UN Charter

The UN Charter was signed on June 26, 1945, at the conclusion of the United Nations Conference on International Organization in San Francisco. It entered into force on October 24, 1945, a date now celebrated annually as United Nations Day. The signing took place just weeks after Germany's surrender in World War II.

Fifty nations signed the Charter at the San Francisco Conference, with Poland signing shortly after to become the 51st founding member. The five permanent members of the Security Council—the United States, Soviet Union, United Kingdom, France, and China—were among the original signatories. Today, UN membership has grown to 193 member states.

The UN Charter is a binding multilateral treaty that establishes the United Nations as an international organization and defines its structure, including the Security Council and General Assembly. The Universal Declaration of Human Rights (UDHR), adopted by the General Assembly in 1948, is a non-binding declaration outlining fundamental individual rights. The Charter governs relations among states, while the UDHR focuses on protections for individuals.

Chapter VII of the UN Charter (Articles 39–51) authorizes the Security Council to take enforcement action, including military measures, to maintain or restore international peace and security. Article 42 specifically allows for action by air, sea, or land forces. This framework was invoked in resolutions authorizing interventions in Korea (1950) and the Gulf War (1991).