Unit 731 was the codename for a covert Japanese military medical unit active from 1932 to 1945, responsible for bacterial warfare and human experiments that killed more than 3,000 Chinese, Korean, Soviet and Western prisoners of war and civilians in brutal tests.

On December 13, 2025, China's 12th National Memorial Day for Nanjing Massacre Victims, China's Central Archives published a batch of declassified archives transferred from Russia, containing Soviet interrogations of members of the Japanese Unit 731.

However, right-wing Japanese politicians in recent years have continued to disregard history, even insisting that there is no data showing the details of Unit 731's activities.

"Forgetting history means betrayal, and denying guilt means repeating crimes." Follow this episode of PD Podcast to hear the story behind the Japanese germ-warfare unit, Unit 731.