One border, 3 lines: Why another DMZ mine blast could be waiting to happen

The Sept. 21 mine explosion in the western Demilitarized Zone (DMZ) has become a major point of contention between North and South Korea. Seoul claims the incident is a clear violation of the Armistice Agreement, while Pyongyang dismisses the claim as a fabricated farce orchestrated by the South. South Korean Defense Minister Kang Shin-chul stated that "this is a clear violation of the Armistice Agreement," suggesting that North Korea is trying to strengthen the border.

In contrast, Kim Yo-jong, sister of North Korean leader Kim Jong-un, stated that "our soldiers have never crossed the border." The conflict stems from differing interpretations of the Military Demarcation Line (MDL), the land border between North and South Korea. While the MDL is clearly marked on the map attached to the Korean Armistice Agreement, its width has a margin of error of around 50 meters.

The original agreement set up 1,292 stakes as markers, but only 181 remain today. The surviving stakes are now spaced two kilometers apart, making it difficult to determine the exact boundary. Even satellite navigation systems sometimes produce contradictory coordinates for the same location, further complicating the issue. As a result, South Korea, North Korea, and the United Nations Command have each drawn their own reference lines, leading to three different versions of the MDL.