The International Court of Justice, the top United Nations court for settling disputes between states, this week called on Russia to immediately stop its invasion of Ukraine, saying it was “profoundly concerned” about the use of force and dismissed its justification for military intervention.

Russia is unlikely to heed the order, but that does not mean that it does not matter. The ruling reinforces the foundational principle that rules govern relations among states, not raw power. It is up to governments to give that decision substance so that it is not just empty words.

Ukraine filed suit against Russia at the ICJ immediately after the invasion, asking the court to rule on the claim used as a pretext to invade and dismember the country. Moscow accused Ukraine of committing genocide in Luhansk and Donetsk, two regions in the eastern part of the country with large numbers of Russian-speakers.