New Zealand and Australia would have the least fallout and background radiation and would have a thriving society during nuclear war.
Yeah, and we all know what this thriving society in Australia would look like
http://www.youtube.com/watch?v=Bmf-HCCZYOg
Of course, the whole world would be affected.
Radiation, extreme climate change with mass starvation as result , not just a crisis but the total breakdown of the global economy, fuel shortage , multiple resource shortages.
Just think what would happen with all the import Australia is depended on. No import, no export anymore from one day to the other. The economy would collapse in days.
Money would become worthless within weeks. Stores empty within months.
The surving countries would change drastically within months : Mass unrest, mass unemployment , riots, breakdown of governmental and economical structures, food shortages result in looting before you can say "my kid is hungry". Looting results in martial law before you can say "It wasnt me !"
Mad Max comes pretty close !
People in countries like Australia would survive (of course they would suffer mass deaths too, radiation, starvation,unrest, maybe even civil war in some cases)
But the countries themselves (government, laws , social structure etc.) would completely change forever. And not to the positive, be assured of that.
The "surviving" countries would develop backwards. Partially back to pre-industrial times. Some maybe even to almost medieval levels.
In case of the Fallout universe you also have to remember how close Australia is to China. For massive radioactive Fallout this is just a small journey.