China Detains U.S. Seismologist on Espionage Charges, Ex-Official Cites Nuclear Test Cover-Up Fears

A U.S. seismologist, born in China and later naturalized as an American citizen, has been detained in China for nearly two years and faces espionage charges. Chen Youlin, who conducted research funded by the U.S. government to detect North Korean nuclear tests, is the sole American designated as "wrongfully detained" by the U.S. government currently held in China. His case, revealed by Reuters, adds another layer of friction to already tense U.S.-China relations. U.S. Secretary of State Marco Rubio declared Chen "wrongfully detained" on March 19, making his release a top priority for the U.S. government. Chen's wife, Yufang Rong, stated that the Trump administration had not publicly announced this designation to preserve diplomatic flexibility. A U.S. source familiar with the case indicated the administration is focused on securing his release from what they deem unjustified detention. Chen, a resident of Boston, Massachusetts, became a U.S. citizen in 2011. His wife and advocacy groups report that he is the only American citizen in China currently designated as "wrongfully detained" by the U.S. government. Rong mentioned that the White House and State Department informed her that President Trump raised Chen's detention with Chinese President Xi Jinping during his state visit to Beijing in May, and Xi pledged to look into the matter. However, no action has been taken by the Xi administration. Rong expressed concern that Beijing has already decided to convict Chen on espionage charges, which carry a maximum penalty of life imprisonment or even death in severe cases. She believes his trial will not be public. U.S. Embassy officials have visited Chen, but Chinese officials were always present, hindering free conversation. His lawyer was only permitted to meet him after more than 13 months of detention. Chinese officials have questioned Chen over 100 times about his research on seismic wave characteristics of North Korean nuclear tests. Former U.S. National Security Official Eric Lebson suggested that China might seek to use Chen's expertise to enhance its ability to conceal underground nuclear tests using a technique called "decoupling." Nuclear test experts have voiced similar concerns. The Trump administration accused China of conducting a low-yield underground nuclear test on June 22, 2020, and attempting to conceal it with this technology. Decoupling involves detonating a device within a large underground cavity to reduce the seismic shockwaves. China has denied conducting such a test. Chen was arrested at Beijing Capital International Airport on November 5, 2024, by Chinese state security personnel as he was preparing to return to Boston after visiting relatives and lecturing on his research. Initially, Chen was held in harsh conditions, including being forced to sit on a hard bench for extended periods without standing, reading, or exercising, and denied medication for his diabetes and other health issues. His current detention conditions are difficult to ascertain, but he has lost significant weight and receives inadequate food with minimal protein, fruits, or vegetables, and poor-quality medication. Chen was charged with espionage on May 1, 2025, but has not yet gone to trial. In December, Massachusetts Democratic Senator Ed Markey and two other senators urged Secretary Rubio to designate Chen as wrongfully detained, expressing deep concern for his safety and health.

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I believe that no matter what, they will find him guilty, and the trial will not be conducted publicly.