1.1 Introduction
Despite the recent resurgence of large-scale interstate warfare, in particular the Russian aggression against Ukraine, most armed conflicts fought today remain ‘non-international’ in character. At the time of writing in mid-2024, non-international armed conflicts (NIACs) outnumbered international armed conflicts (IACs) by a factor of about ten to one.Footnote 1 One of the most important features that distinguish NIACs from IACs is the type of actors that take part in them. In a NIAC at least one of the warring parties will be a non-state armed group (NSAG), sometimes referred to as an armed non-state actor (ANSA), organized armed group (OAG), or simply as an ‘armed group’. For most of its modern existence, international law was not concerned with the behaviour of states or that of armed groups in such conflicts, as they were perceived to be purely internal matters that did not warrant any outside interference.Footnote 2 This changed abruptly when the drafters of the four 1949 Geneva Conventions adopted the first ever treaty text directly regulating certain conduct in NIACs: Common Article 3 (CA 3).
The scope of this new legal framework quickly expanded through the development of customary international law and the adoption of the 1977 Additional Protocols, most importantly Additional Protocol II Relating to the Protection of Victims of Non-International Armed Conflicts (AP II), which supplemented the rudimentary protection offered by CA 3.Footnote 3 Shortly after its adoption, commentators made clear that its provisions were equally binding on non-state parties to the conflict, that is, armed groups.Footnote 4 Yet, until today, the scope of obligations imposed on armed groups remains underdeveloped in law and practice.Footnote 5 One field where this underdevelopment has become increasingly evident is the administration of justice by armed groups. Like established and recognized governments, insurgent movements, especially those that take and hold territory, increasingly find themselves needing to govern.Footnote 6 In 2024, the International Committee of the Red Cross (ICRC) estimated that no fewer than 83 million civilians were living in areas under the exclusive control of armed groups.Footnote 7 In these areas, armed groups resolve disputes, impose penal sanctions and implement social control, including within their own ranks. To do so, they frequently establish courts or other judicial mechanisms.Footnote 8 This book aims to set out and evaluate the international legal framework governing these ‘irregular’ judicial institutions and the legal capacity of armed groups to pass penal sanctions in compliance with international law.
1.2 Armed Group Courts in Contemporary Armed Conflicts
They have, while under the ban of the law, and exposed to its punishments, been able to construct from bottom to top a whole system of effective courts of Justice. They are daily emptying the King’s Courts and filling their own. The Irish Bar looks on, part of it with consternation and part of it with secret sympathy, while the law business, in a litigious country, abandons the long established tribunals, to be discharged by makeshift courts, set up by an illegal organization, enforcing its decrees through universal intimidation.Footnote 9
This contemporary description of the so-called Dáil courts, established by the Irish Republican Army (IRA) in the 1920s, demonstrates that the challenge of the state’s monopoly on the administration of justice has always been a prominent feature of armed rebellion. This observation still holds true a century later. Indeed, many armed groups not only engage in armed struggle, but also challenge state authorities by establishing rival governance institutions.Footnote 10 In the past two decades alone, a large number of armed groups have established judicial systems of various levels of sophistication. Some of the most recent examples are Hamas in the Gaza Strip;Footnote 11 the Donetsk People’s Republic (DPR) and Lugansk People’s Republic (LPR) in Eastern Ukraine;Footnote 12 the Autonomous Administration of North and East Syria (AANES or Rojava);Footnote 13 Jabhat al-Nusra and the Islamic State (IS/Daesh) in Syria and Iraq,Footnote 14 as well as Ansar Dine; Al-Qaeda in the Islamic Maghreb (AQMI); and the National Movement for the Liberation of Azawad (MNLA) in Mali.Footnote 15
