Agree that popular theories and analogies to Rome are almost always simplistic BUT
There are great lessons about history, war, leadership, morality, and human nature to be learned from Gibbons (The great historian, not the monkeys).
Compared to the height of Roman civilization, the world did really ‘go dark’ for quite some time, as de-facto warlords ruled small patches of territorry constantly warring amongst each other. It was not until the reneissance that the light of civilization truly emerged agian.
Tell that to our Congressional Democrats.
A lot of the civilized world did, however, go quite dark -
I found this fascinating -
http://www.amazon.com/Fall-Rome-End-Civilization/dp/0192807285