As a result of the attack, the Central Bank in Korea has announced they are taking actions to curb herd mentality.
I expect over the next decade more international issues occurring as economic tensions rise. When they occur, such as this one, it is likely the market reaction will bring surprises.
General thought would be US dollar strengthens in times of crisis. Natural resources could go either way. One would expect stock markets to fall. In any event, I'll reserve my predictions and just say, lets see market reactions. I doubt the Korean thing will be over in a day, lets see how this unfolds and the effect.