Tacitus cites Calgacus, a scottish chief: “To ravage, to slaughter, to usurp under false titles, they call empire, and where they make a desert, they call it peace.” Rome did not win minds first and offer peace after, unless you immediately capitulated. If you didn’t immediately open your gates and submit, they first defeated you militarily, they butchered you and enslaved you. Then they gave your land to their veterans. And yes, several decades later you’d be “pacified”. From Corinth, to Gaul, to Jerusalem, to Dacia, just to name the ones that come to mind. It was not pretty.

And the expansion of Roman citizenship was not part of this process by the way. The first expansion followed the Social War and was only given to latin allies who had not forcefully demanded it. After that it trickled to the various client elites, until the edict of Caracalla, which came after the borders of the empire had been stable for about a century and it was arguably only done to allow the state to expand its tax base.