By Chang Jae-soon

WASHINGTON (Yonhap) — An additional 150,000 U.S. troops would be necessary to cope with the aftermath in the event of North Korea’s collapse, such as securing the communist nation’s nuclear and other weapons of mass destruction (WMD), a U.S. think tank said Tuesday.

“North Korea might suddenly collapse — either as a result of war or the failure of its economy and government. After such a collapse, a key U.S. concern would be to find, seize, secure, and remove its WMD, in particular its nuclear weapons,” RAND Corp. said in a report, titled “Building the Army We Will Need.”

“In such an event, the greatest burden would likely fall on U.S. forces to eliminate these weapons … We estimate that a North Korean collapse would require an additional 150,000 U.S. troops over and above the forces already stationed and presumed to be available in the Asia-Pacific region,” it said.

Currently, about 28,500 American troops are stationed in South Korea to help deter threats from North Korea, a legacy of the 1950-53 Korean War that ended in a truce, not a peace treaty, which left the divided peninsula still technically at war.

The U.S. Army plans to cut troop levels from the current 490,000 to 420,000 by 2019 due to budge constraints known as “sequestration,” but the think tank said that the Army’s troop levels should rather increase to at least 545,000 to cope with such contingencies.

The institute also said that South Korea and the U.S. have been focused on coping with North Korea’s nuclear and ballistic missile threats, but they should pay greater attention to the North’s artillery capabilities and come up with countermeasures.

North Korea has more than 13,000 artillery pieces and multiple rocket launchers, about 8,000 of which are garrisoned within 100 miles of South Korea in protected underground facilities, RAND said. In addition to the prospect of nuclear weapons, North Korean artillery can fire a variety of chemical weapons, it said.

“North Korea may launch many shorter-range missiles against South Korea or Japan, potentially saturating their ballistic missile defenses. Worse, the U.S. strategy does not directly address the artillery threat to Seoul, including the potential use of North Korean artillery to employ WMD,” the report said.

That is to say, North Korea might use artillery to deliver nuclear weapons.

“Opinions differ about how close the North Koreans are to building a miniaturized weapon capable of fitting within their long-range missiles, but their recently revealed ability to separate uranium could give them the ability to build gun-assembled fission weapons similar to the W-33 the U.S. Army deployed in 1956,” the think tank said.

“This weapon was small enough to be fired from an 8-inch artillery tube, yet produced yields of up to 10 kilotons. If North Korea produced such a weapon, Seoul could be in range of nuclear weapons fired from existing, hardened, artillery sites,” it said.