No, it's not been.
One thing to throw out: the Parthians, even while Hellenophile to a degree, are still primarily Persian-Aryan in culture, compared to all the Hellenic and Celtic states Rome had conquered till then and were vaguely-to-closely related to in linguistics and culture. If any territory is to be kept, it's probably what Trajan swiped-Armenia for sure (the traditional prize and hot potato in Roman-Parthian wars), and probably Mesopotamia/Assyria. Those were the most Greco-Roman-like areas and easiest to assimilate and hold down compared to beyond in Parthia/Persia proper: a hostile, alien populace with its own very long, very proud ethnic and imperial identity.
Remember Trajan did in fact take down the Parthian king of his time and had captured the capital Ctesiphon; he merely installed a new puppet king for the rest of Parthia on the Iranian Plateau. Caesar might be-I rather like to think he is-wily enough to do that and then focus on rebuilding and stablizing the rest of Rome with his Gallic, Mesopotamian, Armenian, and loyalist-Roman resources he now has.
One thing to throw out: the Parthians, even while Hellenophile to a degree, are still primarily Persian-Aryan in culture, compared to all the Hellenic and Celtic states Rome had conquered till then and were vaguely-to-closely related to in linguistics and culture. If any territory is to be kept, it's probably what Trajan swiped-Armenia for sure (the traditional prize and hot potato in Roman-Parthian wars), and probably Mesopotamia/Assyria. Those were the most Greco-Roman-like areas and easiest to assimilate and hold down compared to beyond in Parthia/Persia proper: a hostile, alien populace with its own very long, very proud ethnic and imperial identity.
Remember Trajan did in fact take down the Parthian king of his time and had captured the capital Ctesiphon; he merely installed a new puppet king for the rest of Parthia on the Iranian Plateau. Caesar might be-I rather like to think he is-wily enough to do that and then focus on rebuilding and stablizing the rest of Rome with his Gallic, Mesopotamian, Armenian, and loyalist-Roman resources he now has.