The Northern Limit Line (NLL) is a disputed inter-Korean maritime demarcation line in the West Sea. The 1953 Armistice Agreement which was signed by both North Korea and the United Nations Command ended the Korean War and specified that five islands including Yeonpyeong island, Baengnyeong island would remain under UNC and South Korean control.
However, North Korea has never recognized the NLL, which was drawn unilaterally by the U.S.-led United Nations Command when the 1950-53 Korean War ended, and demands that the line be drawn farther south.
Areas near the border have been the scene of a number of bloody inter-Korean clashes. The two sides fought naval gun battles in the area in 1999, 2002 and 2009. In 2010, the North torpedoed a South Korean warship in the area and shelled a South Korean border island.
North Korea could launch provocations at any time and the South should be ready for such possibilities. Pyongyang is the most belligerent nation that can break whatever promises it has made depending on its strategies.
Korea cannot safeguard peace only by words alone. Having a firm mindset about what Korea would do in case of provocations is the way to deter provocations.