Chinese-born U.S. citizen and seismologist Youlin Chen was recently arrested for nearly two years and faces trial on accounts of espionage. These charges have raised concerns over U.S.-China relations. Chen’s work as a seismographer focuses on publishing U.S. funded work surrounding North Korean nuclear tests. This arrest of a US citizen contradicts China’s reputation for producing and promoting outstanding scholars and research.
July 26, 2026
President Xi Jinping
President of the People’s Republic of China
The State Council General Office
2 Fuyoujie
Xichengqu
Beijingshi 100017
People’s Republic of China
Dear President Xi,
The Committee of Concerned Scientists is an independent organization of scientists, physicians, engineers, and scholars devoted to the protection and advancement of human rights and scientific freedom for colleagues all over the world.
We are writing regarding US seismologist Youlin Chen, who studies the seismic characteristics of North Korean nuclear tests. According to public reports, on November 5th, 2024, Mr. Youlin Chen was arrested at Beijing International Airport as he got ready to return home to Boston after visiting relatives and lecturing at two universities. The reported basis for his detention consisted of allegations of “espionage.”
The Committee is deeply concerned about this detention, which has lasted more than 18 months so far. We note that Mr. Youlin Chen is a respected scholar whose work uses seismological data to study effects of nuclear testing. His research on North Korean test-blast seismic waves has been funded by federal agencies and featured Chinese academics as collaborators with publicly available Chinese data viewable on the Internet.
Chen has never performed classified work or had a U.S. security clearance, which speaks against the alleged accusation. We are further concerned by reports that he was subjected to harsh conditions during his detention, including excessive interrogations, not being able to move freely, and a lack of medication for his diabetes and other health problems.
We respectfully urge your government to review Mr. Youlin Chen’s case considering the principles of academic freedom, scholarly exchange, and international cooperation. His continued detention deprives the academic community of an important researcher and analyst. The detention of a prominent scholar under these circumstances risks undermining confidence in China as a country that welcomes rigorous academic inquiry and constructive international engagement.
We therefore respectfully request that the relevant authorities reconsider this matter and take the necessary steps to allow Mr. Youlin Chen to return to his professional research.
Thank you for your attention to this serious concern. We will continue to follow developments in this case closely and hope for a prompt and just resolution.
Sincerely,
Joel L. Lebowitz, Walter Reich, Eugene M. Chudnovsky, Alexander Greer
Co-Chairs, Committee of Concerned Scientists
CC:
Marco A. Rubio
Secretary of State
U.S. Department of State
2201 C Street, NW
Washington, DC 20520 USA
Phone: (202) 647-4000
X: @SecRubio
Ambassador David Perdue
Ambassador of the United States to China
U.S. Embassy – China
Beijing 55
Anjialou Road
Beijing, China, 100600
Phone: (+86) 10-8531-4000
Honorable Xie Feng
Ambassador of China to the United States
Embassy of the People’s Republic of China
3505 International Place, NW
Washington, DC 20008
E-mail: chinaembpress_us@mfa.gov.cn
Phone: (202) 495-2000