For what it’s worth, Peter J. Leithart writes in Defending Constantine: The Twilight of an Empire and the Dawn of Civilization about the Roman way of war:
The Roman Empire did not have a grand strategy in the sense that moderns think of it. The Romans lacked the technology in both cartography and communications. There is something to be said for the thesis that Rome’s empire was an “unexpected” empire that expanded through a ripple of defensive alliances. Security in the negative sense of safe roads, unpillaged fields, untransgressed borders does not, however, explain Roman imperial behavior. As Augustine knew, what guided foreign policy and imperial expansion was Roman love for honor, philotimia, which expressed itself in a lust for domination (libidio dominandi). Romans gained glory and honor by conquest, and by the titles and honors paid to conquerors back home. When a rival treated Rome with mockery, that insult needed to be avenged, with clemency if possible, viciously if necessary. Earlier in [the Emperor] Domitian’s reign, Nasamones massacred Romans and plundered the camp of Flaccus, but then drank themselves to death on the spoils. This gave Flaccus the opportunity to “annihilate them, even destroying all the non-combatants.” The same Domitian whose helpless Dacian war we have noted was “elated” and boasted to the Senate, “I have forbidden the Nasmones [sic] to exist.” Terror kept barbarian pride in check; the sacrifice of barbarians and rebels maintained Roman honor.
This was, to the Romans sense, a defensive posture. Romans reasoned, If the barbarians get uppity, they might attack. To be safe, we need to make sure they never get uppity. Shock and awe keep them in their place, and any sign of weakness only encourages them. [Italics in original.] Roman imperial policy may be described as a pursuit of “security” so long as it is understood that security meant honor. Virgil had written that the Roman Empire existed to subdue pride, superbia. That was true, but Romans came to define superbia as any opposition to Rome.
Make whatever connections to our time and place that strike your fancy.