I Am Not the Only One

To think that the partecipation of the USA in WWI wasn't such a great thing - in my words, no way that it "saved Europe's ass".

Possibly, American intervention caused even bigger problems later on. Tigerhawk:

3. The conclusion of World War I. My position is that our intervention was enormously costly both at the time and in history; by 1917, it did not actually matter to us whether Germany "won" at the expense of France, and it might have prevented both the rise of fascism and the success of the Soviet Union. My friend argues that Woodrow Wilson's meddling with the post-war settlement and our signing of the Treaty of Versailles was the real error, but I did not dig
deeply enough to understand why.

There are other interesting considerations on American foreign policy in the post and comments.