A core characteristic of world politics is the presence of communal conflict over ideas of national identity, inextricably bound to ideas of cultural identity. Increasingly, foreign policy decision-makers realize the importance of considering cultural factors in their calculations of how peoples will define the “self” that seeks “determination.” Although a collective's culture changes over time (through interaction with others and in response to external events), scholars and policy analysts sometimes treat identities as static, monolithic, and derived from cultures that rarely change. This leads policymakers to underestimate the extent to which culture influences and can be influenced by foreign policy. This paper integrates work in political science and psychology into a content analysis–based method for examining three major ways in which culture impinges on communal conflict. The utility of the approach is demonstrated with a case study of the Northern Ireland conflict from 1984 to 1986, which shows how the rhetoric of the competing nationalist/Catholic leaders (John Hume and Gerry Adams) was the site of debate over group culture, how differences in the rhetoric reflected different cultures of the conflict, and how the conflict has been affected by the foreign policy decisions of other actors.