The World Health Organization requested the opinion on 3 September 1993, but it was initially refused because the WHO was acting outside its legal capacity ("ultra vires"). So the United Nations General Assembly requested another opinion in December 1994, accepted by the Court in January 1995. As well as determining the illegality of nuclear weapon use, the court discussed the proper role of international judicial bodies, the ICJ's advisory function, international humanitarian law ("jus in bello"), and rules governing the use of force ("jus ad bellum"). It explored the status of ""Lotus" approach", and employed the concept of "non liquet". There were also strategic questions such as the legality of the practice of nuclear deterrence or the meaning of Article VI of the 1968 Treaty on the Non-Proliferation of Nuclear Weapons.