Classification of Armed Conflict
Generally, there are two main classifications of armed conflict in International Humanitarian Law (IHL): International Armed Conflict (IAC) and Non-International Armed Conflict (NIAC). A NIAC is also technically regarded as an armed conflict not of an international character.
IHL is a branch of Public International Law containing rules that seek, for humanitarian reasons, to protect the victims of armed conflict and restrict the means and method of warfare.
Armed conflict is a contemporary term for war. Thus, IHL is regarded as the law of armed conflict or the law of war. And while the ‘law of war’ may sound contradictory, because wars are generally thought to be unregulated, the rhetoric of battles from ancient times says otherwise. War can be regulated, it has been regulated for a long time by customs, and more regulations are now codified and ratified internationally.
Why is Classification important?
Classifying armed conflict is important in order to determine the rules that apply to a particular situation. And if the situation changes, the rules that apply may also change.
The Four Geneva Conventions of 1949 (GC I-IV) and their Addditional Protocols of 1977 (AP I and AP II) are the primary treaties of IHL. These conventions and protocols contain different rules that may not apply in all situations of armed conflict. A third protocol was adopted in 2005 to provide for an additional emblem (red crystal).
In addition to the Geneva Conventions and their Additional Protocols, many other conventions and treaties have been adopted to deal with issues relating to conduct of hostilities, protection of the civilian population and prohibited weapons. And besides these conventions, international customary law contains many rules that apply in situations of armed conflict.
What is an Armed Conflict?
Before we dive deep into the different classifications of armed conflict recognised by IHL, it is important to mention that not all situations of violence can be classified as armed conflict. In other words, not all resort to force can be called an armed conflict for the application of IHL.
The Geneva Conventions and their Additional Protocols do not contain an explicit definition of armed conflict, although they provide for the application of the rules to the different classifications. For example, Common Article 2 to the Four Geneva Conventions of 1949 provides that:
“… In addition to the provisions which shall be implemented in peacetime, the present Convention shall apply to all cases of declared war or of any other armed conflict which may arise between two or more of the High Contracting Parties, even if the state of war is not recognized by one of them.”
From the provision above, we can clearly deduce the existence of an “armed conflict… between two or more of the High Contracting Parties”, which is known as an international armed conflict. But the use of the term “armed conflict” itself leaves us with no sufficient clue as to what the term really entails.
Common Article 3
Common Article 3 to the Four Geneva Conventions of 1949 provides that:
“In the case of armed conflict not of an international character occurring in the territory of one of the High Contracting Parties, each Party to the conflict shall be bound to apply, as a minimum, the following provisions:”i
Again, this other provision specifies the application of Common Article 3 to situations of NIAC. But no specific article gives a blanket definition to the term ‘armed conflict.’
Caselaw
Helpfully, a widely accepted general definition of armed conflict was given by the Appeal Chamber of the International Criminal Tribunal for the former Yugoslavia in Prosecutor v. Tadic, thus:
“An armed conflict exists whenever there is a resort to armed force between states or protracted armed violence between government authorities and organised armed group or between such groups within a State.”ii
The above definition gives three situations of armed conflict that fall into either of the two aforementioned classifications. A resort to armed force between two or more states is referred to as an International Armed Conflict (IAC). Whereas, an armed conflict between a state(s) and an organised armed group or between two or more of such groups within a state is known as a Non-International Armed Conflict (NIAC).
International Armed Conflict (IAC)
As earlier mentioned, an IAC occurs when there is a resort to armed force between two or more states. For example, the Korean War (1950–1953) was an IAC between North and South Korea. Also, the US and UK-led ‘Operation Iraqi Freedom’ in 2003 involving considerable troop deployment by coalition forces to Iraq is another example of an IAC.
Additionally, IACs also occur when there is an armed conflict between a state and an international organisation. Or when there is a war of national liberation, in which peoples are fighting against colonial domination and alien occupation and against racist regimes in respect of their right to self-determination.
It is important to note that in practice and under customary law, a declaration of war is no longer necessary for a state of war to exist. It suffices for one of the parties to make its intentions clear by actually commencing hostilities.
Also, the determination of whether a situation qualifies as an IAC is irrespective of the reason that led to the conflict (jus as bellumiii), or the degree of the intensity of the conflict. The ICTY in Prosecutor v. Dusko Tadic stated that “even minor instance of armed violence, such as an individual border incident or capture of a single prisoner may suffice to cross the threshold for IHL to apply.”iv
IAC also involves cases of partial or total occupation of the territory of a high contrasting party by another state without the consent of the state whose territory is occupied.
The primary rules applicable to IAC situations are contained in the Four Geneva Convention of 1949, Additional Protocol I (AP I) of 1977 and Customary International Humanitarian Law Rules (CIHL).
Non-International Armed Conflict
A NIAC occurs when there is protracted armed violence between a government authority and an organised armed group, or between such groups within a State. Thus, NIAC is usually between the armed forces of a state and dissident groups or rebel groups within that State. Many armed conflicts today fall under this category.
