Explainer: What is the International Court of Justice and why does it matter?

The profile of the International Court of Justice (ICJ) was raised in January, following South Africa’s decision to bring proceedings against Israel for violating its obligations under the Genocide Convention. Here is a primer on the ICJ, and what it does.

What is the ICJ for, and how does it work?

The ICJ, which is situated in the Peace Palace in The Hague, a city in The Netherlands, was established in 1945 as a way of settling disputes between countries. The Court also provides advisory opinions on legal questions that have been referred to it by other authorised UN organs.

Widely known as the ‘World Court’, the ICJ is one of the six “principal organs” of the United Nations, on the same footing as the General Assembly, the Security Council, the Economic and Social Council (ECOSOC), the Trusteeship Council and the Secretariat, and the only one that is not located in New York.

Unlike the Court of Justice of the European Union, the ICJ is not a supreme court to which national courts can turn: it can only hear a dispute when requested to do so by one or more States.

The Court is composed of 15 judges, all of whom are elected to nine-year terms of office by the UN General Assembly and Security Council. Elections are held every three years for one-third of the seats, and retiring judges may be re-elected. The Members of the Court do not represent their governments but are independent magistrates, and there is only ever one judge of any nationality on the Court.

Cases open with the parties filing and exchanging pleadings containing a detailed statement of the points of fact and of law on which each party relies, and an oral phase consisting of public hearings at which agents and counsel address the Court.

The countries involved appoint an agent to plead their case, someone who has the same rights and obligations as a solicitor in a national court. Occasionally, a leading politician may defend their country, as in the 2020 Gambia/ Myanmar case.

After this stage, the judges deliberate in camera (in private, behind closed doors), and then the Court delivers its verdict. The length of time this takes can be anything from a few weeks to several years.

Why is the ICJ important?

The ICJ is the only international court that settles disputes between the 193 UN Member States. This means that it makes an important contribution to global peace and security, providing a way for countries to resolve issues without resorting to conflict.

What kind of cases are brought before the Court?

The Court can rule on two types of cases: “contentious cases” are legal disputes between States; and “advisory proceedings” are requests for advisory opinions on legal questions referred to it by United Nations organs and certain specialized agencies.

The case brought by South Africa against Israel on 29 December last year is the first time a contentious case has been brought against Israel at the ICJ (a 2004 advisory opinion found that the construction of the wall built by Israel in the Occupied Palestinian Territory, including in and around East Jerusalem, and its associated regime, is contrary to international law).

Ronald Lamola (centre), Minister of Justice of South Africa, and Vusimuzi Madonsela (right), South African Ambassador to the Netherlands, at the International Court of Justice (ICJ) prior to the hearing of the genocide case against Israel through South Africa. (Photo by REMKO DE WAAL / ANP MAG / ANP via AFP)

South Africa contends that “acts and omissions by Israel...are genocidal in character, as they are committed with the requisite specific intent...to destroy Palestinians in Gaza as a part of the broader Palestinian national, racial and ethnical group”.

South Africa seeks to find the Court’s jurisdiction on the 1948 UN Genocide Convention, to which both countries are signatories. Israel rejects the allegations.

Another relatively recent case that gained international attention involved a ruling against Myanmar in January 2020, ordering the country to protect its minority Rohingya population and the destruction of evidence related to genocide allegations.

That case, which was brought by The Gambia, was notable for the appearance of Aung San Suu Kyi, then the de facto leader of Myanmar, making an appearance at The Hague to defend her country.

As for “advisory proceedings” " on 20 January 2023, the General Assembly requested an advisory opinion from the Court on “Israeli practices affecting the human rights of the Palestinian people in the Occupied Palestinian Territory, including East Jerusalem”.

In March 2023, the UN General Assembly adopted a resolution to ask the court to deliver an advisory opinion on the obligations of States in respect of climate change, with most speakers in the resulting debate hailing the move as a milestone in their decades-long struggle for climate justice. Both advisory proceedings are ongoing.

Who can bring a case to the Court?

Any Member State can bring a case against any other Member State, whether or not they are directly in conflict when the common interest of the international community is at stake.

Aung San Suu Kyi appears at the UN International Court of Justice (ICJ) on 11 December 2019. (Photo: ICJ/Frank van Beek)

In the case of The Gambia v Myanmar for example, The Gambia was not directly concerned by the genocide allegations levelled against Myanmar, but that did not preclude the country from bringing the action, on behalf of the Organisation of Islamic Cooperation.

What are the consequences of a Court ruling?

The rulings of the ICJ are final and there is no possibility of appeal.

It is up to the States concerned to apply the decisions of the Court in their national jurisdictions, and, in most cases,they honour their obligations under international law and comply.

If a country fails to perform the obligations incumbent upon it under a judgment, the only remaining recourse is to turn to the Security Council which can vote on a resolution, per the UN Charter. This happened in a case brought by Nicaragua against the United States in 1984, demanding reparations for the US support for Contra rebels.

The ICJ ruled in Nicaragua’s favour, but the US refused to accept the finding. Nicaragua then took the matter to the Security Council, where a relevant resolution was vetoed by the United States.

How is the ICJ different from the ICC?

There is frequent confusion between the International Criminal Court (ICC) and the International Court of Justice (ICJ).

The simplest way to explain the difference is that ICJ cases involve countries, and the ICC is a criminal court, which brings cases against individuals for war crimes or crimes against humanity.

Also, whilst the ICJ is an organ of the United Nations, the ICC is legally independent of the UN, (although it is endorsed by the General Assembly).

While not all 193 UN Member States are parties to the ICC, it can launch investigations and open cases related to alleged crimes committed on the territory or by a national of a State party to the ICC or of a State that has accepted its jurisdiction.

Cases have been heard and decisions rendered on a range of violations, from using rape as a weapon of war to conscripting children as combatants.