Neither nationalism nor ethnicity is vanishing as part of an obsolete traditional order. Both are part of a modern set of categorical identities invoked by elites and other participants in political and social struggles. These categorical identities also shape everyday life, offering both tools for grasping pre-existing homogeneity and difference and for constructing specific versions of such identities. While it is impossible to dissociate nationalism entirely from ethnicity, it is equally impossible to explain it simply as a continuation of ethnicity or a simple reflection of common history or language. Numerous dimensions of modern social and cultural change, notably state building (along with war and colonialism), individualism, and the integration of large-scale webs of indirect relationships also serve to make both nationalism and ethnicity salient. Nationalism, in particular, remains the pre-eminent rhetoric for attempts to demarcate political communities, claim rights of self-determination and legitimate rule by reference to “the people” of a country. Ethnic solidarities and identities are claimed most often where groups do not seek “national” autonomy but rather a recognition internal to or cross-cutting national or state boundaries. The possibility of a closer link to nationalism is seldom altogether absent from such ethnic claims, however, and the two sorts of categorical identities are often invoked in similar ways.