US Seismologist Youlin Chen Detained in China Over Espionage Allegations

U.S. citizen and Chinese‑born seismologist Youlin Chen has been held in Beijing since November 2024 after Chinese security officials detained him during a visit to his parents. Chinese authorities have charged him with espionage, linking the case to his research on North Korean nuclear tests that received funding from the U.S. State Department and the Air Force Research Laboratory. No public trial has been held, and his family reports severe health deterioration while in custody.

The United States has classified Chen as a "wrongfully detained" American, and former President Donald Trump raised the issue directly with President Xi Jinping during a May 2026 visit to China. U.S. officials continue to demand that China provide due process and medical care for Chen, while Chinese officials maintain the case is being handled according to domestic law.