The incident last week at Gyodong Island in which two Marines watching the North Korean coast fired their rifles at an Asiana airliner approaching Incheon International Airport revealed how our soldiers guarding the northwestern-most territory have increased their alertness since the deadly North Korean attacks last year.

Yet, it also exposed how poorly trained our front line guards are about what to do in a perceived emergency. In the case of the Marines on Gyodong-do, 35 kilometers northwest of Korea’s main airport, it proved the personnel were not able to tell civilian airliners from military aircraft.

It is appalling to think what might have happened if the Marines were in charge of anti-aircraft guns or surface-to-air missiles. The soldiers reportedly said they were just firing warning shots at the unidentified aircraft. The Asiana plane was later confirmed to have been flying some 12 kilometers south of the Marines’ position and was not out of the authorized flight route it had used since the airport opened 10 years ago.

Together, the two Marines fired 99 rounds from their K-2 automatic rifles for 10 minutes. Marine corps authorities said they acted in accordance with proper manuals on emergencies and thus deserve no punishment. However, the first thing they should have done was report what they had seen to their command and respond as instructed. This time, the Marines behaved as if they were reacting to a surface-level infiltration.

Last week, the Marine Corps launched the West Sea Defense Command to bolster the defense of the highly volatile northeastern area. We expect that the new command to start an intensive personnel education program on how to react to North Korean attacks and infiltrations from air and sea. Soldiers should be particularly reminded that firing at a civilian aircraft is not allowed unless it is confirmed to be a military threat. Before that, they should be taught how to distinguish between civilian and military aircraft.