This question comes up all the fucking time and I always answer it the same way:
the rest of the world does not matter in the Fallout franchise.
Why? Because parody of the aesthetic and ideals of the American "golden age" are integral parts of the franchise. Furthermore, everything people associate with
Fallout are exclusive to the American setting. Things like Vault-Tec, the Enclave, NCR, Super Mutants, etc. You strip all of this out and what do you end up with? A game that really isn't much like
Fallout at all. So there's no point to it. You might as well make a completley different franchise becuase at that point it basically is one.
The only place outside of America I can see a
Fallout game working is Canada, and that is becuase Canda was had been annexed by the US. So there would be an excuse to incorporate the things we associate with the
Fallout brand.
So as interesting as it might be to see apocalypse London, why make it a
Fallout game? Make a new franchise and go from there.
Volan said:
Otherwise, considering the war, it wouldn't make much sense to switch to another region - but perhaps the war affected other regions, and Vault-Tec branched out to surrounding allied countries, such as Europe or Australia and New Zealand.
Vault-Tec never branched outside of Canada and the US. In the
Fallout setting the US stopped giving a fuck about those countries long ago.