Chapter II of the United Nations Charter deals with membership of the United Nations organization. Membership is open to the original signatories and "all other peace-loving states which accept the obligations contained in the present Charter and, in the judgment of the Organization, are able and willing to carry out these obligations." A country can only be admitted to the UN after the UN General Assembly votes to do so upon the recommendation of the UN Security Council. The required assent of the permanent five (P5) members of the Security Council (People's Republic of China, France, Russian Federation, the United Kingdom, and the United States of America) no doubt accounts for why admission to membership in the UN is regarded as an important indicator of sovereignty and legitimate statehood (especially for microstates). On the other hand, some de facto-acknowledged independently-governed countries such as Taiwan have not been admitted to the UN due a veto by a P5 member. During the Cold War, the USA and the USSR did not allow the admission of countries from rival blocs for a while, but then began letting those countries join, which led to a period of great expansion of UN membership, especially as the number of sovereign countries increased due to colonies gaining independence.
Chapter II also provides for the suspension and expulsion of member countries from the UN by the UN General Assembly upon the recommendation of the UN Security Council, and for the restoration of rights to suspended members by the Security Council. Partly because of the procedure set out in this chapter, Taiwan has questioned the legality of United Nations General Assembly Resolution 2758 which declared that the People's Republic of China was the legitimate holder of the Chinese seat and that the Taiwanese delegation of Republic of China was questionably to be expelled forthwith and the entry of the People's Republic of China's Membership nor initially granting the recommendation by Republic of China in the Security Council before the General Assembly. In 2005, Israel called for the expulsion of Iran, apparently interpreting the latter's calls for the destruction of Israel as having "persistently violated the Principles contained in the present Charter" and thus meeting the Article 6 criteria for expulsion.