Law of Non-International Armed Conflict


Civil wars are said to be ‘the most frequent and cruelest form of armed conflict’ and they remain undergoverned by IHL due to states’ reluctance to acknowledge a non-international armed conflict exists and the misguided belief that doing so confers legitimacy to the armed groups operating on their territory.1Tom Ruys, ‘The Syrian Civil War and the Achilles’ Heel of the Law of Non-International Armed Conflict’ (2014) 50 Stan J Int’l L 247 David Graham perhaps very aptly put it like this when discussing how to define a non-international armed conflict:

In undertaking that mandate, I was reminded of the words of Sir Hersch Lauterpacht: “[I]f international law is, in some ways, at the vanishing point of law, the law of war is, perhaps even more conspicuously, at the vanishing point of international law.” And, given the nuances of our current subject matter, I would think it appropriate to add to this statement: “If the law of war is at the vanishing point of international law, then, surely, the law related to non-international armed conflict is at the vanishing point of the law of war.” 2David E. Graham, ‘Defining Non-International Armed Conflict: A Historically Difficult Task’ (2012) 88 Int’l L Stud Ser US Naval War Col 43

When states came together to negotiate the Geneva Conventions of 1949 a single provision in all four treaties, Common Article 3, was applicable to NIACs. This was remedied somewhat by Additional Protocol II in 1977 which expanded the legal framework applicable to civil strife as did the development of the customary international law applicable to NIACs, particularly through international criminal tribunals. However, the difference between an IAC and a NIAC remains a distinction with a difference. Primarily due to the lack of prisoner of war status and combatant privilege, the fact that the law of neutrality does not apply in a NIAC, and also because a non-state group cannot be an occupying force.3Yoram Dinstein, ‘Concluding Remarks on Non-International Armed Conflicts’ (2012) 42 Isr YB Hum Rts 153 This month at the Diplomacy, Law and Policy Forum, we undertake a deep dive into the contested and debated issues relating to the law of non-international armed conflict, namely, spillover conflicts, the difference between Common Article 3 and Additional Protocol II NIACs, and internationalised non-international armed conflicts.

The Law Applicable to NIACs

The lack of any provision beyond Common Article 3 in Geneva Conventions I-IV which would regulate NIACs shows the reluctance of states to regulate internal wars. While the provision itself affords only basic protections it has been described as a mini-convention as the guarantees it enshrines are ‘elementary considerations of humanity’.4Corfu Channel Case (United Kingdom v. Albania); Assessment of Compensation, 15 XII 49, International Court of Justice (ICJ), 15 December 1949 While Additional Protocol II has fewer than twenty substantive provisions, it does more extensively regulate NIACs and extends the protections in CA3 on, inter alia, collective punishment and indecent assaults. It further provides special rules and protections for children, including education, the facilitation of family reunion, and proscription of recruitment into the armed forces.

Definition of a Non-International Armed Conflict

A non international armed conflict, as per Common Article 3, is not defined by it or any other provision in the Geneva Conventions. Additional Protocol II does define a NIAC but it is generally agreed that its definition is not the same as a NIAC under CA3. The International Criminal Tribunal for the former Yugoslavia in the Tadic case defined a NIAC as a situation of “protracted armed violence between governmental authorities and organized armed groups or between such groups within a State5Prosecutor v. Tadic, Case No. IT-94-1-AR-72, Decision on Defence Motion for Interlocutory Appeal on Jurisdiction, T 70 (Int’l Crim. Trib. for the Former Yugoslavia Oct. 2, 1995). This is widely accepted as a definition of a CA3 NIAC. An APII NIAC, however, is more limited in its application as it requires that the non-state group have territorial control, and engage in concerted military operations (this may be a higher threshold than protracted armed violence) and applies only to NIACs between a State’s armed forces and non-state organised armed groups, not within between groups.

Later jurisprudence has fleshed out the criteria required to fulfil the intensity and organisation requirements. In the Boskoski case, the ICTY noted the following in determining whether the intensity criterion had been reached:6Prosecutor vs. Boskoski, Case No. IT-04-82-T, Judgment, (ICTY July 10, 2008)

  • The number, duration, and intensity of armed confrontations (including whether there has been an increase in clashes)
  • Whether the fighting is widespread (including whether towns are besieged or supply routes blocked and roads closed)
  • The types of weapons and equipment used
  • The number and caliber of munitions fired
  • The number of fighters and type of forces participating in the fighting
  • The number of military and civilian casualties
  • The extent of material destruction
  • The number of civilians fleeing combat zones

This case also elaborated indicators to assess the level of organization of non-state groups:

  • The existence of a hierarchical command structure (this includes the existence of staff, spokespersons, or high command, internal regulations, issuing of political statements or communiqués, and identifiable ranks and positions)
  • The ability of the group to plan and launch coordinated military operations (including to define a unified military strategy, use military tactics, carry out large-scale or coordinated operations, control territory and territorial division into zones of responsibility)
  • The capacity to recruit, train and equip combatants
  • The existence of an internal disciplinary system on which trainings are held
  • The group’s ability to act on behalf of its members (including its ability to conclude cease-fire agreements and speak with one voice)

While the term ‘protracted’ may indicate that the violence should be ongoing for some time, in the Abella v Argentina case, the Inter-American Commission on Human Rights found a 30-hour confrontation between dissident forces and the Argentine military sufficient to constitute a NIAC.7Juan Carlos Abella v Argentina, Case 11.137, Inter-American Commission on Human Rights (18 November 1997).

