Who Were Unit 731

Unit 731 was a covert biological and chemical warfare research and development unit of the Imperial Japanese Army during World War II. It operated primarily in the Pingfang district of Harbin in Japanese-occupied China from 1935 to 1945. Officially known as the "Epidemic Prevention and Water Purification Department of the Kwantung Army," its true purpose was far darker. Unit 731 conducted human experimentation, often on prisoners of war and Chinese civilians, under the guise of medical research.

Establishment and Operations

Unit 731 was led by General Shiro Ishii, a microbiologist and lieutenant general in the Imperial Japanese Army. Ishii believed that biological warfare was the future of combat, and with the support of the Japanese government, he established the unit to develop and test biological weapons, vaccines, and chemical agents. It was part of a broader Japanese wartime program that included other secret units, such as Unit 100 and Unit 516, which focused on similar research.

Human Experimentation

The experiments conducted by Unit 731 were horrific. Prisoners were referred to as "logs" (Maruta), and many were subjected to inhumane procedures. Some of the documented atrocities include:

• Vivisection: Prisoners were often dissected alive without anaesthesia to study the effects of diseases and internal injuries. This included the removal of organs, limbs, and other parts of the body.

• Frostbite Testing: Prisoners were exposed to extreme cold, their limbs frozen to study the effects of frostbite. Limbs were often amputated to observe the effects of gangrene or frostbite progression.

• Germ Warfare: Unit 731 developed various biological agents, including anthrax, plague, cholera, and typhus, which were tested on prisoners. They were deliberately infected with these diseases, often resulting in slow and painful deaths.

• Weapons Testing: Explosives, flamethrowers, and other weapons were tested on prisoners to study their destructive effects on the human body.

• Rape and Forced Pregnancies: Women prisoners were raped by guards and male prisoners to test the transmission of sexually transmitted diseases, particularly syphilis. Pregnant women were often vivisected to study foetal growth.

Biological Warfare on Civilians

Unit 731’s experiments were not confined to its Harbin base. The Japanese military conducted field tests of biological weapons on Chinese villages. Planes dropped ceramic bombs filled with plague-infected fleas, and rivers were poisoned with cholera and typhoid. These attacks caused outbreaks of disease that killed tens of thousands of civilians.

Impact and Aftermath

The experiments conducted by Unit 731 are estimated to have killed between 200,000 and 300,000 people. Many who survived the experiments suffered from lifelong injuries, trauma, and illnesses. After the war, the U.S. government, interested in Japan's biological warfare research, granted immunity to Ishii and other top officials of Unit 731 in exchange for their data. As a result, most of those involved in Unit 731’s atrocities were never prosecuted, and many went on to hold prominent positions in post-war Japan.

The full extent of Unit 731's activities remained hidden from the public for decades, only gradually coming to light through testimonies from former members, survivors, and historians. The unit’s legacy remains a subject of profound controversy and horror in both Japan and China. Despite growing awareness, the Japanese government has historically been reluctant to fully acknowledge and apologise for Unit 731’s war crimes.