The ICJ settles disputes between countries. It was originally set up as the first world court by the League of Nations, in the hope that "law and justice" would trump "diplomatic expediency".
Judges on the first world court were careful to avoid overstepping their powers. Oda Yorozu, one of the first judges, thought the very idea of world peace was an impractical dream. In 1923 the League of Nations asked for an advisory opinion on a border dispute between Finland and Russia, which was not a member of the league or the court. The court refused, saying that disputes between countries could be adjudicated only with the consent of both.
Much of that early caution has been abandoned. The United Nations has repeatedly asked the ICJ to give advisory opinions on areas outside its competence, such as climate change. Critics say this asks judges to answer questions that are political (such as how much to spend on mitigating climate change) or diplomatic (when and how to stop a war), reflecting a failure of diplomacy and other international political institutions to resolve disputes.
The court threw out an urgent request by Sudan to order the UAE to stop supporting a genocidal militia in Darfur. The UAE had signed the Genocide Convention of 1948 on the condition that it would apply only to others, opting out of the ICJ's automatic jurisdiction.
The ICJ has never been busier. Cases include South Africa's genocide claim against Israel and a wide range of other suits. The court's workload stands in contrast to the declining fortunes of the International Criminal Court, its neighbour in The Hague.
The ICJ has issued helpful rulings in territorial disputes where both sides agreed to be bound by it.
Sometimes I simply feel that the whole world is a cigarette and I'm the only ashtray.