Status in NIACs

Organised armed groups in a NIAC are not entitled to combatant immunity or prisoner of war status upon capture. Moreover, they can be prosecuted and punished for taking part in hostilities under domestic law even if they are complying with the laws of war and even if this involves the death penalty (unless they are a minor). Instead, in a NIAC, there are members of a state’s armed forces (who do possess combatant immunity), those in organised armed groups who have a continuous combat function (and are therefore targetable even when not directly participating in hostilities), and civilians who directly participate in hostilities (and are only targetable for so long as they do so).8See International Committee of the Red Cross (ICRC), Interpretive guidance on the notion of direct participation in hostilities under international humanitarian law, May 2009, and Michael N. Schmitt, ‘The Status of Opposition Fighters in a Non-International Armed Conflict’ (2012) 88 Int’l L Stud Ser US Naval War Col 119

Human Rights Law?

While it is now accepted that human rights law continues to bind states in a state of armed conflict, some question whether non-state groups are also bound by human rights obligations. This is all the more an issue when Security Council resolutions have adopted the view that human rights standards are to apply to such groups.9Gregory H. Fox, Kristen E. Boon & Isaac Jenkins, ‘The Contributions of United Nations Security Council Resolutions to the Law of Non-International Armed Conflict: New Evidence of Customary International Law’ (2018) 67 Am U L Rev 649

Internationalised Non-International Armed Conflicts

A NIAC can be internationalised and turned into an international armed conflict when there is foreign intervention either through foreign military forces being deployed in a NIAC or when multinational forces become involved for peacekeeping operations.10Ian Whitelaw, ‘Internationalisation of Non-International Armed Conflict’ (2016) 1 Perth ILJ 30 Internationalised conflicts occur when a foreign state intervenes in favour of an insurgent group fighting against the state, when there is an armed conflict between two or more non-state groups fighting on behalf of different states, or when there are direct hostilities between foreign states that are backing opposing sides in a NIAC.11ibid. The test for when a foreign state’s intervention on behalf of an armed group rises to the level of internationalising the conflict is the ‘overall control’ test as stated in the Tadic case. The tribunal held that “In order to attribute the acts of a military or paramilitary group to a State, it must be proved that the State wields overall control over the group, not only by equipping and financing the group, but also by coordinating or helping in the general planning of its military activity.”12Prosecutor v. Tadic, Case No. IT-94-1-AR-72, Decision on Defence Motion for Interlocutory Appeal on Jurisdiction, T 70 (Int’l Crim. Trib. for the Former Yugoslavia Oct. 2, 1995), para 131 While the International Court of Justice has disagreed with the conflation of tests for internationalising conflicts and state responsibility, it did not take a position on whether the overall control test is the applicable test for the classification of conflicts. Therefore, in terms of classification, the ‘overall control’ test continues to hold the field.13Case Concerning Application of the Convention on the Prevention and Punishment of the Crime of Genocide (Bosnia-Herzegovina v. Yugoslavia), International Court of Justice (ICJ), 11 July 1996, para 405

Spillover NIACs

A serious point of contention regarding the geographical scope of the application of the law of NIAC is whether it continues to apply to civil wars which spill over into a neighbouring state’s territory. The ICRC argues that “spill over of a NIAC into adjacent territory cannot have the effect of absolving the parties of their IHL obligations simply because an international border has been crossed. The ensuing legal vacuum would deprive of protection both civilians possibly affected by the fighting, as well as persons who fall into enemy hands”.14Quoted in Michael N. Schmitt, ‘Charting the Legal Geography of Non-International Armed Conflict’ (2013) 52 Mil L & L War Rev 93 This finds support in the Statute for the International Criminal Tribunal for Rwanda which states that the tribunal’s jurisdiction extends to “serious violations of international humanitarian law committed in the territory of Rwanda and Rwandan citizens responsible for such violations committed in the territory of neighbouring States”.15ICTR Statute, Art. 1 Moreover, Common Article 3 applies to any civil wars which occur on the territory of one of the High Contracting Parties, this does not confine it to one state’s territory but merely requires that it be taking place on any one of them. To constrain it to the territory of one state would perhaps go against the object and purpose of the Geneva Conventions and Pictet’s Commentary which urges Common Article 3 to be “applied as widely as possible”.16J. Pictet, Commentary to Geneva Convention I for the Amelioration of the Condition of the Wounded and Sick in Armed Forces in the Field (Geneva, ICRC, 1952), p. 50.

