What is the ICJ? The international court of justice (ICJ) – not to be confused with the international criminal court (ICC), which tries individuals for war crimes – is the UN’s top court. Established in 1945, it is based in The Hague and rules on disputes between countries as well as giving advisory opinions. It has 15 judges – which will be expanded by an additional judge from each side in the Israel case – elected for nine-year terms by the UN general assembly and the security council. What is the case that South Africa has brought against Israel? South Africa has accused Israel of genocide in its campaign against Hamas in Gaza, saying among other things that it has the “specific intent … to destroy Palestinians in Gaza as a part of the broader Palestinian national, racial and ethnical group”. In its 84-page filing it also says Israel has failed to prevent genocide and failed to prosecute officials who have publicly incited genocide. While the court decides the case, South Africa also wants it to implement a provisional measure that would oblige Israel “not to engage in genocide, and to prevent and to punish genocide”. Temporary measures such as this are meant to prevent a situation from worsening while the case is decided. What is the legal definition of genocide? The genocide convention, which has been ratified by 153 countries including Israel, defines genocide as “any of the following acts committed with intent to destroy, in whole or in part, a national, ethnical, racial or religious group.” Those acts include killing members of the group, causing them serious bodily or mental harm, destroying their living conditions so as to bring about their destruction, preventing them from giving birth and forcibly transferring their children to other groups. The intent to carry out genocide is the “most difficult element to determine”, according to the UN definition. What has Israel said about the case? Immediately after the case was launched the Israeli foreign ministry spokesperson Lior Haiat issued a strong rebuke, calling the claims “baseless” and a “blood libel”, a reference to false accusations of murder and ritual sacrifice made against Jews. “Israel rejects with disgust the blood libel spread by South Africa in its application to the international court of justice,” Haiat said on X. “South Africa’s claim lacks both a factual and a legal basis, and constitutes a despicable and contemptuous exploitation of the court.” He also accused Pretoria of cooperating with a terrorist organisation in Hamas, and said Israel was “committed to international law”. How long will the case take? The full case, which is due to open on Thursday for two days of hearings, is likely to take years. However, an interim measure could be issued within weeks. In order to gain the temporary measure, South Africa does not need to prove that genocide has taken place. All it needs to prove is that the court would have jurisdiction at first glance, or “prima facie”, and that some of the acts it complains of – in this case including the death toll and forced displacement of Palestinians in Gaza – could fall under the genocide convention. Even if the court decides not to put in place an interim measure, it may still decide it has jurisdiction and proceed with the case. Is South Africa’s case supported by other countries? South Africa’s filing has been welcomed by the Organization of Islamic Cooperation, whose 57 members include many African and Muslim-majority countries such as Turkey and Malaysia, which have also made separate statements of support. What significance will a ruling have? The court’s ruling is final and cannot be appealed against. However, it cannot enforce its decisions and it is not clear that Israel would comply with it. But an adverse ruling would be detrimental to Israel’s reputation and set legal precedent.