, if she had occasionally closed her gates to let assimilation catch up with infiltration
not that I’m any expert on Rome, but I did read once that so wide an empire, without the bond of unity and nationalism instilling a feeling as part of one nation, instead of many parts just loosely associated with one nation and not feeling particularly obliged to defend any part not their own, was unsustainable. Same today as the islands feel towards America, half foot in the water and half out.
One of the curious parts of American history, if you go back to the 1700s and educational standards...the study of Rome was a standard topic for the self-taught American intellectuals. You can go all the way back to the late 1800s and still see a great deal of discussion over the history and battles.
The last fifty years? Almost nothing. If you open up a high school world history book....Rome rarely gets more than two to three pages of mention.