As a native Georgian, I concur with Reaver. The North/South thing is a longstanding cultural divide in the US, and always has been. At the best of times, North and South have been two brothers that got nothing in common, and don't like eachother much, but they come together for holidays and family reunions and the like. At the worst, well, see the 1860s, which is basically two brothers fighting writ large.
The thing about that analogy, of course, is that while me and my brother might have a knock-down, drag out fight, if someone else attacks my brother, then they gotta deal with me, too. In other words, the only way you're going to see the UCAS and CAS reunite is if there is some overwhelming threat that forces them to set aside their differences. We're talking about something on the level of "the NAN decided to go and revisit that whole 'take back our land' thing", and we see the UCAS and CAS as common enemies against some or all of the NAN. The only other way would be if there was a third Crash, and it kicked the economy long and hard enough that the two countries were in similarly dire straits.
