What Is Unit 731?

Unit 731 was a covert biological and chemical warfare research and development unit of the Imperial Japanese Army that operated during the Second Sino-Japanese War (1937–1945) and World War II. It was established in 1938 under the command of Lieutenant General Shiro Ishii and was based in Pingfang, outside of Harbin, China.

Activities and Experiments


  1. Human Experimentation: Unit 731 is infamously known for its human experimentation on thousands of Chinese, Korean, Mongolian, and Russian prisoners of war, as well as some Allied prisoners. These subjects, often referred to euphemistically as “logs,” were subjected to a variety of brutal experiments, including vivisections without anesthesia, amputations to study blood loss, and forced infections with deadly pathogens.
  2. Weapon Testing: The unit developed biological weapons and tested them in various field experiments, sometimes on populated areas. This resulted in outbreaks of diseases and numerous civilian casualties.
  3. Harsh Conditions: Prisoners were subjected to other experiments such as forced pregnancies, exposure to extreme temperatures, and high-altitude tests in pressure chambers.

Aftermath and Controversy

  • Immunity for Data: After the war, many of the researchers from Unit 731 were taken into U.S. custody. Instead of being prosecuted for war crimes, many were granted immunity in exchange for sharing the data they had collected during their experiments. This has been a source of controversy and criticism, as it allowed perpetrators of heinous acts to escape justice.
  • Acknowledgment and Apologies: For many years, the activities of Unit 731 remained a closely guarded secret. Over time, details emerged, leading to international condemnation. Japan has since acknowledged the existence and activities of Unit 731, though some believe that the apologies and recognition have not been sufficient.
  • Memorial and Education: Today, the sites related to Unit 731 serve as a museum and memorial, educating visitors about the horrors that took place and the importance of ensuring such atrocities never happen again.

Unit 731 stands as a dark chapter in the annals of wartime activities, a grim reminder of the depths to which human morality can plunge in the name of science and warfare. The atrocities committed by the unit raise profound ethical questions about human experimentation, war crimes, and post-war justice. In “Factories of Death: Japanese Biological Warfare, 1932-1945, and the American Cover-Up,” Sheldon H. Harris delves into the disturbing history of Unit 731, highlighting the extensive nature of these war crimes and the subsequent efforts to conceal them.

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