The monograph is a comprehensive analysis of the activities of the Organization of American States (OAS) in the context of ensuring security in the countries of the Western Hemisphere in the 21st century. The book discusses in detail the organization's approaches to solving the most priority problems: drug trafficking, terrorism, poverty and social inequality, cross-border criminality and cybercrime, i.e. everything that falls under the concept of new challenges and threats. The study of the evolution of OAS approaches to security contains valuable experience, the use of which is possible in other regions in the formation of global strategies and policies.