The 24 advisory opinions requested by the General Assembly, Security Council, or authorized specialized agencies likewise have dealt with a variety of matters. The court, on 16 October 1975, rendered an opinion in response to a request made by the General Assembly at its 1974 session. The question concerned Western Sahara, which was passing from Spanish administration. Morocco, Mauritania, and Algeria, all bordering states, took conflicting positions on ties of sovereignty that might have existed before the territory came under Spanish administration. The court concluded that no ties of territorial sovereignty between Western Sahara and the Kingdom of Morocco or the Mauritanian entity had existed. In the decolonization of the territory, therefore, the principle of self-determination through the free expression of the will of its people should apply in accordance with the relevant General Assembly resolution.
Another opinion concerned the question of whether the costs of the peacekeeping operations in the Middle East and the Congo could, within the scope of Article 17 of the Charter, be regarded as expenses of the organization to be financed by contributions of member states, as assessed by the General Assembly. In its opinion, issued on 20 July 1962, the court concluded that the expenses of both operations could be regarded as expenses of the UN within the meaning of Article 17 of the Charter.
Recent advisory opinions were rendered in July 1996 in response to a request made by the World Health Organization on the Legality of the Use by a State of Nuclear Weapons in Armed Conflict; and a request made by the UN General Assembly on the Legality or Use of Nuclear Weapons.