Ethnic identity refers to a set of characteristics by which an individual is recognizable as a member of a discrete group united by ties of blood and heritage. Ethnic identity forms the core of national identity for most of the world's people. Scholarly debates in global studies center on nature of ethnic identity--whether it is immutable and primordial or a social construction shaped by dynamic historical conditions and crafty ethnic politicians. The fate of ethnic identity is also a key issue of debate in the current literature on globalization. On the one hand, many observers argue that globalization erodes distinct ethnic identities by erasing boundaries that separate people and unleashing forces that would create a “global culture.” Others argue that globalization reinforces exclusive ethnic identities as a more interdependent world exposes more visible difference through more frequent contact. Furthermore, as transnational migration has led to ethnic diversity across the globe, minority ethnic groups have asserted their rights and called upon their collective identities in order to build solidarity and to affirm their group’s claims to territory and to resources. This essay expands on the definition of ethnic identity and briefly examines the historical relationship between ethnic identity and national identity in the context of global studies. It then surveys alternative explanations for the role that ethnic identity plays in international relations. Finally, it provides an overview of the debates over the effects of globalization on the continued role of ethnic identity in world politics.