This article explores the impact of domestic norms on regional security practices in a pluralistic security community in the transatlantic area. A security community is considered to be ‘a group which has become integrated, where integration is defined as the attainment of a sense of community, accompanied by formal or informal institutions or practices, sufficiently strong and widespread to assure peaceful change among members of a group with “reasonable” certainty over a “long” period of time’ (Karl W Deutsch, Sidney A Burrell, Robert A Kann, Maurice Lee Jr, Martin Lichterman, Raymond E Lindgren, Francis L Loewenheim and Richard W Van Wagenen (1957) Political community and the North Atlantic area: international organization in the light of historical experience (Princeton, New Jersey: Princeton University Press)). Recent studies have aligned the concept of security community with the practice turn in International Relations theory. Although practice theory is able to explain peaceful conflict resolution...