I don’t think you’d like to be ANYBODY in that scenario.
It would suck to be an Aztlanista separatist - the UN will abuse you, Americans will kill you and, your own provisional government is full of vicious backstabbing psychopaths (think Cuba or the USSR after their revolutions)...
It would suck to be the UN - Americans will kill you if they can, and you’re working with sneaky, smelly, corrupt, Aztlanistas. The Americans are crippling your supply lines, and trying to destroy or boobytrap any supplies you might forage.
It would suck to be an American or NG - the Federales ain’t supportin’ you, ammo is running out, food is running out and essential services are disrupted and there is no central command to help you kill the bastards. And where is your family and how are you going to keep them fed?
It would suck to be the Federales - you’re being prevented from doing the right thing by elements within your own government and there is no (legal) way to get rid of them; also you have to worry about budget and political issues.
IT would pretty much suck, period. Of course, that is what “adventure” is - somebody else, comfortably far away in space and/or time, having a hard time of it... Just ask Bilbo Baggins!