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
The five permanent members of the Security Council were the victorious powers in World War II and have maintained the world's most powerful military forces ever since. They annually topped the list of countries with the highest military expenditures. In 2013, they spent over US$1 trillion combined on defence, accounting for over 55% of global military expenditures (the US alone accounting for over 35%). They are also among the world's largest arms exporters and are the only nations officially recognized as "nuclear-weapon states" under the Nuclear Non-Proliferation Treaty (NPT), though there are other states known or believed to be in possession of nuclear weapons.