The book offers a critical and comprehensive examination of the concept of NIAC, including its normative foundations, threshold of activation, and corresponding personal, geographical, and temporal scope of applicability under International Humanitarian Law. It identifies and critically examines some of the most controversial aspects of modern NIACs, including notions of a 'global battlefield' and 'forever war' and provides practical guidance on identifying NIACs in real time. It is essential reading for international law academics, students and practitioners. This title is part of the Flip it Open Programme and may also be available open access. Check our website Cambridge Core for details.