Supreme Court Upholds Four-Year Term for Ex-Soldier Who Sold Military Secrets

South Korea’s Supreme Court has upheld a four-year prison sentence for a former Army soldier convicted of selling classified military information to a Chinese national, judicial officials said Friday. The material included information connected to joint South Korea-U.S. exercises, the United Nations Command and South Korean military drills.

The ruling, issued last month, also confirmed a fine of 20 million won and the forfeiture of 19.07 million won. The top court found no legal error in the lower court’s judgment. The former soldier’s identity was not disclosed.

According to the case record, the defendant met the Chinese national in Beijing in August 2024 while serving as an Army sergeant. The two had initially made contact through social media. The Chinese national claimed to be an official from a Chinese intelligence agency and asked the soldier to provide classified military information.

The former soldier accepted the request and supplied military secrets on seven occasions through February 2025. Prosecutors said he received about 17.26 million won in return. The disclosed material covered several sensitive areas, including allied exercises and information related to the U.N. Command.

Investigators also found that the Chinese national had given the soldier a wristwatch-style camera. The defendant used the device to photograph classified documents, enabling the information to be transferred without removing the original material from secure locations.

A military court initially sentenced the defendant to five years in prison. On appeal, the Seoul High Court reduced the term to four years, although it rejected his argument that he had not intentionally leaked military secrets. The Supreme Court’s decision leaves that appellate sentence and the accompanying financial penalties in place.

The case highlights the counterintelligence risks created when service members can be approached through ordinary online platforms and then cultivated during overseas meetings. It also shows how compact recording devices can be used to capture protected material inside controlled environments.

The final judgment closes the defendant’s ordinary appeal process and confirms that the disclosures were treated as deliberate violations rather than accidental mishandling. The prison term, fine and forfeiture together reflect both the national-security impact of the offense and the money received for the classified information.