TIL the US is accused of using bio weapons against the Chinese and North Koreans in the Korean War. Chinese troops started getting infected with Cholera, Smallpox, Bubonic Plague and Meningitis between January and March 1952

https://en.wikipedia.org/wiki/Allegations_of_biological_warfare_in_the_Korean_War

https://www.reddit.com/r/todayilearned/comments/15oyzs7/til_the_us_is_accused_of_using_bio_weapons/