Imagine being in the government that oversees a self-sufficient population, everyone producing to meet their needs. Granted no one can produce everything, but that's what the free market is for. At that point, the government would really only be needed to see to national defense (as opposed to the current US model of global power projection). It would be reduced to mere coordination of effort towards greater self-sufficiency. There is absolutely no reason why the US, for example, cannot sustain itself in perpetuity without much in the way of global trade. This is why we have this push towards globalism today, because global trade powers demand the elimination of national boundaries that prevent the smooth flow of goods and services.