War is funny.
WWI started because everyone had to respect their treaties and join their allies into war.
Then WWII started because countries didn't join together from the start.
So, even if we learn from our past mistakes and avoid making them, with war, we can only do worse the next time.
That's right. For a variety of reasons the adoption of sedentary agriculture was a kind of trap that pulled almost the entire human race along with it. Now, the few remaining people living the kind of lives we evolved to live exist only in the world's most remote and inaccessible corners.