN Charter
Relation to the UN	Independent treaty body, with a cooperation agreement	The UN's principal judicial organ
Who can bring a case	Member states, the Security Council, or the prosecutor	States that accept its jurisdiction; UN organs for opinions
Outcome	Conviction or acquittal, prison sentence, reparations	Judgment binding on the states in the case

A dispute over whether a country has breached the Genocide Convention goes to the International Court of Justice. A charge that a person committed genocide goes to the ICC or to a national court. Both can concern the same events.

Still argued

The ICC's record is argued from several sides. Supporters say it has made it possible to charge leaders who once had nothing to fear, that it gives victims a formal voice, and that its existence pushes states to prosecute crimes themselves. Critics in Africa long objected that most of its early cases concerned African countries, though several of those were referred by the African governments themselves. Others argue that it is too slow and expensive for the handful of verdicts it has reached, or, in the view of some non-member governments including the United States, that it should have no power over citizens of states that never joined. Defenders reply that a court that can reach only member states' crimes, plus Security Council referrals, has limited choice about where it works.

The ICC is one part of international law's answer to mass atrocity, alongside national courts, the United Nations and the treaties that define the crimes.

Check yourself

• Without looking back: name the four crimes the ICC can try, and say what complementarity means.
• Why can't the ICC try a crime committed inside a non-member state by that state's own citizens, unless something else happens first?
• What is the difference between the ICC and the International Court of Justice, in one sentence?

Sources

• Rome Statute of the International Criminal Court — International Criminal Court, 1998
• How the Court works — International Criminal Court
• Rome Statute of the International Criminal Court, status — United Nations Treaty Collection, 2026
• Al Bashir case — International Criminal Court
• The Court — International Court of Justice
• International Criminal Court — Wikipedia