Empire, as a noun, was value-free at the time the United States gained its independence. While its precise definition is elusive because of the problem of translation, it derived from the Latin imperium, which in English approximates the words rule and sovereignty. Hence its definition was functional or instrumental. Greeks used it to describe the relationship between the city-states that united to oppose the Persians (who also comprised an entity called an empire). But Athens exercised leadership over its fellow city-states; it did not really rule them.I am not trying to be difficult here, but I find this paragraph difficult to follow in a way that I rarely find (empirical) political science hard to understand. Why are we talking about imperium to describe the Athenians' relationship with the Delian League, when there are perfectly good words like hegemony to do that work instead? In what way was Athenian "leadership" different from Persian "rule"?
And why does the "Augustan" invention of bureaucracy (which, to readers of S.E. Finer's History of Government from the Earliest Times or, I don't know, Weber, would come as a surprise) that Zimmerman attributes to Michael Doyle's work two sentences later represent a phase change in "empire"? (Does that mean that we should call the "Augustan Threshold" the "Qin Revolution"?)
Some of my friends often claim they find historians hard to read because so many concepts are rendered informally or, worse, idiographically. I used to disagree with them. But the more I encounter academic historians seeking to make grand theoretical (or grand-theoretical) claims, the more I sympathize with their complaints.