Amendments to the United Nations Charter
Because Charter amendments require the consent of all five permanent members of the United Nations Security Council—defined in Article 23 of the Charter as "The Republic of China, France, the Union of Soviet Socialist Republics, the United Kingdom of Great Britain and Northern Ireland, and the United States"—it is impossible for other UN member states to force the permanent five to give up their Security Council 'veto power', by means of a Charter amendment. Many reformers have described this situation as a Catch-22. According to Global Policy Forum, "the P-5 are content with the present arrangements and oppose any changes that might dilute or challenge their power or expand their 'club.' China has already announced it will block permanent membership for Japan, and the United States has suggested that it will only support Council reform that commands an implausibly 'broad consensus'".
G4 nations
The UN currently has five permanent members with veto power in the Security Council: China, France, Russia, the United Kingdom, and the United States- comprising the victors of World War II. The G4 nations are regularly elected to two-year terms on the Security Council as non-permanent members by their respective regional groups: in the 24-year period from 1987 to 2010, Brazil and Japan were elected for five terms each, Germany for four terms (one term as West Germany and three terms as unified Germany) and India for four terms. Cumulatively, the G4 has spent 64 years on the Security Council since the UN's inception, with each country serving at least a decade. By comparison, the three permanent members of the Security Council who have maintained their seats since the UN's founding (France, the UK, and the US) have each accrued years of membership. The People's Republic of China has held its permanent seat for years, since it replaced the Republic of China in 1971, and Russia has held its permanent seat for years, since it replaced the Soviet Union in 1991.