Inside The Horrifying History Of Japanese War Crimes During World War II

Published April 12, 2023
Updated March 12, 2024

Germ Warfare

Japanese War Crimes Of Germ Warfare

Xinhua via Getty ImagesResearchers with Unit 731 conduct experiments on captive child subjects in China’s Jilin Province. November 1940.

Of all the Japanese war crimes, germ warfare was one of the worst. During World War II, Japanese units weaponized deadly diseases like the bubonic plague and knowingly released them onto Chinese civilians.

In the late 1930s, Japanese General Shiro Ishii established a medical facility near the Chinese city of Harbin (then part of the Japanese puppet state of Manchukuo.) Publicly, the facility was known as the Epidemic Prevention and Water Supply Unit. But Ishii had actually created the notorious Unit 731, which conducted a number of horrific medical experiments on civilians.

Unit 731
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Episode 51: The Horrors Of Japan’s Unit 731 During World War 2
From chemical weapons tests to frostbite experiments to amputations without anesthesia, the atrocities of Unit 731 rank among the most vicious in modern history.

The Guardian reports that Unit 731 conducted experiments meant to weaponize diseases. They gruesomely carried out vivisections of live prisoners to cultivate samples of typhoid, cholera, and other illnesses.

The unit also put together “bombs” that were filled with wheat, rice, or cotton — and fleas that were infected with the bubonic plague. When dropped on Chinese villages, these bombs released the infected fleas, which rapidly spread the devastating illness among civilians.

As many as 300,000 innocent people may have died from this germ warfare, but it took a long time for any sort of justice to be served. That’s because, after the war, the U.S. secretly granted immunity to Ishii and his collaborators in exchange for access to their inhumane research.

It wasn’t until 2002 that a Tokyo court acknowledged that Japan had employed biological warfare during World War II, admitting: “The evidence shows that Japanese troops, including Unit 731 [the secret experimental unit] and others, used bacteriological weapons on the orders of the imperial army’s headquarters and that many local residents died.”

author
Kaleena Fraga
author
A staff writer for All That's Interesting, Kaleena Fraga has also had her work featured in The Washington Post and Gastro Obscura, and she published a book on the Seattle food scene for the Eat Like A Local series. She graduated from Oberlin College, where she earned a dual degree in American History and French.
editor
Jaclyn Anglis
editor
Jaclyn is the senior managing editor at All That's Interesting. She holds a Master's degree in journalism from the City University of New York and a Bachelor's degree in English writing and history (double major) from DePauw University. She is interested in American history, true crime, modern history, pop culture, and science.