Yea I think the Fallout Verse basically has these huge blocs.
Canada, Australia, NZ had to look at the US instead of the UK which went with the European Commonwealth. The Middle East united (I take this to be a Pan-Arab thing, not some 'united ME which is just...no, and Turkey in the EC would allow them to rush in to help Israel).
India is a big power, maybe with a cuddly Iran, and of course fights China on the regular over Tibet. SEAsia was basically taken over by the Chinese.
Africa is where the Casablanca group, not the Monrovia group, won, though its probably dealing with the secessionist and greediness of the latter in numerous uprisings but they're winnin'. Maybe they get nuked by a South Africa Rogue State+Rhodesia that held out.
South America is harder to pin down, Pan-LatinAmericanism was more of a fringe thing even in the 19th century. Mexico is independent but they're big and had the oil to stay independent, so maybe the rest united in some sort of Pan-Latin Leftist bloc, drawing the nuclear aim of the USA, peeved after losing so many brush wars there.
And of course the USSR is still there as this Eurasian Socialist-Democratic Socialist giant. Reformed maybe, kept the Warsaw Pact somehow, but eh.