The Biological Weapons Convention (BWC), adopted in 1971 with entry into force in 1975, effectively prohibits the development, production, acquisition, transfer, stockpiling and use of bacteriological and toxin weapons. The treaty currently has 183 states parties. As the first disarmament treaty to ban a whole class of weapons of mass destruction, it has successfully deterred the acquisition of biological weapons for over forty years.
The Chemical Weapons Convention (CWC), adopted in 1992 with entry into force in 1997, currently has 193 states parties and similarly prohibits them from the development, production, acquisition, stockpiling, retention, transfer or use of chemical weapons. The CWC also introduced a strict regime to verify compliance and monitor the production of chemicals that could potentially be used in the production of chemical weapons.
These treaties are significant as they represent the collective international will to ban biological and chemical weapons and establish an international norm by which any country using such weapons is considered a pariah.