There seems to have been a shift in the state-centric vision of international relations, following the increasing role of non-state actors (NSAs) on the international scene, particularly in the context of armed conflicts. Ezequiel Heffes, Marcos Kotlik and Manuel Ventura, editors of International Humanitarian Law and Non-State Actors, present through this collection of contributions an overview of legal issues arising from this new reality. The editors draw on their personal experience to explain how NSAs contribute to the development of international humanitarian law (IHL) and to suggest that in order to promote respect for IHL by all parties involved in an armed conflict, this new role should be given due consideration from a legal standpoint. The review aims to confront critically the position taken in the volume, assessing the pros and cons of an increased recognition (and potential legitimisation) of NSAs, with a particular focus on non-state armed groups. It discusses, in particular, the implications of this process for the exercise of sovereign rights and respect for fundamental guarantees, especially in relation to the powers to detain and to adjudicate.

One of the least clarified areas of international law is the legal regime applicable to non-international armed conflict (NIAC) – that is, where hostilities occur between state and non-state actors (NSAs) or between two or more NSAs.1 This can be explained by the reticence of states to grant legality to such movements and their preference to label them as criminal movements or terrorist groups.2 The result is that the regulation of NIAC is still limited to the application of Common Article 3 of the Geneva Conventions of 1949 (GCs) and their Additional Protocol II of 1977 (Additional Protocol II or AP II).3 While Common Article 3 provides only a rudimentary framework of minimum standards, Additional Protocol II, which usefully supplements it, is still less detailed than the rules governing international armed conflict (IAC). Moreover, in contrast to Common Article 3,4 it has not yet attained customary status.5 This situation is a source of concern. Faced with the horrors committed in NIACs such as those in Rwanda, Sierra Leone and Liberia in the 1990s, and the awareness of an inadequate legal framework, the international criminal law (ICL) community decided to resort to international human rights law (IHRL) and ICL to fill the gaps of international humanitarian law (IHL) applicable to NIAC.6

Contemporary international conflicts are witnessing an increasing involvement of civilians — such as, for example, suicide bombers — in the conduct of hostilities. Unlike regular soldiers, however, whose job it is to fight, civilians are not allowed to participate in combat and may be tried under ordinary criminal law for such activity. The question that this paper will attempt to answer is whether in the case where their engagement may lead to gross violations of humanitarian principles, they may be additionally subject to war crimes proceedings pursuant to international humanitarian law (IHL).

In order to assess the applicability of the war crimes' regime to civilians, this paper will be structured as follows. Part 2 will define who is a civilian. Part 3 will examine the position of international jurisprudence and doctrine on the question whether civilians may also be liable for war crimes and under what conditions. The fourth part will draw the conclusions.