United Nations Security Council
Along with the five permanent members, the Security Council of the United Nations has temporary members that hold their seats on a rotating basis by geographic region. Non-permanent members may be involved in global security briefings. In its first two decades, the Security Council had six non-permanent members, the first of which were Australia, Brazil, Egypt, Mexico, the Netherlands, and Poland. In 1965, the number of non-permanent members was expanded to ten.
United Nations Security Council Resolution 984
The permanent members of the Council (all of which possessed nuclear weapons) had given security assurances to non-nuclear countries that were part of the NPT, the first time this had occurred. The Security Council recognised the need to give assurances to non-nuclear weapons states, and that the permanent members of the Council will act, according to relevant provisions in the Charter of the United Nations, in the event that a country is threatened or attacked with nuclear weapons. It also recognised that the permanent member states would bring such incidents to the attention of the Security Council. Assistance would be given in any case, with investigations and appropriate measures to settle disputes and restore international peace and security. Measures would also be taken to provide technical, medical, scientific or humanitarian assistance in response to any requests from an affected country. Additionally, appropriate measures would be recommended with regard to compensation after instances of aggression and the intention of some countries to provide immediate assistance to an affected country was welcomed by the Council.