A security community is a region in which a large-scale use of violence (such as war) has become very unlikely or even unthinkable. The concept of a security community is related to a group of states that enjoy relations of dependable expectations of a peace. The term was coined by the prominent political scientist Karl Deutsch in 1957. In their seminal work Political Community and the North Atlantic Area: International Organization in the Light of Historical Experience, Deutsch and his collaborators defined a security community as "a group of people" believing "that they have come to agreement on at least this one point: that common social problems must and can be resolved by processes of 'peaceful change. Peaceful change was defined as "the resolution of social problems, normally by institutionalized procedures, without resort to large-scale physical force". People in a security community are also bound by the "sense of community", the mutual sympathy, trust, and common interests.
The concept has not become a mainstream term in the field of international security despite its long history. After the end of the Cold War, the concept of a security community was adapted by constructivist scholars. A major impetus was the book Security Communities (1998), edited by Emanuel Adler and Michael Barnett. They redefined the security community by shared identities, values, and meanings; many-sided direct interactions; and reciprocal long-term interest. Several regions of the world have been studied in the security community framework since then, most notably the European Union, the Canada–United States and Mexico–United States dyads, Mercosur, and Association of South East Asian Nations (ASEAN). Michael Haas compared the Asian and Pacific Council, Asian-Pacific Parliamentarians Union, ASEAN, Indochinese Foreign Ministers Conference, South Asian Association for Regional Cooperation, Southeast Asia Treaty Organization, and the South Pacific Forum (later renamed the Pacific Islands Forum).