THE HAGUE — The International Court of Justice issued an advisory opinion declaring that the right to strike is protected by a key labor treaty of the International Labor Organization. The ruling came from the court's 15 judges in The Hague, who were asked in 2023 by the International Labor Organization to settle an internal dispute over whether one of the ILO's conventions gives workers the right to strike.

The convention at the center of the case has been ratified by 158 countries and is incorporated into United Nations labor standards, guidelines from the Organization for Economic Cooperation and Development and international trade agreements. The United States is a member of the ILO but has not ratified the convention.

Advisory opinions of the court are not legally binding but carry weight in international law, and the decision could have a worldwide impact on labor regulations. Multiple U.N. agencies can ask the court to weigh in on legal questions and issue advisory opinions.

During hearings in October, the court heard from 18 countries and five international organizations, including the ILO, with other countries submitting written arguments. The majority of participants at the hearings favored the right to strike. The court is based in The Hague, Netherlands, and serves as the principal judicial organ of the United Nations.

The advisory opinion on the right to strike is not the first time the court has weighed in on a matter with broad international consequences. Last year, the court issued an advisory opinion stating that countries could be in violation of international law if they fail to take measures to protect the planet from climate change.