The Dutch Ghost said:
Personally I think there should be a fixed history limit; the PA theme can only be handled for two, three centuries after the War, after that the newly established governments like the NCR and who knows what else have been busy rebuilding and reuniting the country, and that similar events take place over the rest of the world.
Speaking about "one could argue"...
We could argue about the credibility of large social structures being reconstructed as fast as they did in Fallout 2.
Chaos and anarchy after a nuclear war could be much more resilient than that.
People often bitch about New Reno being off-setting, but to me the greatest utter piece of bullcrap in the Fallout 2 setting is the NCR. I mean, no, it just doesn't make sense. The Fallout 1 world is an inhabited wasteland where the greatest form of social organization are gangs and some decadent sects, and then a republic spawns out of nowhere, on the very spot the lifeless craphole Shady Sands were ? This should get the palm of the most ridiculous setting twist in Fallout 2.
After all New Reno is much more fidel to the background of Fallout 1 : gangs fighting at each other to impose their law on a piece of desolated land and accumulate as much warranties of survival as they can