After the horrors of World War I, the Europeans powers pledged “never again.” Never again will they let competing national interests spark war. An international body — a “League of Nations,” to repeat Theodore Roosevelt’s famous phrase, would be made, to adjudicate and resolve conflicts between the nations. Throngs of crowds greeted the news, but in practice the League was less formidable: Russia, one of the European powers, was excluded, and the U.S., due to growing isolationist sentiment at home, refused to ratify it. The League was able to solve minor disputes, but dissolved in the face of wars started by its very signatories.

On this day, October 24, in 1945, following another World War, the successor to the League of Nations, the United Nations was founded. This one involved both Russia and the U.S., and its structural changes made a League reprisal unlikely.

The U.N. went further than its predecessor, establishing an actual International Labor organization and an International Court — long a dream of the League, but never realized. Its biggest challenge turned out to be when individual parties within the countries — sometimes egged on by the West or the Soviet Union, but just often on their own — began clamoring for freedom or for territorial control of their own.