Chinese Authorities Detain US Scientist for Nuclear Research

WHO:

CNN - Youlin Chen, an American scientist and seismologist.

CNN - US Senator Edward Markey.

CNN - President Trump.

CNN - Xi Jinping, Chinese leader.

CNN - Global Reach, a US non-profit organization.

CNN - Yufang Rong, Chen's wife.

CNN - Kieran Ramsey, chief investigative officer at Global Reach.

WHAT:

CNN - Chen has been detained in China for more than 18 months on spying charges.

CNN - Chen was charged with espionage on May 1, 2025.

CNN - Chen is the only American currently held in China designated as wrongfully detained.

CNN - Chen's research has been funded by the US State Department and US Air Force Research Laboratory.

CNN - Chen authored a technical report in December 2020 and a subsequent study in 2024 related to nuclear-test monitoring.

WHERE:

CNN - Chen was detained at the airport in Beijing after visiting his parents.

CNN - Chen was living in Boston prior to his detention.

WHEN:

CNN - Chen has been detained since November 2024.

CNN - Chen was charged with espionage on May 1, 2025.

CNN - Trump raised Chen’s case during a meeting with Xi Jinping in May.

WHY:

CNN - Chen's detention is suspected to be linked to China's expansion of its nuclear capabilities.

CNN - The case adds friction between the US and China as they attempt to stabilize ties.

HOW:

CNN - Chen was detained after being interrogated more than 100 times about his work on North Korean nuclear tests.

CNN - US embassy officials have visited Chen several times, but Chinese officials were present, preventing him from speaking freely.

(UPDATED July 15, 2026 06:39 UTC)

American scientist and seismologist Youlin Chen has been detained in China for over 18 months on espionage charges, making him the only American currently classified as wrongfully detained in the country. Chen was arrested at the Beijing airport after visiting his parents and has faced extensive interrogation regarding his research on North Korean nuclear tests, which has been funded by the US State Department and the US Air Force Research Laboratory. President Trump raised Chen's case during a meeting with Chinese leader Xi Jinping in May, highlighting the growing tensions between the US and China as they navigate their complex relationship.