The applicability of international law to armed conflicts involving non-state armed groups: between status and humanitarian protection

This is a thesis about the applicability of the jus in bello to armed conflicts involving non-state armed groups. The thesis focuses on the thresholds of applicability. These are the definitions of actors and situations that activate the applicability of the jus in bello. The aim is to illuminate and critique the regulatory rationales behind the different definitions of actors and situations in the different thresholds. The evolution of the thresholds is reviewed chronologically. Accordingly, the enquiry ranges from the 19th century doctrines of recognition of belligerency and insurgency, through common article 3 and Additional Protocols I and II, to the law developed by the ICTY and included in the Rome Statute for the International Criminal Court. While the thresholds constitute the centre of the enquiry, their meaning and function are further elucidated by the analysis of the process of their assessment, as well as the extent of the substantive legal regime they activate. The central question of the thesis is whether there has been a gradual shift from a status-based rationale to one focused on the humanitarian protection of individuals, in the evolution of the thresholds of applicability. A status-based rationale fits with a system of horizontal regulation of state-like collective entities and allows considerations and perceptions of the ascription of status through legal regulation to determine the threshold of applicability. A humanitarian-protection rationale is more related to a system of vertical regulation irrespective of status and links the applicability of the law to the individual and her protection. The argument proposed is that such a gradual shift is indeed visible, if tempered by the continuous role that considerations of status have in conflict situations and the still largely decentralised system of assessment of the applicability of the law