Look at all the great civilizations of the past, of which a few examples were Egypt, Greece, Rome in ancient times and the Mongol, Spanish, and British Empires more recently.
Without exception they reached a peak of fulfilling their aims and security, they achieved their purpose, they gained their goals and after doing so they had nothing worthwhile left to achieve and so turned to a life of hedonism and self destruction because there was nothing else left to do.
They reached a point where they had nothing left to achieve, and either fell apart from within or so weakened themselves that it became inevitable that they were conquered.
For sure America is breaking down, the parallels are plain to see, it currently resembles the “bread and circuses” stage of the Roman Empire with Trump reprising almost perfectly the corruption of the vain, cruel, capricious Caligula.
For sure the chaotic and useless EU of Europe won’t even reach that stage of greatness because it was founded already at the stage of hedonism and self-destruction.