United Nations
The United Nations is an international organization whose stated purposes are to maintain international peace and security, develop friendly relations among nations, achieve international cooperation, and serve as a centre for harmonizing the actions of nations of the Sol System.
The United Nations were founded in the wake of World War II to prevent future world wars from breaking out.
It became the default international cooperation within the Solar System in 2154, after Cislunar Space reopened to the rest of the solar system and several attempts of nations (Russian Federation, People's Republic of China, and others) attempted to 'reintegrate' 'rogue settlements', which had been forced to create local governments in the wake of the Beijing Impact and the Decades of Insulation, and had become independent nation states in their own right.
With nations recognising the former settlements of rival nations as independent, the Treaty of Geneva of 2154 recognised all existing nations as independent and offered them membership of the UN, extending the UN by 131 national seats of the Spacer Nations/Communities.