AbbreviationsList of FiguresIntroduction1 Introducing the Legal Quandary about Internment in Non-International Armed Conflict2 Exploring the Legal Approaches to Internment in Armed Conflict3 Initiating the Empirical Quest: Methodology4 The Hidden Dimension of States' Detention in Non-international Armed Conflict5 The Plurality of Armed Non-State Actors' Detention in Non-International Armed Conflict6 Objectivising Internment7 Epilogue The Roadmap to Legislating Unlawful Confinement in Non-International Armed ConflictBibliographyAnnex i – Interview QuestionnaireIndex