DMZ mine blast puts Seoul's NK outreach at risk

President Lee Jae Myung ordered the military on Tuesday to determine the cause of a land mine explosion near the inter-Korean border and take necessary measures, raising questions about how his administration, which has been pursuing dialogue with Pyongyang, might respond if North Korea is found responsible.

Possible responses range from resuming propaganda broadcasts along the border to adjusting military operations inside the Demilitarized Zone (DMZ) and seeking action through the United Nations Command (UNC). The government has yet to announce any specific measures.

“The military must work closely with the UNC to conduct a swift and thorough investigation and establish the facts transparently,” Lee said during a Cabinet meeting. “Necessary measures will then be taken based on the findings.”

His remarks followed an interim military investigation that found a very high likelihood that North Korean mines caused the Sept. 21 explosions, which injured three South Korean soldiers.

Defense Minister Kang Shin-chul and the Joint Chiefs of Staff (JCS) have pledged corresponding measures if the final investigation confirms that mines planted by North Korean troops caused the injuries.

One possible response is the resumption of loudspeaker broadcasts toward North Korea, a measure adopted by the Park Geun-hye administration following a North Korean mine attack in 2015.

Moon Seong-mook, director of the Unification Strategy Center at the Korea Research Institute for National Strategy, described the broadcasts as an effective means of pressuring Pyongyang.

“Loudspeaker broadcasts are a good option because they can be extremely painful for the North Korean regime,” Moon told The Korea Times.

He said North Korean authorities were particularly sensitive to outside information reaching their soldiers and residents. He cited the 2015 incident, when the broadcasts were followed by heightened military tensions and inter-Korean talks.

But Moon declined to speculate on whether the Lee administration would resume the broadcasts, which Seoul had halted as part of its efforts to ease tensions.

“You would have to ask the presidential office directly,” he said.

Moon acknowledged that renewed broadcasts could heighten tensions and cause anxiety among residents near the border.

Another possibility is adjusting military operations inside the DMZ.

Asked Monday whether the military was considering more aggressive DMZ operations, a JCS official said, “Military operations are fundamentally conducted offensively to secure operational initiative.”

The official said existing operations could be adjusted under military guidelines but stopped short of announcing additional operations.

The military has previously responded to North Korean incursions across the Military Demarcation Line (MDL) with warning shots and broadcasts, while expanding search routes and reinforcing protective equipment.

However, the military has temporarily suspended the next phase of its route-clearing operations following the explosions, pending a safety review.

Moon said any military response should be proportionate, arguing that planting mines across the border or shelling North Korean positions would not be appropriate.

“Military responses are fundamentally governed by the principle of proportionality,” he said.

He also suggested that disputes over the precise location of the MDL should be addressed through the UNC and mechanisms established under the Korean War armistice.

The scope of any response will depend partly on whether investigators establish that North Korean troops deliberately targeted South Korean soldiers.

Unlike the 2015 attack, which occurred along a regularly used military route, the latest explosions occurred in an area South Korean troops had for decades only rarely entered.

A JCS official said that distinction made it difficult to conclude that South Korean soldiers had been deliberately targeted.

Asked whether conclusive evidence of North Korean mine-laying would trigger an immediate response, the official said the Defense Ministry and JCS would review the available options.