The war that led to the establishment of the United Nations was World War II. The devastation caused by the war highlighted the need for a global organization aimed at promoting peace, security, and cooperation among nations. In 1945, representatives from various countries gathered in San Francisco to draft the UN Charter, which officially established the United Nations on October 24, 1945. This new organization sought to prevent the horrors of another global conflict by encouraging diplomatic dialogue and collaboration on various issues, ranging from human rights to humanitarian aid.