Science fiction echoes this trend. The majority of the great epics of SF feature a galactic empire or ancient galactic republic with imperial properties, often an ancient and decaying one, and a young, vigorous, often exiled/outcast/rebel society which ends up recreating something very similar to that fallen empire from its ashes. Foundation, Dune, Heinlein's expanded universe, Star Wars, Star Trek, Battlestar Galactica, even the Doc Smith Lensman series: all recreate this pattern, often while inserting various elements of their own which either were the underlying causes of this cycle or which aimed to subvert/refocus it. Asimov went so far as to suggest that the cycle could be mathematically calculated with "psychohistory" and the future of a galactic society thereby predicted, possibly even averted.
Currently, the closest contender for hegemony would be the United States: and it too seems to be suffering from many of the same internal problems as brought down previous empires of its kind, such as stagnation and a certainty in its own moral superiority. Its legislative structure has become so bogged down by bureaucrats and lobbyists that it ends up accomplishing very little real positive internal change, such change tending to be lost within party politics and the safety of the way things are now. No doubt it is only coincidence that, every time the internal problems threaten to break out of control, an international incident always requires American soldiers?
When looking at fictional representations of the transition of even vaster galactic societies, there seems to be much focus on WWII Germany and Imperial Rome, even pre-Napoleonic France and Imperial Japan: but relatively very little on stagnant/collapsing republic or empire as a reflection of current conditions in the United States of America. Stagnation, rebellion, and evolution will tend to be spoken of as an abstract concept of the past rather than living issues of today: with rebellion the "white" side of a "black and white" issue. Ironically, in today's United States, rebellion (or revolution) is an idea which seems to live only in the American history. Although independence and revolution are very much a part of the American ideal, they seem to be accepted as an ideal whose time has passed, yet whose myth continues to thrive. Yet if suggestions of rebellion or revolution were raised today in the United States, how would most react?
How realistic are SF depictions of galactic republic and empire as allegories to our current global society? How far do they predict what is possible for the future?