We basically had that in form of the Imperial Romulan State. Donatra was cozying up to the Federation as much out of a sense of self preservation than anything else.
But the invariable reset button got pushed, presumably to make the Romulans a credible threat to the Federation once again, since all Trek fans are more familiar with them as opposed to the other Typhon powers.
Except that wasn't a reset button in any meaningful sense, because it ended up with the most genuinely moderate Romulan leader we've ever seen in power -- if you read Plagues of Night/Raise the Dawn, you saw that the Romulans have not just become hostile to the Federation again.
No, I haven't. Rough Beasts of the Empire was the last TP novel I read. So if you're saying the moderates prevailed, what was the literary purpose of Donatara's death and for that matter the entire IRS story arc again? It did get hand waved away rather conveniently.
The whole idea was that the exceptionally cutthroat and desperate nature of Romulan politics of the past few years created enough space for non-fanatics like Gell Kamemor to rise to power.