Number of countries by their historical activity on biological weapons

Biological weapons are organisms or toxins used to cause death or harm through their poisonous properties. The closest a country got to using biological weapons everis recorded.

Source: OWID based on ACA (2022), NTI (2022), and CNS (2008).

Note: 'Allegedly' refers to situations where a country was charged by another country of pursuing, possessing, or using biological weapons, but the claims have not been confirmed by the country itself orimpartial observers.