Charles Maier’s comparative study Among Empires: American Ascendancy and Its Predecessors reaches the waffly but accurate conclusion that the “United States reveals many, but not all - at least not yet - of the traits that distinguished empires.”

Early on, he makes the helpful distinction between “being” and “having” an empire: “States that are empires usually most of their territory according to one encompassing authoritarian regime, which may, however, allow enclaves of semi-autonomy. Nations that have empires rule their possessions abroad by authoritarian methods while they often govern their homelands by representative systems.”

Having rather than being an empire is not guarantee of greater freedom or justice. He notes that “One of the criteria of empires is precisely this discrepancy in the governance of component peoples. Ironically enough, the liberal states that had overseas empires often subjected these possessions to far more degrading and unfree conditions than those imposed on the contiguous peripheries of authoritarian states that were empires.”