All comparisons between America's current place in the world and anything legitimately called an empire in the past reveal ignorance and confusion about any reasonable meaning of the concept empire, especially the comparison with the Roman Empire.
I can see that you are a true historian because you really always ought to ask that question about anybody at a different place or a different time: What's the same and what's different?
Throughout the human experience people have read history because they felt that it was a pleasure and that it was in some way instructive. The profession of professor of history has taken it in a very different direction.
We, to some degree, are like what we are because we inherited certain things from the Greeks and the Romans. One of them that's so striking is the whole area of politics.