Unlike IAC, for a situation to be classified as a NIAC, certain criteria besides mere use of arm must be met. There criteria are a minimum level of intensity in respect of the conflict and a minimum degree of organisation of the armed group(s) involved.
Indicators of Intensity
Some indicators to be considered to determine the intensity of the conflict include: The number and duration of individual confrontations; type of weapons and equipments used; number and caliber of munitions fired; the number of casualties; the extent of material destruction, among others.
Indicators of Organisation
Some indicators to be considered in respect of the threshold of organisation include: the existence of a command structure and disciplinary rules and mechanisms within the group; existence of headquarters; control of a certain territory by the group; ability to plan and carry out military operations, ability to speak with one voice, among others.
Both threshold of intensity and organisation must be satisfied for a situation to be classified as a NIAC. If one or both is not met, then IHL will not apply. In such situations, human rights law and domestic law are the applicable legal regimes.
Rules Applicable to NIACs
The primary rules applicable to NIACs are found in Common Article 3 to the Geneva Conventions of 1949, Additional Protocol II (AP II), and Customary IHL Rules applicable to armed conflicts not of an international character.
It is important to note that owing to the provision of Article 1, paragraph 1 of AP II, the protocol only applies to armed conflicts between State armed forces and organised armed groups, given that such a group exercises territorial control within the State.
IAC by Proxy
An international armed conflict (IAC) by proxy occurs when a state exercises overall control over a non-state armed group (NSAG) that is involved in a NIAC.
Take for instance, State A is involved in a NIAC with Rebels B. Then State C directly intervenes in support of Rebels B, and this support is such that State C has ‘overall control’ of Rebels B. The situation is no longer a NIAC but an IAC between State A and State C.
For there to be overall control, the intervening state must provide support and help in the planning or coordination of the NSAG’s military activity. In this siutation, the rebel group becomes equivalent of agents of the State.v Thus, the armed conflict is between the two states and not State A and Rebels B.
Mixed Conflict
It is also possible for an IAC and a NIAC to be be taking place at the same time and within the same territory. Thus, the situation has to be examined carefully to determine which parties are involved in the IAC and NAIC, respectively.
In our earlier scenario, If State C directly intervenes in the armed conflict in support of Rebels B but does not fulfill the ‘overall control’ test, the situation is that of a ‘double classification’, ‘mixed conflict’, or simultaneous existence of IAC and NIAC. That is to say, there is a NIAC between State A and Rebels B, and an IAC between State A and State C.
Thus, an armed conflict may be an IAC, a NIAC, or an Internationalized Armed Conflict (which is not a third option but describing a situation involving an intervening State). An Internationalized Armed Conflict may remain a NIAC, turn a NIAC into an IAC, or create a simultaneous existence of the two.
In our scenario, if State C had intervened in support of State A against Rebels B, the armed conflict would remain a NIAC.
Other situations of Violence
There are situations of conflicts that exist within the territory of a State that would not qualify as a NIAC, for failing to meet the required threshold of intensity and organisation. These situations such as internal disturbances of sporadic acts of violence are described as ‘other situations of violence (OSV)’.
Article 1(2) of AP II provides that the protocol shall not apply to situations of internal disturbances and tensions, such as riots, isolated and sporadic acts of violence and other acts of a similar nature, as not being armed conflicts.
In such situation of violence, the applicable legal regime is the human rights law, as well as the domestic law of the State. It is important to note that IHL and human rights are essentially distinct but complementary.
When does Armed Conflict End?
When an armed conflict ends also depends on its classification. An IAC ends on the “general close of military operations”. In situations involving prisoners of war, IHL will continue to apply for specifically affected persons until release, repatriation, or resettlement.
A NIAC ends when a peaceful settlement is achieved or hostilities have ceased. Also, because of the thresholds required to create it, a NIAC would also end when the conflict no longer meets the level of intensity required to create a NIAC or the NSAG is no longer organised.
i LawGlobal Hub, “Common Article 3 Geneva Convention 1949 (Full Text)” (LawGlobal Hub, September 28, 2022) <here/>
ii Prosecutor v. Tadic, ICTY Case No 211 (Part A, Para 70), p1758.
iii “What Are Jus Ad Bellum and Jus in Bello?” (International Committee of the Red Cross, November 12, 2015) <here>
iv Prosecutor v. Dusko Tadic, Decision on the Defence Motion for Interlocutory Appeal on Jurisdiction (Appeal Chamber), 2 October 1995, 17-94-1-AR para. 70.
v ICRC, ‘How is the Term “Armed Conflict” Defined in International Humanitarian Law?’ INTERNATIONAL COMMITTEE OF THE RED CROSS OPINION PAPER 2024
About Author
Inioluwa Olaposi is an International Humanitarian Law (IHL) enthusiast. He was part of a team of three that won the National International Humanitarian Law Moot Competition for Nigerian Universities, organised by the International Committee of the Red Cross (ICRC), and subsequently participated in the All-Africa Regional Rounds at Nairobi, Kenya.
