The United Nations has defined biological warfare as the use of any living organisms (e.g. bacteria) or infective material derived from them, in order to cause disease or death in humans, animals, or plants. The effectiveness of these organisms depends on their ability to multiply in the person, animal or plant attacked.

While the United Nations is a post-World War II institution, biological warfare is considerably older. Biological weapons have been used throughout world history: crops and livestock have been destroyed, water supplies have been contaminated, and humans have been exposed to lethal diseases.

The creation of modern biological weapons is the direct result of advances in the field of microbiology and genetics. For example, scientists have learned how to isolate strains of bacteria, enabling the mass production of pure bacterial colonies. Because of remarkable progress in microbiology, biological weapons are easily and cheaply produced...