China detains US seismologist who has studied North Korean nuclear tests

Youlin Chen, a Chinese-born American seismologist, has been detained in China for nearly two years on espionage charges, according to his wife. Chen's research involved analyzing seismic signatures from North Korean nuclear tests using publicly available data, with funding from the U.S. State Department and Air Force. U.S. Secretary of State Marco Rubio designated him as wrongfully detained in March. Chen has reportedly lost significant weight while in custody and is awaiting a closed-door trial. The case highlights ongoing tensions between the U.S. and China over espionage allegations and the treatment of American detainees.