In the aftermath of World War I, much of the world signed on to an organization designed to make it impossible to enter another catastrophic war. It was the League of Nations, an ambitious entity established 100 years ago this month that asked its member states to ensure one another’s security and national interests. But though it came into being after an American president’s call to action, the United States itself was never a member—and the League was destined to fail.

Both the League’s beginnings and its disastrous end began in the depths of World War I, a conflict that pitted nations against one another long after the armistice. In January 1918, President Woodrow Wilson laid out an idealistic 14-point