Other examples are the Liberation Tigers of Tamil Eelam (LTTE) in Sri Lanka; the Farabundo Martí National Liberation Front (FMNLF) in El Salvador; the Taliban in Afghanistan (before their 2021 takeover of the country); the Communist Party of Nepal-Maoist (CPN-M); the Revolutionary United Front (RUF) in Sierra Leone; the National Democratic Front (NDFP) and Moro Islamic Liberation Front (MILF) in the Philippines; the Armed Forces of the Forces Nouvelles (FAFN) in Ivory Coast; the Free Aceh Movement (GAM) in Indonesia; the Sudan People’s Liberation Movement (SPLM) in South Sudan; the Movement for the Liberation of the Congo (MLC) in the Democratic Republic of the Congo; the Kosovo Liberation Army (KLA); the Naxalites in India; the Revolutionary Armed Forces of Colombia (FARC) and the National Liberation Army (ELN) in Colombia; the Karen National Union (KNU) in Myanmar; and the National Resistance Army (NRA) in Uganda.Footnote 16
Although quantitative data remains scarce, several surveys confirm that the operation of judicial systems by armed groups is indeed a relatively frequent phenomenon. In a study based on a dataset comprising 127 internal armed conflicts between 1950 and 2006, for example, Huang found that 28 per cent of the armed groups monitored had established some form of courts.Footnote 17
Using a different dataset of 2,205 so-called during-conflict justice processes occurring in 204 NIACs between 1946 and 2011, Loyle and Binningsbø found that 10.3 per cent of these processes were conducted by rebel groups.Footnote 18 These processes – defined as ‘judicial or quasi-judicial processes initiated during an armed conflict that attempt to address wrongdoings that have taken or are taking place as part of that conflict’ – demonstrate that some armed groups are willing to provide for criminal accountability, including within their own ranks, through judicial processes.Footnote 19
Finally, drawing on more recent data collected on the rebel use of judiciaries, Loyle found that that between 1946 and 2017, 85 (or about 18 per cent) out of 466 surveyed armed groups adopted courts or some sort of formal judiciary.Footnote 20 While a more comprehensive empirical analysis of these processes is certainly warranted, these datasets support the conclusion that the use of courts and judicial processes by armed groups is not an isolated and sporadic occurrence but rather a relatively common practice during NIACs.
1.3 Courts and Judicial Proceedings as an Element of Rebel Governance
It is possible to identify several motives behind the creation of courts, conduct of trials and passing of penal sentences by armed groups. The establishment of courts can be a pragmatic tool for armed groups to ensure military discipline and respect for IHL among its members.Footnote 21 However, it may also constitute an aspect of what is frequently referred to as ‘rebel governance’. Rebel governance can be defined as ‘the set of actions insurgents engage in to regulate the social, political, and economic life of non-combatants during war’.Footnote 22 Actions of rebel governance go beyond acts of coercion and may also be aimed at influencing behaviour through symbolic processes.Footnote 23 Indeed, courts are a well-known symbol of sovereign power and their establishment can be part of a strategy to enhance an armed group’s legitimacy while simultaneously challenging that of the government in power. As put by Ledwidge, the establishment of separate courts is ‘the ultimate denial of the right of the state to determine the outcome of disputes and consequently the ultimate denial of that state’s legitimacy’.Footnote 24
It is therefore unsurprising that insurgent movements with a strong (religious or political) ideological component frequently decide to establish their own courts if the pre-existing judicial system is perceived to be built on values incompatible with those of their own (e.g. ‘Western’, ‘fascist’, ‘capitalist’, ‘un-Islamic’).Footnote 25 The CPN-M in Nepal, for example, established ‘People’s Courts’,Footnote 26 whereas many of the Islamist rebel factions in Syria (such as the Islamic State or Jabhat Al-Nusra) or Mali (MNLA, AQMI, Ansar Dine) created shari’a-based tribunals.Footnote 27
In addition to ideological considerations, almost every armed group needs to secure some level of support from the local population and establish legitimacy within the domestic sphere to survive.Footnote 28 This can be done, inter alia, by showing that its own fighters are being held accountable for transgressions, by punishing and preventing common crime, or by providing effective dispute resolution services to deal with disputes among the civilian population in areas controlled by the armed group. A good example is the shari’a-based court system established by the Taliban in Afghanistan long before their 2021 takeover of the country. Despite the brutal nature of the sentences imposed by the Taliban courts, their system was perceived by large parts of the population to be more transparent and efficient than the state judiciary.Footnote 29 Loyle’s work, in particular, demonstrates that judicial institutions help to confer legitimacy on rebel groups if they are effective in resolving disputes while also providing for procedural fairness and being inclusive of the local population’s views.Footnote 30 Indeed, where the state is absent, people are likely to offer their loyalty to those who can effectively provide order, adjudicate disputes, enforce contracts and fulfil redistributive functions.Footnote 31
