Each 179 entry explores the meaning and historical role of a key concept within international relations, outlining the debates that shape the field. The Encyclopedia demonstrates the wide-ranging, diverse and interdisciplinary nature of international relations, highlighting both the foundations of the field and the cutting-edge ideas shaping it today. It serves as an excellent entry point for further research, with a mix of brief summative entries providing a concise introduction to the topic alongside longer entries covering the most complex concepts in the field.