I was thinking about the whole "atompunk" scenario - you know the one I mean; the 1950s vision of the future, with nuclear powered cars and vacuum cleaners. While there are obvious issues with widespread nuclear power, I think the major reason that future didn't materialise is that petrochemical energy sources are just so much more convenient. After all, when those scenarios were confidently predicted, we didn't really know (a) how big the world's demand, with its population and prosperity rapidly growing, would be for cars, and (b) all the new oil reserves that would be discovered.
So what if we somehow cut at least the Western world off from oil - not wholly perhaps but enough to make it economically unviable? Would that deliver an atompunk setting (albeit probably in combination with hydroelectric and so on).
Of course the real question there is how. Something involving the Arab nations being in the Soviet sphere of influence somehow is probably needed, but you still need to consider things like West Africa, the North Sea, the Gulf of Mexico and so on. Any ideas for how we could get around that without ASBs?