
was never super clear on the political landscape of either the GTA or the GTVA, not that I've read anyway. The issue is that canonically you are a fighter/bomber pilot in the navy both times. Your job isn't to make, enact or interpret policy. You fly where they tell you and shoot who they tell you. It thankfully is shivans more often than not in the two games that are the only official material we have to work from.
In my mind, and most everyone else it seems, the individual colony systems are put into the position of individual nations. So travel between systems, while relatively quick given the distances, is akin to "going abroad" to Asia, America or Europe back in the 20's and 30's when international flight was a dream and you were weeks away from Bangkok or Paris or New York City.
So what I would think that the GTA would be appropriate given the organizational limitations of being that far apart would be an loose affiliation of trading partners that contribute money, materiel and personnel to a communal military. With the coming of the Shivans, I don't think much would change save the amount spent on defense.