In the short-term, this country to country interdependence, that's making Korea watchers so nervous, makes all of our economies very vulnerable to conflict or other sources of disruption around the world. In the long term, such interdependence is a good thing. It makes our world smaller, closer together and hopefully someday will make wars simply too expensive and completely impractical for everyone.
The problem we have now is that there are still too many countries not included in this globalization. Granted, it's as often as not, their choice, but my belief is that the more people that we can get tightly wrapped up in this world-wide economic web, the better off we will all be.
Your comment implies that NK's sinking of the Cheonan (killing 46 sailors) and with them shelling Yeonpyong island (killing 2 marines + 2 civilians) is a justified response to SK "provocation" and "muscle flexing".
Thing are not too stable anywhere these days. Even in the U.S. there's an economic and political crisis that's making life harder for more and more of us.
As this crisis deepens the military is becoming more important, in fact central, to keeping this economic system functioning. But it's clear that the system continues to deteriorate. What next?
It's interesting how centralized much of our consumption has become. Not just in electronics, but pretty much everything. One case of salmonella can disrupt vegetables or ground beef in half the country. Problems in South Korea could disrupt how much of the DRAM supply? Of course, there is also the Middle East and oil. How much chip fab capacity would go with troubles in Taiwan?
It's a very interdependent world these days.