On November 29, 1943, as the Allies' primary leaders met in Tehran, Roosevelt described to Stalin his idea for the organization that would become the United Nations. The American president suggested that the active arm of the organization be "the Four Policemen": the U.S., USSR, UK, and China. Stalin agreed with much of the framework in principle, but asserted that China likely would not possess the strength after the war to assist. He also noted that the "Policemen" must hold a series of strong points, putting Germany and Japan at too much of a disadvantage to attempt military adventurism again. Roosevelt, eager to please his "friend," agreed with everything Stalin said.

That exchange might be considered the origin of the United Nations, one of the most famous bodies in the world, but the concept was already in existence in the form of its predecessor, the League of Nations. At the end of World War I, President Woodrow Wilson's pleas at the Paris Peace Conference relied on his Fourteen Points, which included the establishment of a League of Nations, but while his points were mostly popular amongst Americans and Europeans alike, leaders at the conference largely discarded them and favored different approaches. British leaders saw their singular aim as the maintenance of British colonial possessions. France, meanwhile, only wanted to ensure that Germany was weakened and unable to wage war again, and it too had colonial interests abroad that it hoped to maintain. Britain and France thus saw eye-to-eye, with both wanting a weaker Germany and both wanting to maintain their colonies. Wilson, however, wanted both countries to rid themselves of their colonies, and he wanted Germany to maintain its self-determination and right to self-defense. Wilson totally opposed the "war guilt" clause, which blamed the war on Germany.