Apart from the struggle for domestic legitimacy, the conduct of trials can also be a tool to send signals to international audiences.Footnote 32 Trials can demonstrate the organizational strength of an insurgent group by revealing its capacity to identify individuals and hold them accountable for certain behaviours.Footnote 33 Some groups are willing to comply with international norms but individual members may nonetheless breach international law in violation of the policies put in place by the group’s leadership.Footnote 34 In these situations, the establishment of courts can help to increase the group’s legitimacy by providing for criminal accountability.Footnote 35 Secessionist movements, for example, are particularly dependent on international recognition – especially when transforming from a de facto regime to a member of the international community – which will be more difficult to obtain if the group is known for systematically disregarding international law.Footnote 36 In addition, the symbolic aspect of establishing a court system might help such groups to demonstrate effective governance, which is recognized as a fundamental criterion for statehood.Footnote 37
In conclusion, armed groups use courts to implement discipline by enforcing compliance through judicial processes; to secure popular support and legitimacy among the local population or international audiences, and as a strategic tool to demonstrate symbolic power by using institutions commonly associated with state authorities. These motives also provide an indication as to which groups of individuals are likely to find themselves before a court or tribunal established by an armed group. The group may want to sanction its own fighters in order to maintain discipline within its ranks or to signal to an international audience that it is a responsible actor that adheres to international norms.Footnote 38 Moreover, civilians might be tried for offences against the group’s security, such as sabotage or collaboration with government authorities.Footnote 39 In addition, civilians might also be tried for common offences such as murder or theft where the armed group in control aims to maintain public order and wants to bolster its support among the local population. Finally, captured enemy fighters may be tried for war crimes or other conflict-related offences in order to demonstrate symbolic power and moral superiority over the adversary.
1.4 Trials by Armed Groups as a Legal Phenomenon
Whereas the creation of armed group courts has long been documented as a social phenomenon, until very recently international legal actors have either turned a blind eye to such practices or have summarily dismissed them as illegal and illegitimate. The UN Commission of Inquiry for the Syrian Arab Republic, for example, has referred to courts established by armed groups in various parts of the country as ‘unauthorized courts’Footnote 40 and spoke of ‘illicit trials’ that should be stopped.Footnote 41 What, however, is an ‘unauthorized court’ and when does a trial become ‘illicit’? Other international organizations and special mandate holders have equally struggled to measure the conduct of armed groups in relation to the administration of criminal justice against clear legal standards.Footnote 42 This is not surprising. The imposition of criminal sanctions is typically regarded as a core prerogative of the state and inherently linked to the concept of sovereignty.Footnote 43 From the perspective of the domestic law of a state on the territory of which these groups operate, every armed group court or tribunal will be illegal in the sense that it operates against the will of the established government and outside the existing constitutional framework. In addition, any act that is part of an insurgency against the government might be subject to domestic penal sanctions, often under the labels of ‘terrorism’ or ‘treason’.Footnote 44 Any attempt by an international organization or special mandate holder to engage with judicial institutions of armed groups could therefore be interpreted as an attack on the territorial state’s sovereignty and internal monopoly on the administration of justice.
