A while back, I heard a historian talking about World War II, and he said that the whole thing would never have broken out if the USA had maintained its original isolationist position during World War I. The chain of reasoning went like this:
- Originally, the United States saw the war as an exclusively European conflict, and stayed out of it.
- After the Zimmermann Telegram and ongoing German raids on US ships, the USA changed course and declared war.
- At the time this happened, the war in Europe had gotten bogged down and was essentially reaching a stalemate. American soldiers and materiel managed to turn the tide and turn it into a win for the Allies.
- Had the USA not entered the war, there would have been no advantage on either side. It would have been recognized as the stalemate it was fairly soon, and the war would have been resolved based on that reality.
- A different end to the war with no clear victor means no ruinous Treaty of Versailles devastating Germany's economy.
- No devastated German economy means no rise of the Nazi Party, no World War II, and no Holocaust.
The first two points are historical fact, and the last two are obviously correct, but I'm not so sure about the reasoning that connects them. That's what I'm wondering about: was the fighting in Europe building up to an inevitable stalemate before the USA joined in and tipped the scales? And if so, how likely is it that the political leaders of the nations involved would have been willing to recognize it as such and end the war under less devastating conditions than what actually happened?