Theodore Roosevelt was the first to use the term “League of Nations,” his vision of an international community making decisions and resolving conflicts jointly. When it was formed, however, Roosevelt had to reject an invitation to join it because of America’s isolationism. The vestiges of that isolationism evaporated after WW II with the rise of the Soviet Union, a foe that Winston Churchill described as more insidious and formidable than the one they’d just defeated. This time there could be no isolation: the United States had to cooperate with Russia wherever possible, and check its power militarily wherever necessary. Both had to be accomplished in concert with other nations in an organization that replaced the League.

On this day, December 4, in 1945, by a vote of 65 to 7 the Senate approved U.S. participation in the League of Nations.

Hiding in the final tally was the fierce debates in Congress about the meaning or obligations of the U.S. within the organization. Some lawmakers worried American troops would be committed to foreign theaters of war where there was no U.S. interest. A bill introduced to force the president to seek Congressional approval before deploying troops was soundly defeated. In fact it would be the United States leading the first large-scale U.N. armed intervention – in protecting South Korea against the Communist North.