South Korea's military classifies North's nuclear sites as joint secret, undercutting presidential defense

Unification Minister Chung Dong-young delivers a statement clarifying his remarks regarding the location of a nuclear enrichment facility in Kusong, North Korea, at the Government Complex in Jongno District, central Seoul, on April 20. [NEWS1]

 
South Korea's Defense Intelligence Agency (DIA) has confirmed that the locations of North Korea's uranium enrichment facilities are classified as combined South Korea-U.S. secrets, a designation that could undermine the Lee Jae Myung administration's efforts to contain the political fallout from a minister's public remarks about the site.
 
The DIA disclosed the classification in a written response to main opposition People Power Party (PPP) Rep. Lim Jong-deuk of the National Assembly's National Defense Committee on Wednesday shared with the JoongAng Ilbo.
 
"Specific location names, including the sites in question, are classified as joint secrets," the agency stated.
 
Combined secrets are classified information jointly produced or shared between Korea and the United States, including intelligence on North Korea's military movements and combined operational plans. The "secret" tier in Korea-U.S. sharing aligns with South Korea's Class II military secret of its three-tier system. 
 

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The confirmation puts the military at odds with President Lee, who defended Unification Minister Chung Dong-young after Chung publicly named Kusong, in North Korea's North Pyongan Province, as a primary North Korean nuclear site during a parliamentary session on March 6. 
 
On Monday, Chung maintained his remarks were based on already-public information, saying he finds it "deeply embarrassing" that a well-known fact is being characterized as an intelligence leak.  
 
The president echoed the defense on his X Monday, saying that "all claims and actions premised on the assumption that Minister Chung leaked classified information provided by the United States are wrong."
 
Intelligence analysts, however, say there is a critical distinction between research institutions or media outlets making analyses or estimates, and a senior government official formally confirming such information on the record.
 
Chung had claimed his reference to Kusong was based on statements by the director-general of the International Atomic Energy Agency (IAEA), but a statement provided by the IAEA of Director-General Rafael Grossi's remarks to the IAEA's board of governors made no mention of Kusong. 
 
The Unification Ministry later defended Chung by citing a CSIS report alongside earlier sources like a 2016 Institute for Science and International Security (ISIS) report. But on Tuesday, CSIS Korea Chair Victor Cha posted on X that the organization "has never done a report on nuke facilities at Kusong," distinguishing it from their analysis on North Korea's Yongdok-tong nuclear high explosive test facility in Kusong.
 
"This is less a revelation of an unknown secret and more a Rumsfeldian 'unknown known' [something everyone knew but no one officially acknowledged], now spoken aloud by the state," said Prof. Lee Byong-chul of Kyungnam University's Institute for Far Eastern Studies, warning that the remarks broke what he described as the "implicit rules of the Korea-U.S. alliance." 
 
Beyond the site name itself, Chung also referenced specific technical figures — including enrichment percentages and fuel rod counts — which analysts say could enable Pyongyang to infer the precise capabilities and orbital parameters of U.S. reconnaissance satellites.
 
The episode has also surfaced tensions between Seoul and Washington.
 

Defense Minister Ahn Gyu-baek, left, and Gen. Xavier Brunson, commander of U.S. Forces Korea, exchange greetings at Camp Humphreys in Pyeongtaek, Gyeonggi, on April 6, prior to a joint review of the bilateral defense posture. [NEWS1]

The Ministry of National Defense initially dismissed reports of a formal protest by Gen. Xavier Brunson, commander of U.S. Forces Korea, as "factually incorrect." 
 
But multiple sources told the JoongAng Ilbo that Gen. Brunson raised concerns with Seoul counterparts during a video conference in late March. 
 
Roughly a week earlier, Brunson visited the Defense Ministry in person, according to PPP Rep. Sung Il-jong, chairman of the National Defense Committee.
 
Rep. Sung demanded that the ministry "clarify the facts" surrounding Brunson's visits, citing the dates of March 10 and 11 at a press conference on Wednesday.
 

PPP Rep. Seong Il-jong, chairman of the National Assembly’s National Defense Committee, holds a press conference at the National Assembly on April 22 to address the controversy surrounding Unification Minister Chung Dong-young’s disclosure of a nuclear enrichment site in Kusong, North Korea. [YONHAP]

"The Ministry of National Defense is engaging in clever wordplay [...] not denying that the USFK commander visited, not denying that Minister Chung was discussed, but insisting it did not constitute a protest," Rep. Sung said. "I am certain that [Brunson] did warn Seoul about the loose lips that leaked classified intelligence." 
 
Later Wednesday, PPP members of the National Assembly's Foreign Affairs and Unification Committee held a separate press conference, calling on the Democratic Party to convene an emergency hearing on the matter and demanding Chung's immediate dismissal. 

BY YOON JI-WON, LEE YU-JUNG, SEO JI-EUN [seo.jieun1@joongang.co.kr]