I would have thought that the best equipped to deal with PO would be nations that still have large numbers of peasant farmers to fall back on.
The US having gone the furtherest down the oil road is the most in danger.
There are no back-up systems, none.
All this economics talk is quite vapid. Economics is not a deductive science.
All that maths is largely waffle built around the unsupport mental conjectures of a couple of late 19th Century French pundits.
It was never then or subsquently tested to see if it has anything to do with reality.
It is more like medieval scholastic theology than physics, which it tries hard to impersonate, in that it proceeds from unproven postulates into which it tries to force reality, rather then physics which observes reality and then devises theories to explain it.
Even of the US I suspect, the dangers of PO are more apparent than real.
True it has, like many other countries, got used to the ideal of constant economic growth, but historically speaking this has not been the norm. Quite often in the past economies have been stagnant or even gone backwards.
For people to make out that universal death and desolation will follow the moment economies don't grow is a little like some disgracefully spoiled aristocratic female declaring that she'll absolutely die if she doesn't lie on mink furs and eat ice-cream five times a day.
Most of the immediate problems of PO, when it hits, could be stayed (though not, of course solved) by systematic rationing of food and fuel and everyone keeping their nerve.
Of course this will involve disgarding the simple-minded if comforting Thatcher-Reaganite doctrines about free markets, but any nation that is prepared to die for their superstitions deserves all they get IMHO.
In the words of that greatest of Americans FDR: "There is nothing to fear but fear itself".
To which I would add: "and fear of fearing the fear of fear..."