Just saw a post that Japan considered using bio weapons and I realized I do not know a legit case where bio weapons have been used. I mean I know examples for nuclear weapons (Japan) and chemical weapons (Vietnam) but cannot recall any for bio weapons.
There are plenty of texts on this. I find Jeanne Guillemin's book, Biological Weapons (Columbia University Press, 2006) to be a nice introduction to the topic. We know that the Japanese actually did use biological weapons in China, although their researchers may have exaggerated the fatalities these weapons caused. Most scholars also now agree that Anthrax was used in the Rhodesian Civil War that led to Black African rule in Zimbabwe. Richard M. Swiderski describes the campaign using evidence drawn from South Africa's Truth and Reconciliation Committee in his book, Anthrax: A History. And then there were the attempts to spread bubonic plague in the Middle Ages, the smallpox blankets allegedly distributed to Native Americans, the mysterious outbreak of tularemia during Stalingrad, etc. But the first two I mentioned are the most extensively documented.