Yeah, Sort of like Rome before Julius. You are insisting on a technical definition of “empire” as a political statement that does not correlate with the reality of American ascendance.
What I do insist on is that words have actual meanings, and that it's less than truthful to seriously abuse their definitions.
In this example, ancient Rome, 1900 France and Britain all had representative or republican governments at same time they were actual empires.
They also had voluntary alliances which were not part of their empires. And the difference is, for instance, Britain ruled over her empire, but did not rule over her alliances. Got is so far?
Yes, Britain may well have been the leader of some alliances, but there was no way for Britain to arbitrarily impose her will on her allies. They were all sovereign countries.
Today, unlike Britain in 1900, the US has NO EMPIRE, though we do have many alliances, and are usually the leader. But "leader" is no way the same as "ruler."
To be an "empire," you have to RULE. America has never RULED.