KADIZ, short for Korea air defense identification zone,
is the designated airspace over land or water in which the identification, location, and control of aircraft is performed in the interest of South Korea's national security.
It extends beyond its territory to give South Korea more time to respond to possibly hostile foreign military aircraft.
Like any other air defense identification zone KADIZ is not defined in any international treaty or law and it is not part of Korea's airspace.
Despite KADIZ not being regulated by any international body the South Korean military says foreign military aircraft have to notify the country before entering the zone.
If a foreign aircraft trespasses into the zone without giving prior notification, Korea sends its fighter jets to identify the aircraft, asking where it's from and what are its motives as well as giving a warning.
If the foreign aircraft fails to respond to repeated audio warnings the Air Force could fire flares or warning shots.
And depending on the flying pattern of the foreign aircraft such as speed and altitude if it's determined that the "intruder" is a possible threat to national security the call could be made to shoot the aircraft down.
Kim Ji-yeon, Arirang News.