You might be interested in _War and Peace and War_, a theory of history focusing on social capital as a driving force, and in _The Fourth Turning_ -- which looks at changes over four-generation intervals, and which, written in 1997, made some surprisingly good predictions about the 2000s (the Aughts?). Both of these are in the tradition of Oswald Spengler's _Decline of the West_ and Arnold Toynbee's _A Study of History_; I'd recommend the abridged version of the latter, and I'd observe that if you can make it all the way through either of these you have more stamina than I do...
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