Based on a review of over sixty publications, this article develops a research agenda for the study of contemporary total defence. Despite renewed policy relevance, the literature remains fragmented across national traditions, sectors, and levels of analysis. To address this gap, the article applies a multilevel-governance perspective and develops an integrated analytical framework for comparative research. It conceptualises total defence across four dimensions – domestic vertical governance, transnational linkages, cross-sectoral coordination, and horizontal state-society relations – thus providing a coherent basis for future scholarship while remaining open to diverse theoretical approaches.