The lexicon bridges language, knowledge, and practices and indicates a catalogue of key concepts for 21st-century security. It presents an innovative catalogue of key thematic entries for security studies and practices in the 21st century. Contributions are written by both academics and practitioners, introducing not just definitions of key terms but also key applications via specific case-studies. The events of the last decades have redefined the approaches of various actors in international politics to the main security sectors: political, military, economic, environmental, and societal. Therefore, the main purpose of this lexicon is to provide an innovative didactic and analytical tool that encompasses the most essential terms and concepts in the field of security in the 21st century.

Marek Antoni Musioł is Assistant Professor at the University of Wrocław, Poland, and Deputy Director for international cooperation at the Institute of International and Security Studies. His research focuses on international security, hydropolitics, Central Asia, regional security complexes, and securitization.

Andrzej Polus is Professor at the Institute of International and Security Studies at the University of Wroclaw and the Head of the Department of Developmental and Regional Studies. His research focuses on the political economy of hydrocarbons management and Sub-Saharan African politics.

Marek Kulczycki is Assistant Professor of Military and Defence Studies at the University of Wrocław, Poland. He holds a doctorate in military sciences, and his research focuses on military security, national security, crisis management, and polemology.

Wojciech Szczerbowicz is Assistant Professor at the University of Wrocław, Poland, in the Department of Developmental and Regional Studies. His research focuses on international relations in the Arctic, with particular attention to how the region is constructed through policy and strategic/hegemonic narratives.