China puts American scientist on trial after North Korea nuclear research

A Chinese-born American seismologist whose U.S.-funded research helped detect North Korea’s nuclear tests has been held in China for nearly two years and is now facing espionage charges, in a case that is adding fresh strain to already tense U.S.-China relations.

The detention of 54-year-old Youlin Chen, reported publicly for the first time, has been confirmed by his wife, U.S. lawmakers and two hostage advocacy groups.

Secretary of State Marco Rubio designated Chen as “wrongfully detained” on March 19, making his release a top U.S. priority. His wife, Yufang Rong, said the administration has deliberately kept the case largely out of the spotlight to avoid disrupting high-level diplomatic efforts

A U.S. official, speaking on condition of anonymity because of the sensitivity of those talks, said the administration remains “focused on gaining his release from his unjustifiable detention.”

Chen, a Boston resident who became a U.S. citizen in 2011, is currently the only American in China officially designated as wrongfully detained.

Rong said White House and State Department officials told her President Donald Trump personally raised Chen’s case with Chinese President Xi Jinping during a visit to Beijing in May, and Xi promised to look into it. She said no progress has followed.

The U.S. official did not confirm the discussion but said Trump and Xi maintain a “very good personal relationship” and described Chen’s detention as one of several issues shaping the broader U.S.-China relationship.

Rong fears Beijing has already decided her husband’s fate.

“I believe they will convict him no matter what and the trial will be behind closed doors,” she said.

China’s Foreign Ministry rejected the claim that Chen is being wrongfully detained, saying Chinese courts handle cases “according to the law.”

The Foley Foundation, which tracks Americans held overseas, believes Chen is among at least 12 U.S. citizens unjustly detained or prevented from leaving China.

According to Rong, U.S. embassy officials have visited Chen several times, but Chinese authorities have always remained in the room, preventing private conversations. His lawyer was not allowed to meet him until more than 13 months after his arrest.

She said Chen has been interrogated more than 100 times about his research into the seismic signatures of North Korea’s underground nuclear tests.

Eric Lebson, a former U.S. national security official advising the family, believes Chinese authorities are interested in Chen’s expertise because it could help improve techniques for concealing underground nuclear weapons tests.

Lebson said Chen has never held a U.S. security clearance or worked on classified projects. His research, funded by the State Department and Air Force Research Laboratory, relied on publicly available Chinese seismic data, was conducted with Chinese academics and was approved for public release.

Human rights groups have warned that China’s broad state-secrets law allows authorities to retroactively classify previously public information as a national security secret.

Chen was detained by Chinese state security officers at Beijing Capital International Airport on Nov. 5, 2024, as he prepared to fly home to Boston after visiting relatives and giving university lectures.

Rong said he was initially forced to sit for hours each day on a hard stool, denied books, exercise and medication for diabetes and other medical conditions. She said he has since lost between 30 and 40 pounds while surviving on inadequate food and poor-quality medication.

Chen was formally charged with espionage on May 1, 2025, but has yet to stand trial. The case is expected to be discussed during Xi’s planned visit to Washington in September.

Sen. Ed Markey, who led a bipartisan push to have Chen designated as wrongfully detained, said he hopes the increased attention will pressure Beijing to release him.

“It is my hope that increased attention on his unjust detention will force the Chinese government to do the right thing and release Dr. Chen,” Markey said.