On Monday, the South Korean government disclosed for the first time the reason behind the United States’ designation of South Korea as a “sensitive country.” The decision reportedly stemmed from “security issues” related to a research institute under the U.S. Department of Energy.

The South Korean Ministry of Foreign Affairs stated that the United States conveyed this information. This marks the first substantial communication between South Korea and the U.S. a week after news reports broke out on March 10.

However, the Ministry of Foreign Affairs did not reveal specifics about the security issues. A Foreign Ministry official simply stated that there was nothing more to explain beyond the official stance.

Some experts suggest that the Ministry of Foreign Affairs statement’s phrase “security issues related to a research institute under the U.S. Department of Energy” is open to interpretation. It remains unclear whether the security issues resulted from a mistake on the U.S. side or if there were any faults on the South Korean side. However, it seems clear that there was an attempt to leak critical information handled by the U.S. research institute.

A government source speculated that the Ministry of Foreign Affairs’ announcement regarding “security issues” could indicate a matter that might be viewed as a “counterintelligence issue” between South Korea and the U.S.

The Department of Energy, which deals with nuclear energy, energy, and advanced technology, ultimately aims to ensure U.S. security and prosperity. Due to the sensitive nature of its work, the Department is known for its stringent security measures. In some cases, issues like technology leaks may invoke concepts of defense and counterintelligence that go beyond mere security concerns.

This source believes that the Department of Energy may have been reluctant to provide South Korea with specific explanations due to its closed operational structure. This lack of communication may have affected the Ministry of Foreign Affairs and the Ministry of Science and ICT, the Department’s counterparts in South Korea.

Speculation has emerged that the issue may be linked to the arrest of Dr. Sue Mi Terry, a Korean-American North Korea expert, last July. Terry was accused of violating the Foreign Agents Registration Act by allegedly sharing sensitive information with South Korea’s National Intelligence Service. However, since the U.S. has not imposed sanctions or trade restrictions on South Korea, the breach may involve operational mistakes rather than intentional espionage.

The U.S. reportedly plans to clarify the situation during South Korean Trade Minister Ahn Duk Geun’s upcoming visit to Washington. Ahn is scheduled to discuss the matter directly with U.S. Energy Secretary Chris Wright.

While the issue raises concerns, analysts note that South Korea’s previous designation as a “sensitive country” in the 1980s and 1990s was eventually lifted after diplomatic pushback. This suggests the current tension may not spiral into a larger conflict. However, with the Trump administration expected to take a more hardline stance on trade and security costs, some fear the situation could escalate depending on how the U.S. frames the issue in the coming months.

On Monday, the South Korean government disclosed for the first time the reason behind the …

U.S. Labels South Korea ‘Sensitive’—But What’s Really Behind the Move?