AP Photo

The sudden death of North Korean leader Kim Jong Il, and the presumptive elevation of his son Kim Jong Un, has cast a pall of uncertaintyover the region and in Washington. Last year, two military incidents, the torpedoing of a South Korean navy corvette and North Korea's shelling of an island village in the south, killed 50 South Koreans. The concern in the south and in Washington is that Kim Jong Un -- or perhaps one of his rivals for the throne -- may see an advantage in more such incidents as a means of creating a crisis and rallying support. For decades, South Korea and the United States have prepared for a big war on the peninsula. Does Seoul need to do more to prepare for more exotic and asymmetric attacks like those that occurred last year?

Kim Duk-ki, a captain in South...