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.
When Edward Gibbon was writing about the fall of the Roman Empire in the late 18th century, he could argue that transportation hadn’t changed since ancient times. An imperial messenger on the Roman roads could get from Rome to London even faster in A.D. 100 than in 1750. But by 1850, and even more obviously today, all of that has changed.
The Papacy is not other than the Ghost of the deceased Roman Empire, sitting crowned upon the grave thereof.