Link below is to a relevant work I used in another life to teach young "field grades" about the cycle of empires. MB is probably familiar with this one. Along with Aristotle’s bits on the cycles of life: the 80 year cycle of men from founders (hard men who make things better), heirs (sons of founders who remember hard times), imitators (spoiled grandsons who have never known anything but comfort and disregard Grandfather’s strange stories), and the decadent generation (those who haven’t heard the stories, studied only politically correct revisionist history in public school and know nothing about reality, but only self indulgence). Cycles of nature and empires. Glubb captures succinctly in his attempt to explain the decline of his own empire.
http://people.uncw.edu/kozloffm/glubb.pdf