International law, however, refrains from treating as illegal the uprising and insurgence of armed groups against the state in a national setting.Footnote 45 It does not contain a jus ad bellum internum and is, so to say, ‘neutral’ towards rebellion.Footnote 46 Nevertheless, international law regulates certain conduct of both armed groups and governmental authorities during a NIAC. Most notably, CA 3 contains a prohibition on the passing of sentences without a ‘regularly constituted court’ affording all the ‘judicial guarantees recognised as indispensable’. But what are these guarantees? What do they mean in the context of an armed group? Can they even be implemented by a non-state actor in the first place? Mégret, for example, has argued that ‘the right to a fair trial is not simply a right to be tried fairly by whatever organ one happens to be tried by, but arguably a right to be tried by an independent and impartial tribunal understood as a tribunal that is an emanation of the state’.Footnote 47 The question is, in other words, whether international law contains standards that, either directly or indirectly, protect a state’s monopoly on the administration of criminal justice.
This question is inherently interlinked with broader normative considerations on the implementation of international law in the context of non-state actors and especially the regime of IHL. It is widely acknowledged within the international community that IHL compliance of armed groups remains unsatisfactory and that enhancing it would constitute a worthwhile effort.Footnote 48 In this regard, it has been argued that supporting the operation of courts could be a helpful tool in improving the compliance of armed groups with IHL and increase the sense of ownership over their obligations.Footnote 49
That these considerations are not only of academic interest but also of significant practical relevance is evidenced by the so-called Sakhanh case, which inspired the initial research behind this book (and probably also many other works on this topic). On 11 March 2016, Swedish authorities issued an arrest warrant for Haisam Sakhanh, a Syrian national holding refugee status in Sweden, for allegedly having committed ‘aggravated crimes against international law’, including violations of CA 3 of the 1949 Geneva Conventions.Footnote 50 The prosecution produced evidence that Sakhanh had been a member of a Syrian armed opposition group and was involved in the execution of seven captured individuals belonging to the Syrian Armed Forces.Footnote 51 Sakhanh, however, denied any criminal responsibility and claimed he had merely executed a death sentence ‘imposed by a legitimate court’ on charges of murder and rape of civilians following a ‘procedure that met the basic requirements for a fair trial as required by international humanitarian law’.Footnote 52 The Stockholm District Court accepted the idea that the principle of sovereignty does not prevent insurgents from setting up their own courts but also held that the tribunal in question could not be regarded as independent and impartial and that the fair trial guarantees required under IHL had not been met.Footnote 53 Sakhanh was sentenced to life imprisonment and his conviction confirmed by the Svea Court of Appeal.Footnote 54
This case is not an isolated event but can be seen as part of a broader trend of engagement with the judicial systems of non-state actors. Similar cases have meanwhile been heard before domestic courts in other jurisdictions.Footnote 55 Ahead of its 33rd International Conference, the ICRC thus highlighted that implementing the IHL rules on fair trials in the difficult context which armed groups operate in poses a ‘complex and unresolved legal challenge’.Footnote 56
In June 2024, the International Criminal Court (ICC) convicted an individual for his involvement in a makeshift Islamic court in Mali – the first ever conviction by an international court for this type of crime.Footnote 57 Several other instances of penal sentences imposed by armed groups are currently the subject of investigations by the ICC Prosecutor, including in relation to the situations in PalestineFootnote 58 and Ukraine.Footnote 59 In addition, armed group courts have featured prominently in recent discussions of the concept of command responsibility.Footnote 60 While these events have sparked a fresh wave of scholarly commentary on this so far neglected and understudied issue,Footnote 61 a comprehensive doctrinal treatment of the status of armed group courts and the international legal framework applicable to the passing of sentences in NIAC is still missing. The present book aims to fill this gap.
