What happens when you cut off the ability for people to specialize and exchange? The answer is that you slow down technology progress—or even regress. There are studies to prove this, e.g. what happened Tasmania 10 000 years ago when it was isolated as the waters rose. But we don’t have to look back some 10 000 years. Look what has happened with societies such as North Korea or some of the Arab countries when people have been cut off from the ability to specialize and trade.