Unit 731 Was A Covert Biological & Chemical Warfare Research Unit Of The Imperial Japanese Army Ww2

Unit 731 was a covert biological and chemical warfare research unit
of the imperial Japanese army during WW2

They participated in lethal human experiments that are estimated
to have killed up to a half million people

The United States secretly gave the researchers immunity
for their war crimes in exchange for their data

The Soviet on the other hand tried and executed those involved
in Unit 731 that they were able to capture in Manchuria
(Khabarovsk War Crime Trials)