I'll try and answer.
Our empire is spread around the world throughout 80 countries and territories, with an estimated 750 US military facilities. I'm certainly not the best suited to articulate it, but it's more an empire of financial hegemony than an empire of occupational enforcement.
The Roman Empire really only had two true laws. Don't revolt, and pay your taxes. Our only two true laws are don't F-with the petro dollar & and don't F-with our boats(shipping/trade). Any peoples under our hegemony have the right to self governance, within their states, as long as natural resources keep moving and shipping isn't impeded. F-up either of those too severely........, we'll squash that genocide, fascism, coup, dictator, tyrant, or whatever the 'current thing' is called.
I'm no FDR fan, but his(and his administrations) international diplomacy throughout WW2 was simply brilliant. A good bit of the foreign military facilities we occupy were obtained through lend l-lease. They also realized the economic advantages post war industrial manufacturing would provide.
MIC is the backbone and logistics holding it all up. Eisenhower tried to warn us about something to do with an outsized MIC and diminishing economic/resource advantages, though. We'll see.