In the Armistice Agreement of July 27 , 1953 , the DMZ was created as each side agreed to move their troops back 2,000 m ( 2,200 yards ) from the front line , creating a buffer zone 4 km ( 2.5 mi ) wide .
Each side agreed in the armistice to move their troops back 2,000 m ( 2,200 yards ) from the front line , creating a buffer zone 4 km ( 2.5 mi ) wide .