I'm reading Jared Diamond's Collapse: How Societies Choose to Fail or Survive at the moment. In the outline chapter he identifies five broad factors which can determine a society's fate: environmental damage, climate change, hostile neighbours, friendly trade partners, and how that society responds to its challenges. An early chapter examines Easter Island, which due to its lack of outside influences and isolation from the rest of Polynesian culture is perhaps the textbook example of a society killing itself off by degrading its environment (they cut down all their trees, which both decreased agricultural production due to erosion and reduced soil fertility, and meant they had no canoes, meaning much reduced access to seafood). But a sadder story is told in the next chapter, on Pitcairn and Henderson. These societies were not self-sufficient, but sustained by trade from the larger island of Mangareva; when that trade disappeared, Mangareva having made the same mistake as Easter and cut down all the trees which provided it with ocean-going canoes, so did the inhabitants of Pitcairn and Henderson. Not immediately - there is evidence that human habitation continued for up to a century after trade ceased - but by the time these islands were "discovered" by Europeans (1606 and 1790 respectively) they were empty. Diamond thinks that this should be a warning to us; globalisation has led to increasing economic interdependence, which allows us to offset the cost of degraded environments and sustain a well-fed, high-tech society through imports. But what happens if a vital part of the global economic system falls over?
Diamond uses the specific example of oil, and its fairly easy to see what the consequences of a sudden and sustained disruption of oil supplies (due to a nuclear exchange in the Middle East, for example) would be. The price would skyrocket, and in much of the world, transport would grind to a halt - resulting in a disruption of industrial production, economic recession, and possibly famine. If the disruption was long-lasting, societies would adapt, but more expensive transport would change patterns of industrial production and habitation; as in the nineteenth century, before we began using oil, factories would need to be closer to suppliers, and people closer to food sources.
What about total disruption? You'd need to look very hard to find a modern society as isolated and dependent on external trade as Henderson or Pitcairn was, but we can always do a though experiment. What would happen if New Zealand was completely cut off from the rest of the world? I think we'd actually do pretty well - we'd have to drop down to a 1900's or maybe 1940's level of existence, but we wouldn't die. And I think most western societies are probably in the same boat. The loss of imported fuel and raw materials would lead to vastly reduced standards of living, and the transition would be painful, but it wouldn't necessarily result in that society disappearing.
And OTOH, a painful transition is bad enough...
Following on from Diamond's point, if globalisation exposes us to risk, how can we manage it? Autarchy - self-sufficiency on a national level - may seem a tempting answer, but this throws out the benefits of interdependence along with the risks. I think a better solution is to use globalisation itself. Just as countries can ameliorate famine by working with others, we may be able to ameliorate other distributional disruptions (and on a global scale, famine is a distributional problem, not one of there not being enough food). Of course, self-interest and history will interfere with this, just as they interfere with other efforts to resolve global problems collectively - but I think its a lot better than each society trying to solve its own problems alone.