In both cultures the people were the last to find out what was really going on. They had no understanding of how the various corrupt power centers were each selfishly vying against one another for dominance and wealth. People went about their daily routines unaware of the grief that lay just on the horizon. Eventually, after Rome split into two pieces it was ravages by the hordes of barbarians until all that is left of Rome is a city inside of the nation of Italy. Will Washington, DC one day be the capital of some emerging future east coast nation?
There is a distinct possibility for exactly the same reasons as the fall of the Roman empire - general public ignorance of what was really happening behind the scenes by greedy, power hungry tyrants who cared more for the possibility of being emperor than the survival of the nation. This is exactly what is occurring today with our secret ruling oligarchy. In America there are competing power centers all with daggers drawn ready to stab one another in the back. The Bush/Chaney power center is wounded by their failed coup attempt on the U.S. Congress in 2001. But they still have a minority of support from within the military and are therefore still dangerous. Fortunately, it appears a majority of the military elite have revolted against Bush/Chaney which is why these coup plotters have been blocked from the next phase of their operation which entailed exploding a nuke in a U.S. city, blaming it on Iran then nuking them before anybody could ask any questions.
So we still have that pesky Congress around and it appears the Republicans will be slaughtered in the fall elections. Even so we are certainly not out of the woods yet but there is cause for hope. We have the Internet. The Romans knew something was wrong only when they noticed a barbarian having his way with their Roman wife. The lucky ones got to be slaves for the new rulers. Today, there is a remote possibility that people feeling the pain of the tyrants' corruption on society will go to the Internet, read this simple explanation of what has happened, what could happen, then pass this link along until a wave of new consciousness arose and swept aside these scoundrels. But I'm storing food and water nonetheless.