In the duel between North and South Korea, the question now is who will pull the trigger first? The answer may be neither, but don't count on it. The dueling now focuses on two quite different flashpoints. The first is the West or Yellow Sea, where North Korea has vowed to open fire against any South Korean vessel intruding in its waters. One issue there is how to define which waters are North Korean. The North refuses to recognize the Northern Limit Line, set by the United Nations Command after the Korean War (1950-1953) and challenged by North Korea in...