Reducing U.S. forces in South Korea could invite miscalculation by North Korea, expert warns

Victor Cha, president of the Geopolitics and Foreign Policy Department and Korea Chair at the Center for Strategic and International Studies (CSIS), warned that reducing U.S. forces in Korea could lead to a miscalculation by North Korea.

In a video uploaded to the CSIS YouTube channel on May 30, Cha responded to a Wall Street Journal report that the U.S. Department of Defense is considering redeploying 4,500 U.S. troops stationed in Korea. While the U.S. government has denied the report, Cha said, “We believe this is a matter being seriously reviewed by the Pentagon and the military.”

“This reorientation by the Trump administration to focus most of the U.S. military attention on a Taiwan and First Island Chain contingency rather than on something like the Korean Peninsula [ …] could create an environment in which the North Koreans feel a little bit more confident than they should be and could lead to miscalculation,” he said.

Cha emphasized that troop reductions in Korea are not a new development, citing historical examples under President Dwight Eisenhower in the 1950s, President Richard Nixon in the 1970s and after the Sept. 11 attacks.

He noted that while 4,500 troops “is not an insignificant number,” removing them “does not undermine the ability to defend the Korean Peninsula.” He cited the capabilities of South Korean forces and U.S. contributions through air support, satellite reconnaissance and intelligence.

On the one hand, having about 20,000 forces on the peninsula still constitutes the American trip wire on the Korean Peninsula to ensure that if North Korea were ever to do something, the United States would be automatically involved.

However, he also highlighted that North Korea’s growing ties with Russia, the recovery of its trade relationship with China to pre-pandemic levels, and perceived uncertainties in U.S. commitments to its allies may affect the credibility of U.S. deterrence.

“It’s not just about capabilities, but how the adversary perceives the U.S. commitment,” he said, pointing to questions surrounding U.S. reliability across issues ranging from tariffs to security alliances.

Cha pointed out that “there were more provocations from North Korea in the first 100 days of the Trump administration than under any other U.S. president since Nixon,” calling it a warning sign.

“While the removal of a brigade will not necessarily undermine defense capabilities, it could sort of affect or make more ambiguous the deterrent signal at a time when the North Koreans are willing to be a little bit more belligerent and provocative than we’ve seen in the past.”

In a separate online forum on March 27 titled “What’s Korea’s next step?” Cha also predicted that a second Trump administration would likely pressure Seoul to accept more strategic flexibility for U.S. Forces Korea. He described the Korea-U.S. alliance as being in a “quiet crisis.”

Cha said the Pentagon is “almost certain” to push for such flexibility — a concept that allows U.S. Forces Korea to be deployed beyond the peninsula based on strategic needs. He also cited defense cost-sharing negotiations and North Korea policy as key factors straining the alliance.

BY CHO MUN-GYU   [yoon.soyeon@joongang.co.kr]