Most bases in germany have been closed now, and they were there for so long to help guard against invasion by the soviets not to suppress the germans or force the US views on them or collect empirical tax, like the romans basically did.
That doesn't take away the core of your thoughts though, I'm just correcting that error in an argument used.
And the romans of course introduced a lot of advancements in many areas they conquered, baths, aqueducts, roads, organization, and the US only seem to take care of themselves, so that's not very empire-like in comparison. There's a thought in many americans and politicians that the US is an empire though, and has some special right to push the rest of the world around, but in the US's defense you must say that many other countries encourage that thinking too by acting like it is true and being subservient to the US in the political arena (little joke there to use a familiar roman term 'arena').