The United Nations came into being on October 24, 1945. The Charter, signed by fifty nations at San Francisco that June, took effect when enough countries had ratified it, and the new organization began its work. The war it was born from had just ended.
The idea had been prepared during the war. The Allied powers, led by the United States, Britain, the Soviet Union, and China, had agreed on the need for a body to keep the peace, and the name United Nations had been used since 1942 for the alliance against the Axis. The peace would keep the name.
The structure was built on lessons from failure. The old League of Nations had collapsed in the 1930s, and the new body was given stronger tools, above all a Security Council of five permanent members with the power to act, and a General Assembly where every nation had a seat. The five powers kept a veto.
The hope was large. The preamble spoke of saving future generations from war, and the new body took up questions of peace, rights, and development, and it grew over the years to include nearly every nation on earth. The headquarters rose in New York. The glass tower went up.
The record is mixed. The United Nations has kept some peace and failed to prevent other wars, and the veto has often paralyzed it, and yet no better institution has replaced it. October 24, United Nations Day, marks both the hope of 1945 and the difficulty of the work.