Defense Minister Kang Shin-chul said at the National Assembly Defense Committee's annual audit on Oct. 7 that there are several spots south of the Military Demarcation Line (MDL) where North Korea may have laid mines. People Power Party lawmaker Yoo Yong-won noted that North Korean wooden-box mines are often placed 2 to 3 meters apart, so hundreds could be buried. Kang replied that the ministry also sees some areas that way, but he did not confirm a number.

The minister said that apart from the area of the Army's 25th Infantry Division, where a mine recently exploded, there are several other suspected sites. The ministry intends to investigate them jointly with the United Nations Command, confirm the facts and then take the necessary steps. According to the Kyunghyang Shinmun, the audit materials say that once the joint probe is finished the ministry will formalize the armistice violation and demand that North Korea stop and restore the area.

A request a year ago went unanswered

As the timeline has been disclosed, the Joint Chiefs of Staff spotted signs of digging south of the MDL last September using surveillance equipment and proposed a joint investigation to the UN Command. The Army's Ground Operations Command reportedly also sent five letters asking to look into the suspected armistice violation there. A joint investigation did not happen quickly, and on-site checks were delayed by about a year.

Kim Hong-chul, the ministry's policy director, confirmed at the audit that the earlier requests had not been accepted. Asked whether the UN Command caused the delay, he declined to elaborate, saying details of South Korea-US consultations cannot be disclosed. Lawmakers also recalled that when the ministry judged in June that the mines breached the armistice, the UN Command said on its website that they were defensive and not a violation.

How the picture changed after the blast

The situation changed after a mine exploded in the demilitarized zone on the western front last month and a soldier was injured. The South Korean military and the UN Command held a first joint preliminary investigation the next day, and the command officially confirmed a North Korean violation. The ministry concluded that a mine laid by the North caused the blast, and North Korea's foreign ministry called the finding fabricated. Kang said Pyongyang's reaction came a day late and appeared to show it had been caught off guard.

The military plans to verify the suspected sites on the ground and then follow up with mine clearance and other steps. Under the armistice, building structures or laying mines across the MDL is a contested matter, which makes prior consultation with the UN Command important. Military authorities say they are still communicating with the command about other suspected locations.

What remains: safety and the speed of procedure

The issue boils down to two points. One is how to keep soldiers and residents in border areas safe, and the other is how quickly South Korea and the UN Command, which holds armistice management authority, can run a joint response. If mine sites are confirmed, clearance will take considerable time and manpower, and the special status of the DMZ means the scope and method of work also need to be negotiated.

With inter-Korean relations strained, the matter reads as a diplomatic message as well as a military one. Because the government has publicly stated its plan to send a notice, North Korea's response and the results of the UN Command's follow-up investigation are likely to shape how border tensions are managed from here.