The empires of Rome and America also mirror each other in one important way - they both became inherent systemic failures.
Both empires consumed beyond their means and came to depend upon ever increasing outside sources of energy to feed their cities, supply lines which they eventually could not control. In Rome's case the energy source was grain, and in Washington's case it is oil.
Rome was able to achieve what other city states at the time were incapable of, which was to support a metropolis of nearly 1 million people, at its peak. The usual peak population that a city could support itself was about 30,000, due to limits of grain supply in surrounding environs. In order to do this, Rome had to pillage virtually the entire known world of its resources, using its technologically superior army (sound familiar?) Without its vast pool of slaves and intensive farming techniques which spread across all the lands the Romans conquered, and its well-guarded supply lines from these peripheries back to Rome, the city could not have been sustained.
Once it had embarked on a program of urban expansion, it had sealed its doom. The larger the city, the more grain it needed. Its increasing militarism, totalitarianism and expansion were signs of its weakness, not its strength.
Eventually the diminishing returns of streched supply lines had their toll. Rome also suffered from a kind of 'peak soil' crisis due to its overintensive agriculture. All kind of social problems blew up. Slaves actually became too expensive to feed and house. With its currency inflated and its social fabric compromised it succumbed to a systemic collapse. After Rome was sacked, its population dropped drastically to the norm of about 30,000.
Now for those who reminisc about the glories of Rome, it must be recalled that it was largely an emprie of misery for those it encompassed, as this articles summarizes
http://www.classicsunveiled.com/romel/html/slavery.html
Its self-destructive practises of immorality, decadence, cruelty eventually lead to its decline of its social fabric.
There are those that know these details, but still fantasize about the glories of Rome, and welcome America's increasing parallels with it. Who cares if America's ballooning aggression will ultimately end in a painful collpase, who cares how many people suffer - Caeser achieved immortality, right? Isn't glory of the highest importance? This sad and infantile mentality not only flies in the face of all the world's wisdom on achieving happiness, but such a fantasy is impossible in the context of today. Whilst there are clearly many parallels between the Empire of 0007 AD and of 2007 Ad, one thing has changed and that is the increased flow of information.
Caeser was able to write extensive propaganda about his conquests in his 'De Bello Gallico' knowing that his words would be remembered. His enemies were illiterate, and so too were most of his soldiers. In an ocean of silence, his voice, his self-aggrandizing viewpoint, has indeed resounded through the ages. Such circumstances will never repeat themselves. Worldwide literacy is here to stay. Wars are not (usually) reported favourably anymore. Since Caesar, since explosive developments of communications technology, criticism of aggressive hegemonies has inevitably grown stronger and stronger by statesmen, populaces, historians. (cf British Empire, Third Reich, USSR). In the ocean of criticism and exposure that follows each act of American aggression, the war propagandists of today will be muted by history, after the empire's collapse. I hardly think, in the future multipolar world to come, that China and the Middle East will thank America, with any grovelling admiration, for the advent of the refinery or pocket calculator, as classicists today marvel at the aqueduct or stylus. There is no prospect of glory for the American empire.
America's only hope, for its own strength, for its own legacy, is to learn to live within its means. Sadly it is surely too late for that now.