The north's huge inventory of chemical weapons and perhaps one or two nuclear bombs could fall into unknown hands. If not used, they could be sold for ready cash to international terrorists. As civil war erupted, some troops along the demilitarized zone would almost certainly try to escape into the south. A strike against the south in these circumstances would probably be calculated to focus his forces on external rather than internal enemies. North Korea's 10,000 artillery pieces and huge special operations force would very likely achieve widespread destruction before U.S. and South Korean forces brought them to heel.
Peace is hell.
Those are worst-case scenarios being evaluated by military planners paid to prepare for catastrophe. But even optimistic scenarios contain troubling implications that South Koreans have yet to come to terms with. If north and south were to reunite peacefully, that would most likely set millions of refugees flowing south in search of food. U.S. commanders in Korea say responsibility for humanitarian aid would fall to South Korean forces and private aid groups, though they acknowledge the inevitable involvement of U.S. troops to provide logistical support. Then there is the financial cost of a reunified Korea, which almost makes the perpetuation of the 44-year hostile standoff seem desirable.