The Northern Limit Line or North Limit Line (NLL) – 북방한계선 (in ROK) – is a disputed maritime demarcation line in the Yellow (West) Sea between the Democratic People's Republic of Korea (DPRK) in the north, and the Republic of Korea (ROK) in the south. This line of military control acts as the de facto maritime boundary between North and South Korea.
Description
The line runs between the mainland portion of Gyeonggi-do province that had been part of Hwanghae before 1945, and the adjacent offshore islands, including Yeonpyeong and Baengnyeongdo. Because of the conditions of the armistice, the mainland portion reverted to North Korean control, while the islands remained a part of South Korea despite their close proximity.
The line extends into the sea from the Military Demarcation Line (MDL), and consists of straight line segments between 12 approximate channel midpoints, extended in an arc to prevent egress between both sides. On its western end the line extends out along the 38th parallel to the median line between Korea and China.
Origins
The 1953 Armistice Agreement, which was signed by both North Korea and the United Nations Command (UNC), ended the Korean War and specified that the five islands including Yeonpyeong Island and Baengnyeong Island would remain under the control of the UNC and South Korea. However, they did not agree on a maritime demarcation line, primarily because the UNC wanted to base it on or of territorial waters, while North Korea wanted to use .
In August 1953, shortly after the entry into force of the armistice agreement, the South Korean Syngman Rhee Provisional government, which opposed the armistice agreement, attempted to attack the DPRK on the west coast, ignoring the agreement. Accordingly, the United Nations Command set up the "Northern Limit Line" of the West Sea so that the ROK Armed Forces would not attack Hwanghae Island, and this is the starting point of the Northern Limit Line.
After the United Nations Command and North Korea failed to reach an agreement, it is widely believed that the line was set by the UNC as a practical operational control measure a month after the armistice was signed, on August 30, 1953. However original documentation recording this has not been found. The line was originally drawn to prevent South Korean incursions into the north that threatened the armistice. However, its role has since been transformed to prevent North Korean ships heading south.
A 1974 Central Intelligence Agency (CIA) research report investigating the origins of the NLL and its significance, declassified in 2000, found that the NLL was established in an order made on 14 January 1965 by the U.S. Commander Naval Forces, Korea. An antecedent line, under a different name, had been established in 1961 by the same commander. No documentation about the line earlier than 1960 could be located by the CIA, casting doubt on the belief that the NLL was created immediately after the armistice. The sole purpose of the NLL in this original order was to forbid UNC vessels from sailing north of it without special permission. The report noted, however, that in at least two places the NLL crosses into waters presumed to be under uncontested North Korean sovereignty. No evidence was found that North Korea had recognised the NLL.
While the NLL was drawn up at a time when a territorial waters limit of was the norm, by the 1970s a limit of had become internationally accepted, and the enforcement of the NLL prevented North Korea, in areas, from accessing significant territorial waters (arguably actual or prospective). In 1973, North Korea began disputing the NLL. Later, after the 1982 United Nations Convention on the Law of the Sea, the NLL also prevented North Korea from establishing an effective Exclusive Economic Zone to control fishing in the area.
It is unclear when North Korea was informed of the existence of the NLL. Many sources suggest this was done promptly, but in 1973 Deputy Secretary of State Kenneth Rush stated, in a now declassified, "Joint State-Defense Message" to the U.S. Embassy in Seoul that "We are aware of no evidence that NLL has ever been officially presented to North Korea." However, South Korea argues that until the 1970s North Korea tacitly recognized the line as a sea demarcation line. North Korea recorded in their 1959 Central Almanac a partial demarcation line close to the UNC controlled islands, at about three nautical miles distance, which South Korea argues shows North Korean acceptance of the NLL as a whole.