In the ceasefire of July 27 , 1953 , the DMZ was created . Each side agreed in the armistice to move their troops back 2000 m from the front line , creating a buffer zone 4 k wide . In the Armistice Agreement of July 27 , 1953 , the DMZ was created as each side agreed to move their troops back 2000 m from the front line , creating a buffer zone 4 k wide .