It's commonplace to identify America today with the Roman Empire.
I've just finished Robin Lane Fox's wonderful "The Classical World: An Epic History from Homer to Hadrian". Fox points out that a number of 'first citizen's (as Emperors called themselves for the fig-leaf of legality) were assassinated in the name of freedom - Julius Caesar, Caligula and many subsequent. In each case it proved politically impossible to restore the Republic. Augustus proved the point by dallying away from Rome until the senators called him back in desperation to sort out disputes.
Fox is less analytic as to why this might have been the case, but it was surely a function of the lack of senatorial legitimacy amongst the plebs, and perhaps more importantly, the legions, each of which needed a champion to secure their wages, and colonisation land once they had finished military service.
In a patronal society (one we would today call deeply corrupt) a hierarchy centred around one individual seemed to be optimal in managing power and resource relationships.
Which major power does this sound most like today? Russia.
