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'".
Charter of the United Nations
2. The non-permanent members of the Security Council shall be elected for a term of two years. In the first election of the non-permanent members after the increase of the membership of the Security Council from eleven to fifteen, two of the four additional members shall be chosen for a term of one year. A retiring member shall not be eligible for immediate re-election.