In a 1988 book Korea: The Unknown War, historians Jon Halliday and Bruce Cumings also suggested the claims might be true. They questioned whether the North Koreans and the Chinese could have "mounted a spectacular piece of fraudulent theater, involving the mobilization of thousands", getting scores of Chinese doctors, scientists, and senior officials "to fake evidence, lie and invent medical fraud", allocating much of their already stretched logistical resource to defend against biological warfare, all for a propaganda campaign against US.
In 1989, a British study of Unit 731 strongly supported the theory of United States–Japanese biological warfare culpability in Korea.
https://en.wikipedia.org/wiki/Allegations_of_biological_warfare_in_the_Korean_War
