Soldiers of the U.S. Army 23rd chemical battalion wearing gas masks gather at a tunnel in 2015.

Soldiers of the U.S. Army 23rd chemical battalion wearing gas masks gather at a tunnel in 2015. Ahn Young-joon/AP

There Are 5,000 Tunnels Under North Korea, and U.S. Soldiers Are Training To Fight In Them

North Koreans are "world class tunnelers."

Tensions are rising between the U.S. and North Korea, and the U.S. military is preparing. That means learning to deal with a unique tactical advantage that North Korea has within its borders: tunnels.

“The North Koreans are like mole people,” Dave Maxwell, a former Army colonel who fought in the Korea war and is now part of an educational organization on Korea, told NPR. In 2001, Donald Rumsfeld called North Koreans “world class tunnelers.”

Maxwell claims the country has an extensive underground network of 5,000 tunnels, many built far below the surface to be safe from aerial attacks. In the unlikely scenario of invasion, attacking soldiers would have to fight not only in the air and on the ground, but below ground-level, too.

A small portion of the U.S. military is already trained to fight in tunnels and constrained environments. But NPR reports that more soldiers are now being trained for tunnel warfare due to recent hostile exchanges between the U.S. and North Korea. Exactly how many has not been made clear. One training exercise involves dismantling a chemical weapons laboratory underground.

Initially built for an offensive against South Korea, the tunnels were discovered in South Korean territory in the early 1970s. For tourists willing to ignore Kim Jong-Un and Donald Trump’s verbal war over who has the biggest nuclear button, some tunnels can be visited in the demilitarized zone between the two Koreas (paywall).