The question of relevance of international relations theory must be approached through an awareness of the distinctiveness of various perspectives’ relations to existing structures of power. It becomes, in effect, a matter of asking for whom and for what purposes of practical action the theory is or is not relevant. Critical theories of international relations, ranging from modernist to post-structural forms, share a commitment to challenging the naturalness of the existing world order and the acceptability of its dominant relations and practices of power. Critical theory focuses analysis on the effects of power on the differential ability of actors to control their own circumstances. It also goes beyond that theoretical contribution to provide impetus for practical political action in challenging, confronting, and disrupting existing relations of power. Thus, in the contemporary era, critical IR theory is relevant, among other ways, as a stimulus to resist empire in its many guises.