This chapter discusses the ways that strategic culture can be relevant to scholarship and policymaking with regard to international security. It first provides an overview of three main approaches to the study of culture and strategy, paying attention to political culture as well as the relationship between strategic culture and nuclear deterrence. It then examines various sources of strategic culture identified in the literature, along with theoretical issues related to strategic culture. In particular, it explores the link between constructivism and strategic culture, the question of continuity in state behaviour and how strategic cultural dilemmas can cause changes in security policy, and the ‘keepers’ of strategic culture. The chapter also asks whether non-state, state, and multistate actors can possess distinctive strategic cultures before concluding with an analysis of the role of strategic culture in the acquisition of — and threats to use — weapons of mass destruction (WMDs).