1.5 Purpose and Scope of This Book
This book aims to provide a comprehensive analysis of the international legal framework regulating the operation of courts and passing of penal sentences by armed groups during NIACs. It is, therefore, not concerned with the administration of justice in relation to civil proceedings. The reason for this limitation is threefold. First, criminal proceedings conducted by armed groups pose a much bigger challenge to the authority and judicial monopoly of the state.Footnote 62 Second, criminal proceedings have a greater potential to interfere with the rights of individuals subjected to such proceedings, which may involve imprisonment and, potentially, even capital punishment. Finally, as will be shown in the chapters below, criminal proceedings and penal sanctions are subject to detailed protections and specific safeguards under multiple regimes of international law, in particular IHL and IHRL.
The following chapters will examine the legal framework for the passing of penal sanctions upon the group’s own members (‘internal’ administration of justice) as well as upon enemy fightersFootnote 63 and civilians (‘external’ administration of justice, including as part of ‘rebel governance’). Based on the importance of a clear legal framework on the administration of criminal justice by armed groups outlined in Section 1.4, the book will focus on two core issues.
First, it aims to explain if and to what extent armed groups have the legal capacity under international law to conduct trials and pass penal sentences. In other words, the book seeks to evaluate whether international law protects the judicial monopoly of the state by outlawing, directly or indirectly, the operation of courts and passing of penal sentences by armed groups as non-state actors. It will demonstrate that armed groups do enjoy a limited legal capacity to operate judicial institutions and pass penal sentences, even though this capacity will often be restricted in practice by the need to comply with exacting fair trial standards that were originally crafted in relation the judicial systems of states. It will also point out that this legal capacity is best described as a ‘weak permission’, meaning that international law neither prohibits nor explicitly authorizes such conduct. It will explain that, accordingly, international law does not attach any normative legitimacy to the passing of penal sentences by armed groups and that individuals involved in such conduct cannot derive any form of immunity from prosecution via the governmental authorities from such limited permission.
Second, the book explores whether international law not only allows but requires armed groups to conduct trials and pass penal sentences under certain circumstances. The book thus aims to answer whether certain legal obligations applicable to armed groups implicitly require the use of penal sanctions by such groups. It has been pointed out, for example, that if armed groups had no possibility to impose penal sanctions through courts, perpetrators of serious violations of IHL might go unpunished in areas where the state is unable to enforce the law.Footnote 64 In connection with this point, it is often argued that armed groups are required to ‘ensure respect’ for IHL and their military and civilian leaders will need to use penal measures in order to comply with the doctrine of command responsibility.Footnote 65 However, if such penal sanctions are not themselves administrated in compliance with international law, this would compromise any positive effect they might have on the enforcement and implementation of IHL.Footnote 66 The book will make the case that the use of penal sanctions is a lawful tool for armed groups to enforce discipline, compliance with IHL and public order in cases where the group disposes over institutions capable of administering such sanctions in line with the necessary judicial guarantees. However, it will also argue that this conclusion neither translates into an obligation to employ penal sanctions for that purpose nor into a duty to establish such judicial institutions.
Finally, it must be mentioned that the present book is primarily a doctrinal study aimed at clarifying the international legal framework governing the administration of criminal justice by armed groups. While the following chapters use a range of examples from all over the world to illustrate the legal questions at hand, they do not describe in detail the various judicial systems established by such groups or the social realities they operate in. For in-depth descriptions of selected case studies, interested readers may wish to consult René Provost’s insightful book Rebel Courts: The Administration of Justice by Armed Insurgents.Footnote 67
1.6 Structure of the Book
Following this introduction, Chapter 2 begins by addressing some vital preliminary legal issues, including the status of armed groups as international legal persons and the binding force of international law on such actors. The chapter will argue that the concept of international legal personhood is best understood as a descriptive term rather than a prerequisite for entities to incur international legal obligations. It will further explain that IHL, IHRL and international criminal law (ICL) contain relevant obligations governing the conduct of trials and passing of penal sentences during NIAC. It will demonstrate that whereas the direct application of IHL to armed groups as distinct collective entities is today widely accepted, the direct application of IHRL – despite strong normative arguments in favour – remains disputed and underdeveloped. Finally, the chapter aims to define entities referred to as ‘armed groups’ and clarifies who exactly is bound by the obligations applicable to them.
