There is a theory that this is what happens when you have several generations live their lives without seeing a major war or crisis, and feeling its results firsthand. Presumably, that's when people, and societies as a whole, get too "cocky" and less compromising, because they don't fear the consequences enough.
Yeah, I think after a few generations of stability, when the last survivors of the last major calamity leave power, people start believing that this time is different, we've moved past war, without realizing that humans haven't fundamentally changed.
