The DMZ and Border Politics
How a temporary ceasefire line became the world's most fortified border, and the complex politics of the Korean Demilitarized Zone.
Origins of the DMZ
The Korean Demilitarized Zone was established by the Armistice Agreement of July 27, 1953, which halted fighting in the Korean War without a formal peace treaty. The DMZ stretches approximately 250 kilometers across the Korean Peninsula, roughly following the 38th parallel, with a width of about 4 kilometers — 2 kilometers on each side of the Military Demarcation Line (MDL).
Despite its name, the DMZ is one of the most militarized borders on Earth. An estimated two million soldiers face each other across the line — roughly 1.2 million North Korean troops and 600,000 South Korean troops, supplemented by approximately 28,500 US military personnel. The zone is laced with landmines, anti-tank barriers, razor wire, guard towers, and surveillance equipment. North Korea has also dug at least four infiltration tunnels beneath the DMZ, discovered between 1974 and 1990, large enough to move thousands of troops per hour.