North's MDL troop deployment increases by thousands as de facto border takes shape

North Korea has increased the number of personnel for fortification work along the military demarcation line (MDL) since resuming construction in early March, according to military authorities, who believe the effort is intended to visibly reinforce leader Kim Jong-un's policy of treating the two Koreas as "hostile states."

About 1,000 troops were deployed to work north of the MDL across the western, central and eastern fronts during the first half of last year, they said. That number rose to between 3,000 and 5,000 during the first half of this year.

Construction reportedly continued through July and August, except on days of heavy rainfall.

The fortification work is gradually reshaping the landscape inside the North's side of the demilitarized zone.

Although the sequence varies by sector, the construction generally follows the same pattern: clearing vegetation and leveling the ground along the MDL, laying antipersonnel land mines, installing triple-layer electrified barbed-wire fences, building tactical roads, constructing guard posts and erecting anti-tank barriers along key tactical road corridors.

The anti-tank barriers are being built along the Northern Boundary Line, about 2 kilometers (1.2 miles) north of the MDL.

In particular, the land-clearing work has been carried out along what North Korea considers to be the MDL. As a result, North Korean troops frequently crossed into the southern side of the line last year, triggering repeated warning broadcasts and warning shots from the South Korean military.
North Korean troops also reacted sensitively to the warning shots, which led the government to consider limiting their use.

Under the South Korean military's rules of engagement, warning broadcasts are issued if North Korean troops advance to within 50 meters (164 feet) north of the MDL. If they cross the MDL into the South, warning shots are fired at designated target areas. If they continue advancing beyond 50 meters south of the MDL, troops are authorized in principle to use aimed fire.

Military sources said, however, that South Korea did not fire a single warning shot during the first half of this year.

Military authorities attributed the change to the near completion of North Korea's land-clearing work by the end of last year, which sharply reduced the number of MDL crossings by North Korean troops.

The assessment suggests that work near the MDL has been largely completed and that North Korea has shifted its focus to rear-area construction, including fences, tactical roads and anti-tank barriers.

It also indicates that Kim's goal of turning the MDL into a de facto border may be nearing completion.

The Joint Chiefs of Staff also expects the fortification project to be completed within one to two years, earlier than initially anticipated.

Military officials and analysts have expressed concern that the MDL physically reinforced by North Korea could eventually become a fixed reality.

If North Korea's objective were truly to create a "border" as it claims, the fortifications would be expected to focus on preventing defections. Instead, the fact that antipersonnel land mines have been laid in front of the electrified fences — on the southern side — rather than behind them suggests they are intended to target South Korea.

"The North's tactical roads are not simply defensive measures aimed at preventing defections and cutting off inter-Korean exchanges," Jeon Kyung-joo, a research fellow at The Asan Institute for Policy Studies, said. "They are part of the same broader trend as North Korea's recent deployment of additional multiple rocket launchers near the front line and its intensified military activities."

BY LEE YU-JUNG, LEE CHUL JAE [kim.jiye@joongang.co.kr]