World War I and America's entry into it were the most disastrous events of the last 500 years. I think there is a good chance that historians in 500 years will look back and say that World War I is what killed Western Civilization.
The war itself was bad enough. It destroyed the old order that had brought in an unprecedented and in many ways, still unequaled time of peace, prosperity, and freedom in Europe. In 1914, a traveler could board a train in London, and in a couple days, get off in Moscow. In a week, he could be at the Pacific Ocean, all without ever having shown a passport.
But our entry into the war was disastrous. Without our entry, the war might have ended in a stalemate, or at least a more equal armistice. But, with us in the war, Germany knew she was beaten if she could not free up more troops. So, they put Lenin on a train and sent him to Russia to ferment revolution and knock Russia out of the war. It worked, but it still wasn't enough.
The Revolution spread to Germany and that coupled with its defeats on the western front forced it to seek armistice. Of course, it was really defeat and our refusal to follow through with what Wilson had promised led to even more disillusioned Germany and eventually Hitler and the NAZIs and WW II.
It is not an exaggeration to say that almost EVERY problem on the world stage today has its beginnings in that ridiculous war and its aftermath.
