I'm sorry, Guy, but I never bought that bit about the Romulans not having warp drive at the time of the Romulan War: the Romulans were an empire stretching considerably great distances. For them, warp drive of some type had to exist, otherwise there would be no empire, as it would be hard to maintain control of however many systems said empire would have. I choose to believe that what was written in the episode was done early in the show before everything was completely nailed down (can't believe that Roddenberry wouldn't have at least got all details in writing before episodes were written, but there it is.)
Also, I don't believe that all the Romulans or the Klingons had were/was just only Warp 2, otherwise (again) there would be no empire. I believe that both of these political entities had Warp 5 or 6, so that they would be able to meet each other and become allies, and also to create and maintain their respective empires.