New Archives Reveal Japanese Imperial Army Biological Warfare Secrets

Recent archival releases and historical research have exposed the scale of the Imperial Japanese Army biological warfare program during World War II. The Exhibition Hall of Evidences of Crime Committed by Unit 731 released a 185-page archive detailing the Hailar branch of Unit 731, also known as Manchuria Unit 543. These records show that the military disguised biological warfare personnel as conventional infantry to hide human experimentation and secret operations. The documents identify 156 members and confirm that the Soviet Union conducted trials of these personnel in Khabarovsk as late as 1950.

Simultaneously, historian Lim Shao Bin has brought attention to Unit 9420, a biological warfare unit headquartered in Singapore with branches across Malaysia, Indonesia, the Philippines, Thailand, Vietnam, and Myanmar. Unit 9420 produced plague-infected flea bombs and conducted experiments on prisoners. Evidence from Britain's National Archives, including testimony from former prisoner of war W. B. Williams, suggests British nationals were subjected to human experimentation in Singapore.

Lim is now calling for coordinated international pressure on the Government of Japan and the Federal government of the United States to release classified materials. This includes approximately 8,000 pathology slides from Unit 731 held by the U.S. government that have never been disclosed to the public. Researchers state the biological warfare program killed over 300,000 people in China.