Throughout the history of civilization, empires rise and then fall.
Although the final stages of collapse can be rapid and violent, the actual collapse is gradual and occurs over years and decades. Because of gradualism, the collapse is usually imperceptible to the people. Only a handful observe the increasing oppression of the people and recognize it for what it is. And no one, it seems, learns from history.
There are several schools of thought as to what precipitates the end of empires. Two years ago Stratfor, the globalist think tank for multinational corporations, posited two of them. Citing the 1987 The Rise and Fall of the Great Powers, it pointed out that western powers since 1500 AD all fell after they were drawn into foreign entanglements that forced them to spend more of their wealth for wars. This created underinvestment in domestic needs, sending the country into an economic and social decline that emboldened more enemies. This created a cycle of more war and oppression.
In The Collapse of Complex Societies, author Joseph Tainter suggested that empires collapse following a loss of confidence in the ruling elite and traditional institutions. This idea was echoed in the book, Empire and Civilization by Niall Ferguson.
Do you see this in America today?
I believe both of these are true and would add another. There is a direct connection between debauching of the currency and the moral and social breakdown of society. America is experiencing all three simultaneously: engagement in multiple foreign entanglements (wars), loss of confidence in the ruling elite and traditional institutions and debasement of the currency through money printing.
The first is only made possible by money creation. Wars and foreign entanglements are always funded by fiat currency. The second is the result of the first. So the three causes go hand-in-hand.