(The original article is
very good at providing a beginner's explanation of forex crises, and should be bookmarked for every time someone wants to talk about inflation)
> A country ought to feed its people
This is much harder than it sounds, not just for dense tiny countries like Singapore but for much of Western Europe. The UK hasn't been able to feed its population from native production only since before WW2. I see a Norwegian making the same point in this thread; the proportion of Norway's five million people that could be sustainably fed by fishing, reindeer hunting, and agriculture on the few flat bits of the country is probably very small.
> provide basic services like power and medical facilities on its own
Even harder. Only a superpower could begin to attempt having its own production chain for both of those. Everyone else has to buy from Siemens or Westinghouse, or Pfizer etc.
It sounds like you're saying that only superpowers or mega-countries should exist? Would the EU count as a self-sufficiency unit for this purpose?
(edit: Singapore imports 90% of its food! https://www.sfa.gov.sg/food-farming/singapore-food-supply/th... - not really suprising given that it's an island megacity with a population of 20,000 per square mile)