Falling apart

Civilizations fail, in turn, because their political classes lose the ability to inspire mimesis, and this happens in turn because members of the elite become so fixated on maintaining their own power and privilege that they stop doing an adequate job of addressing the problems facing their society. 

 As those problems spin further and further out of control, the political class loses the ability to inspire and settles instead for the ability to dominate. 

Outside the political class and its hangers-on, in turn, more and more of the population becomes what Toynbee calls an internal proletariat, an increasingly sullen underclass that still provides the political class with its cannon fodder and labor force but no longer sees anything to admire or emulate in those who order it around."

(From the Archdruid)