So I know this is supposed to be sarcastic, but I actually think it was great. Wilson got into the war because he thought he could give them some advice, and his advice was brilliant. They didn't take it. Staying out of the war was also brilliant. It illustrated the stupidity of European politics, and it obviously made the USA the world's preeminent nation. The war was faught to see who was the most imporant nation, and it turns out it's us, and it would have also been us if we stayed totally out of it to the end. So really a pretty shockingly great outcome. Sometimes, one illustration is not enough, obviously. They needed a second one.
There is some degree of randomness of what kind of results you get, for sure. In World War II the sides could have been drawn differently, but they weren't.
Both wars, they said it was the public that wanted to stay out of it. Smart public.
So, about Nato: Since World war II, the USA was the only country holding NATO together. for some reasons it stayed together even though the UK had a communist government. NATO does 2 things:
1. It scares russia (not enough of course) and
2. It allows us to occupy Germany and tell them they can't have nukes. Germany has not attacked anybody since world war II. European constant self-descrtruction was stopped.
now, do we need that? It's a reasonable question, but of course nobody knows what people are going to do in the future. Like I said, sometimes you get random rewards. I don't have any idea why Putin does the stuff he does. He looks dumb to me. If they just end it over the USA election it wouldn't surprise me a bit.