i dont EVER want to see a mutated animal from the amazon jungle, i KNOW that i dont wanna see a mutated camel. trust me, america doesnt have many dangerous animals, why be anywhere else?

Alright I believe I know enough about the Fallout universe in my own right to add my own 2 cents to the question.
I think that one of the big huge points of all the DLCs released for Fallout 3 was to actually visually show us how [censored] up the world is now.
"Whats that? California nuked? thats a shame. D.C. hit too huh? damn. Wait a second what the hell is this these places are even worse than the ones that got cleaned out with the direct blast of nuclear assaults!"
Which sums up the message I see Bethesda as trying to give us. The entire biblical reference of Fallout and the Fallout universe is water as a source of life, most well known being Fallout 3s story line and all human civilization was built on the banks of the rivers, on the banks of life. Nuclear warfare has tainted the earth, the sky, and most symbolicly the water that is the source of all life, destroying or twisting all existing life beyond recognition. Look at the evidence.
Locations for the DLCs The Pitt and Point Lookout, the only two that actually take you somwhere really beyond the DC wastes, are almost entirely water based and because of this the corruption from radiation, and thus human malice, sin, and folly, they are far less than inhabitable in current conditions for one reason or another.
This being said, ALL WORLD LOCATIONS WOULD BE EFFECTED BY NUCLEAR BLOW UPS OF MAGNITUDE EVEN APPROACHING WHAT HAPPENED IN FALLOUT.
Winds carried trace particles from a single meltdown in Russia near the end of the Cold War to afflict Cows and grazing livestock after the unstable molecules had been exposed to local plants and fauna. Let alone anything that [censored] huge.

I'd say they stick with making the games in the US because many of the people buying the game will have a rough idea of what most major landmarks in the area should look like, thus making it interesting to see someone else's idea of how messed up those land marks would be. Capital wasteland was good, New Vegas was interesting...got to see the dam and the strip in post apoc. Certainly there are plenty of great landmarks in other countries as well, but how familure are we with them short of major ones such as the great wall of China or the pyramids?

True. If it was just between the Americans and Chinese, wouldn't one of the allied countries help out when on of their allies were nuked? I mean, if the UK, France or Australia wasn't nuked, they would send troops to the nuked countries ans help out the civies and everything. So, really, all nations were nuked, otherwise, 200 years prior to the Great War, America and China would be back on its feet.

I'm actually wondering how USSR is faring. Also, why didn't they side with neither US or China. We know that it existed during the Great War, because one of the Vault dwellers is the grand daughter of some soviet diplomat. I want to know more about their relations with other countries, technology etc.

There is also the fact that if any countries would have survived intact after the nuclear war, they would have already stepped in and annexed all this suddenly 'free' land. Or at least after the rads dropped enough to be save to go there.

Um...judging from Fallout lore and different things in real life...

When the U.S and China launched nukes at each other, ALL countries that were a nuclear wielding nation all launched their nukes at the allies enemies. For example if the U.S launches a nuke at China...Korea, Japan, and any other nuclear capable country in Asia and the Middle East would launch nukes at the U.S. Then the Europeans would be launching nukes at Asia. But NO, the whole world isn't nuked.

Parts of southern Africa should be mostly radiation free. Water would be still irradiated as the radiation would still linger in the oceans but there would be much less crap going on in Southern Africa and possibly South America. The Pacific Islands probably also have no real problems but that's debatable as some mutant fish would probably rule those islands. China would also be a very messed up place, much like the U.S but the Himalayas would be VERY MUCH untouched surprisingly. I won't go into detail why but just keep it that way. Just has to do with a natural mountain blockade stopping Super Mutants and other such things into the Himalayan basins and towns. Same with Switzerland.

This is this whole old nuclear war scenario, basically the southern hemisphere isnt a nuclear waepons platform like the northern hemisphere, yes i could see the nuclear countries, and since this is based on 1950's that would be limited to a few countries, so i can see the northern hemisphere being blown to hell, but i dont see the southern hemisphere specifically targeted for destruction. Now after reading the nuclear war scenarios, i can see that yes the southern hemisphere will be affected by the weather effects from the blasts, and how it says that the nation states didnt survive, well going through a worldwide cataclysm has a tendency to damage governments a little and the whole nuclear winter thing takes its toll on the enviroment, even though it still seems to have survived pretty well in fallout.

But i just dont see them basically nuking all of africa and south america and australia or indonesia or malaysia, or maybe there were a a few nukes left over and they said to hell with it lets just blow some stuff up what we got to lose.