Donald Kagan — American Historian

Donald Kagan is an American historian and classicist at Yale University specializing in ancient Greece, notable for his four-volume history of the Peloponnesian War. He formerly taught in the Department of History at Cornell University. At present, Kagan is considered among the foremost American scholars of Greek history... (wikipedia)

History had its own way of explaining things. The way historians explain things is by telling a story.
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.
You have to liberate yourself first from the prejudices of the world in which you live.
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.
Without history we are the prisoners of the accident of where and when we were born.