The better view seems to be that both IAC law and NIAC law operate in tandem, as not only is the state in a NIAC with the armed group in its neighbouring state’s territory but it is also in a parallel IAC with that state too by virtue of the fact that it is intervening militarily in its territory, even if it does not seek to target the state itself. However, the geographical scope of application of the law of NIAC is in question, as this usually applies in the entire territory of a state in which the NIAC is taking place “whether or not actual combat takes place there.”17Prosecutor v. Tadic, Case No. IT-94-1-AR-72, Decision on Defence Motion for Interlocutory Appeal on Jurisdiction, T 70 (Int’l Crim. Trib. for the Former Yugoslavia Oct. 2, 1995). In a spillover NIAC, it is unclear whether this further applies to the entirety of the neighbouring state’s territory.

The ICRC has also cautioned against the notion that a person ‘carries’ a NIAC with them to the territory of a non-belligerent state as this would potentially expand it to multiple states making the whole world a NIAC and a battlefield.18Michael N. Schmitt, ‘Charting the Legal Geography of Non-International Armed Conflict’ (2013) 52 Mil L & L War Rev 93 Any action taken against a person participating in hostilities in relation to a NIAC around the world should therefore not be considered a NIAC and be governed by international human rights law.19ibid.

Changes in the Law

Some, like Ruys, argue that in certain circumstances, non-state armed groups should be given combatant-like status so long as there is ad hoc consent of the de jure government.20Tom Ruys, ‘The Syrian Civil War and the Achilles’ Heel of the Law of Non-International Armed Conflict’ (2014) 50 Stan J Int’l L 247 He points particularly to the Syrian civil war in which the Assad regime treated members of such groups as terrorists, sentencing them to the death penalty for mere participation in hostilities.21ibid. This is an action which reduces the incentives for armed groups to comply with the laws of war, as Ruys puts it, for them, “the law is all sticks and no carrots”.22ibid. Moreover, it may even result in these groups, when they capture members of the armed forces, to impose on them measures which their captured comrades would also undergo.23ibid.

However, states would counter that while they appreciate the need to incentivise armed groups to comply with IHL they also need to incentivise them to not pick up arms and engage in civil war in the first place.24Claus Kreb & Frederic Megret, ‘The regulation of non-international armed conflicts: Can a privilege of belligerency be envisioned in the law of non-international armed conflicts?’ (2014) 96 Int’l Rev Red Cross 29 This argument is also premised on reducing the human suffering involved in a NIAC.25ibid. Megret further argues that the granting of combatant status ought to be conditioned on good humanitarian performance and most often than not armed groups do not seek a recognition of belligerency for humanitarian performance but to enhance the legitimacy of their cause.26ibid.

Historically, in some circumstances, states have given combatant status to rebel forces when they have recognised a state of belligerency. Before the Geneva Conventions, civil wars were of three kinds; rebellion, insurgency, or belligerency, with the last being the most intense and protracted form.27Yoram Dinstein, ‘Concluding Remarks on Non-International Armed Conflicts’ (2012) 42 Isr YB Hum Rts 153 The recognition of belligerency by a third state would invoke the law of neutrality between that state and the parties to the conflict, whereas recognition of belligerency by the parent state would apply the laws of war between them with the law of neutrality applying to the parent state and other states.28Tom Ruys, ‘The Syrian Civil War and the Achilles’ Heel of the Law of Non-International Armed Conflict’ (2014) 50 Stan J Int’l L 247 The parent state may be induced to recognise belligerency if third states were also doing so on a widespread scale.29ibid. The application of the laws of war meant that captured members of the armed group were to be given prisoner of war status by the parent state.

Armed groups are increasingly signing deeds and commitments such as those negotiated by organisations like Geneva Call in which they agree to particular regulations or codes of conduct, such as to not recruit children. Organised groups may also do this themselves, for instance, the Free Syrian Army issued a Proclamation of Principles which states that “We will do our utmost to uphold international humanitarian law and norms, including by treating prisoners humanely, even as the Assad regime engages in crimes against humanity.”30ibid. States may also decide on an ad hoc basis rather than through a formal recognition of belligerency to grant captured members of armed groups prisoner of war status, such as France with the Algerian Front de Liberation nationale (FLN).31ibid. The FLN, on the basis of reciprocity, also stated that it granted captured soldiers with POW status.32ibid. Very interestingly, the UK Manual of the Law of Armed Conflict states that, even if captured members of armed groups are not legally entitled to POW status, “[w]herever possible, treatment equivalent to that accorded to [POWs] should be given.”33ibid.


As NIACs become more frequent and more intense,34Yoram Dinstein, ‘Concluding Remarks on Non-International Armed Conflicts’ (2012) 42 Isr YB Hum Rts 153 the law applicable to civil wars becomes all the more relevant. And with this increase in relevance comes critique. The rise in regularity of such strife opens questions as to how relevant the law of NIAC remains and what changes it could undergo to ensure the object and purpose of IHL is kept in mind, namely to reduce civilian suffering. It may be that the granting of combatant status to rebel armed groups is a step in that direction, as it incentivises them to comply with IHL knowing they will no longer be liable for lawful acts of war if they do so. However, states are likely to be reluctant to do this as it assigns a level of legitimacy to such groups. As conflicts and their classification becomes messier, it may be that practice forces the hand of states to assign them this status in order to avoid the ‘fog of law’ on the battlefield.