South Korean soldiers clear an underground facility as part of Freedom Shield drills in Paju, South Korea, March 17, 2025. (Cornelius McLean/U.S. Army)
SEOUL, South Korea — U.S. and South Korean troops honed their underground combat skills using drones and breaching tools as part of a recent large-scale joint military exercise across South Korea.
More than 370 soldiers from both countries trained for four days at an underground facility in Paju, about 20 miles from the North Korean border, to defend against subterranean threats, according to a South Korean army news release.
South Korean multilegged robots searched for entrances and exits to underground bunkers before troops equipped with explosives and power tools deployed to destroy a mock enemy’s water supply and ventilation access, the release said.
The allies also used micro unmanned aerial vehicles, about the size of a human hand, to sniff out enemy positions and improvised explosive devices, according to the release.
“South Korean and U.S. soldiers were able to work as a single team,” South Korean army Lt. Col. Hwang Hyun-cho said in the release. “In particular, it was a good opportunity to gain various combat experiences in underground facilities and come up with improvements.”
A robot picks up a simulated improvised explosive device during a Freedom Shield drill in Paju, South Korea, March 17, 2025. (Cornelius McLean/U.S. Army)
The underground training was part of Freedom Shield, a biannual, 11-day joint exercise that ended Thursday. More than 19,000 South Korean troops and an unspecified number of U.S. personnel participated in drills across the country.
U.S. and South Korean conventional and special operations forces train regularly for underground warfare. South Korea’s military estimates that since the 1950-53 Korean War, North Korea has secretly dug thousands of tunnels in preparation for future conflict.
These tunnels could serve as storage sites for weapons of mass destruction or as subterranean transport routes for North Korean troops, the news release said.
South Korea has discovered and either destroyed or converted some tunnels into tourist attractions.
On Nov. 20, 1974, U.N. Command troops patrolling the southern side of the Demilitarized Zone discovered a tunnel crossing the border. As they probed further inside, North Korea detonated an explosive device, killing two and wounding six U.N. Command personnel.
Four months later, the Military Armistice Commission — the U.N. Command body responsible for investigating armistice violation — accused the North of constructing the tunnel.
“The North Koreans responded that the alleged tunnel incidents were fabricated,” a U.N. Command report to the U.N. Security Council stated on Oct. 31, 1975.
In 1978, South Korea discovered a tunnel a mile long and 12 feet wide about 30 miles north of Seoul. The site was later converted into a tourist attraction.