Chapter 3 subsequently outlines the types of trial situations and penal sentences that are covered by the protective scope of the relevant IHL norms, in particular in relation to the nexus requirement – which requires a link between the conduct in question and the armed conflict – and the extension of IHL to intra-party conduct. The chapter then proceeds to flesh out the meaning of the core IHL provision applicable to penal proceedings, namely CA 3 and its requirement of a ‘regularly constituted court’. It will argue that this phrase is best understood as incorporating the requirement that a court be ‘established by law’ and that the term ‘law’ in this context is not necessarily limited to ‘state law’. Finally, the chapter will explain that international law neither explicitly prohibits nor explicitly permits the passing of penal sentences by armed groups and, therefore, armed groups enjoy the legal capacity to pass sentences in the form of a so-called weak permission. This conclusion entails that individuals participating in the passing of penal sentences on behalf of armed groups may be lawfully prosecuted for their actions under domestic law.
Chapter 4 builds on the findings of Chapter 3 by analysing the remaining requirements for the passing of penal sentences, including institutional requirements such as independence and impartiality, as well as more specific due process guarantees prescribed by CA 3, AP II and customary law. The chapter will argue that despite the contested direct application of IHRL to non-state actors, IHL incorporates customary human rights law principles and standards of due process developed for states and indirectly provides for their application to armed groups. It will explain that while these standards might not have the same potential to ‘outlaw’ armed group trials as the requirement of ‘a regularly constituted court’, they are nevertheless difficult to meet by non-state actors in practice. This conclusion notwithstanding, Chapter 4 will also argue that proposals to downgrade the fair trial standards expected from armed groups should be rejected as they might equally water down fair trial guarantees expected from states and undermine the principle of belligerent equality.
Chapter 5 complements Chapters 3 and 4 by analysing how the standards identified in those chapters translate into the framework of ICL. It explains that while the passing of sentences without providing for necessary fair trial standards can amount to a war crime (and, potentially, a crime against humanity if sufficiently widespread and systematic) not every violation of the judicial guarantees required by IHL entails individual criminal responsibility. The chapter argues that this nuanced approach maintains incentives for armed group members to comply with fundamental fair trial guarantees without being unduly penalized for not meeting standards considered unrealistic in the context of a non-state entity engaged in armed conflict. However, it will also explain how a discriminatory interpretation of the nexus requirement, as applied by international criminal tribunals and advocated for by institutions such as the ICRC, criminalizes certain acts of rebel governance, in particular the punishment of common crimes in territory under armed group control, while the same acts may be carried out with impunity by state authorities.
Finally, Chapter 6 addresses the second theme identified in Section 1.5. It first analyses whether the capacity to impose discipline as an organizational requirement for the status of a party to an armed conflict implicitly presupposes the capacity to impose penal sanctions over members of the armed group. Moreover, it discusses to what extent an obligation to punish IHL violations with penal sanctions can be derived from the doctrine of command responsibility under ICL and whether the customary law duty to prosecute and punish war crimes, as applicable to states, can be extended to armed groups. The chapter argues that while courts and penal sanctions administered by armed groups can be a legitimate way to ensure respect for IHL and to avoid individual criminal responsibility on the basis of command responsibility, this conclusion does not translate into a positive obligation of armed groups as a collective to employ penal sanctions, let alone to set up judicial institutions. This conclusion notwithstanding, the chapter will point out that there is increasing state practice requiring armed groups to ensure accountability within their ranks.
_________
