They were planning on releasing biological weapons that really could have wiped out most of the planet. They just needed a bit more time to perfect it.
Some here would have given them that time.
I want every single person who is whining about the "poor helpless sweet lovable Japanese" to agree infect themselves with one of the deceases developed by Unit 731 and be treated only with the medical treatment available in 1945.Why? And how does that answer the basic question? When is it moral to kill an innocent child?