Multilateral Courts: ICJ and ICC

The International Court of Justice

The ICJ, based in The Hague, is the principal judicial organ of the United Nations. It hears disputes between states — not individuals — on matters of international law. Its 15 judges are elected by the General Assembly and Security Council for nine-year terms. The ICJ has two functions: contentious cases (binding rulings in disputes between states that consent to jurisdiction) and advisory opinions (non-binding interpretations of international law requested by UN organs).

The ICJ has ruled on territorial disputes (Nicaragua v. Colombia on maritime boundaries), use of force (Nicaragua v. United States on the mining of harbors), genocide (Bosnia v. Serbia, Ukraine v. Russia), and environmental law. Its rulings are technically binding on the parties, but the Court has no enforcement mechanism. When the US refused to comply with the Nicaragua judgment in 1986, nothing happened. The ICJ's authority rests on legitimacy and reputational cost, not coercion.

The International Criminal Court

The ICC, also in The Hague, is fundamentally different from the ICJ. It prosecutes individuals — not states — for the most serious international crimes: genocide, crimes against humanity, war crimes, and the crime of aggression. Established by the Rome Statute in 2002, the ICC has 124 states parties. Major powers that have not joined include the United States, Russia, China, and India.

The ICC can exercise jurisdiction in three ways: when crimes occur on the territory of a state party, when the accused is a national of a state party, or when the UN Security Council refers a situation to the Court. The Security Council referral mechanism is how the ICC gained jurisdiction over events in Sudan (Darfur) and Libya, despite neither being a state party.

The ICC has faced persistent criticism. African states have argued it disproportionately targets African leaders. Its conviction rate has been slow — in its first two decades, the Court secured only a handful of convictions. And its inability to arrest suspects who remain in countries that do not cooperate limits its effectiveness. Nevertheless, the ICC's existence has shifted norms — leaders now know they could face prosecution, which may deter some atrocities even when the Court cannot directly intervene.

ICJ vs. ICC: Two Different Courts

Worked example — two cases arising from one war. Russia's invasion of Ukraine put both courts to work simultaneously, showing their division of labor. At the ICJ, Ukraine sued the Russian state under the Genocide Convention, and in March 2022 the Court ordered Russia to halt its military operations — an order Russia ignored, because the ICJ has no enforcer. At the ICC, the prosecutor pursued individual criminal responsibility and in March 2023 issued an arrest warrant for Vladimir Putin over the unlawful deportation of Ukrainian children. Putin then avoided ICC member states, even skipping a BRICS summit in South Africa that would have been legally obligated to detain him. One war, two courts: one judging the state, one judging the person — and both running into the same wall of enforcement.