Background: The preventive branches of public health have the task of promoting, maintaining and improving people's health. Preventive diplomacy propagates actions, such as peace, promotion and maintenance of peace. Eradicated diseases are a "silent" potential danger - a biological weapon. Such is the case with smallpox. In 1980, the eradication of smallpox was declared worldwide. Russia stores smallpox virus strains at the State Research Center for Virology and Biotechnology (Vector) in Koltsovo, near Novosibirsk, while the United States (US) stores strains in Atlanta at the Center for Disease Control and Prevention. Methodology: "The most painless way" to prevent an act of bioterrorism and international protection of the population from an infectious disease is through preventive diplomacy. Conclusion: Conventions and national legislation are harmonized, but the need for strong regional and global cooperation, the exchange and indication of relevant information, coordination and mutual assistance in situations of biological risk remains crucial.