Defining Armed Conflict under IHL: Importance of Classification

by Madhura Sapkal, Student at Maharashtra National Law University, Mumbai


Defining armed conflict decides whether International Humanitarian Law will be applicable or not. But IHL doe not provide a legal definition of armed conflict and rather divides the armed conflict into two categories i.e. International Armed Conflict (IAC) and Non-International Armed Conflict (NIAC). The blog will discuss the importance of defining and classifying armed conflict. Further, it will look into the scope of application and give concluding remarks.


The International Humanitarian Law (IHL) which is also known as International Law on Armed Conflict poses the existence of an armed conflict as a condition for the applicability of the rules.

Armed Conflict (for a layman to understand) means a prolonged conflict between two groups that have access to arms and are controlling armed forces. The legal definition of Armed Conflict is not provided anywhere in the IHL and often interpreted using existing case laws and doctrines. The conditions for recognizing an armed conflict is the control of territory and intensity of the conflict. Though there is no legal definition, the Geneva Convention classifies armed conflict into two categories viz. International Armed Conflict (IAC) and Non-International Armed Conflict (NIAC). This classification is made on the basis of the parties involved. The applicability of IHL regulates various things in armed conflict such as the use of weapons, conduct of hostility and protection of civilians/victims. 

The Geneva Convention and its Additional Protocols are the backbone of the International Humanitarian Law along with Customary International Law. The Geneva Conventions have been ratified by all states. The Geneva Convention and its protocol which are applicable after defining armed conflicts shall apply to all cases of declared war or any other armed conflict between two parties, even if the state of war is not recognized by them.[i] The Convention also applies where there is the partial or complete occupation of territory. When the classification is made the respective Protocol either I or II will be applicable.[ii] This blog will discuss the importance of defining the armed conflict as well as classifying it.

Definition and Classification of Armed Conflict: Importance

The importance of defining armed conflict is that it decides whether International Humanitarian Law will be applicable or not. As International Humanitarian Law classifies armed conflict into 2 broad categories viz. International Armed Conflict (IAC) and Non-International Armed Conflict (NIAC), there are different protocols applicable to it. Protocol I and II of the Geneva Convention deals with IAC and NIAC respectively, therefore defining the category of armed conflict is important. 

The Tadic case has defined  armed conflict as “an armed conflict exists whenever there is a resort to armed force between States or protracted armed violence between governmental authorities and organized armed groups or between such groups within a State.[iii] This creates the difference between IAC and NIAC where the criterion for the latter is stringent as compared to the former. In order to declare the situation as NIAC, there has to be a minimum threshold of violence. But this threshold of violence is not specifically defined and leaves it on the respective states to decide. States often do not accept that internal conflict is going on because that is viewed as surrendering the sovereignty to International Law. The status and structure of the parties should be considered because one includes sovereign states and the other includes both sovereign states and organized groups. Further, in contemporary era, majority of the NIAC includes one or more foreign actors and their fluctuating involvement in the conflict changes the nature of armed conflict. Internationalised armed conflict is an emerging challenge while defining armed conflict.

Unlike protocol I, protocol II applicable to NIAC is less detailed. A significant difference can be noted in terms of status. The Geneva Convention grants special protection to civilians and persons hors de combat.[iv] But in IAC, International Humanitarian Law officially recognizes the status of civilians, combatants as well as other persons who are hors de combat including prisoners of war, sick, wounded etc.[v] However, in cases of NIAC, such status is not granted and therefore the standard of protection differs. In addition to this, the statute of the International Criminal Court differentiates between war crimes committed by those in IAC and by those in NIAC.[vi]

International Humanitarian Law provides for the combatant privilege which gives them immunity from criminal prosecution for belligerent acts that are committed by them during the course of the conflict. Belligerent acts such as carrying arms or conducting an operation, comply with International Humanitarian Law. Therefore, if the conflict falls under IHL, such acts will not be prosecuted. There are chances that such acts can be prosecuted by the domestic courts which are not capable enough in a situation of conflict to prosecute such offence.

Additionally, when soldiers are kept captive by an enemy organisation, they are prosecuted as prisoners of war. There is no combatant status given to non-state armed groups in NIAC so, they can be even punished for carrying arms around even if they had not fired it. Under Common Article 3 or even Additional Protocol II, there is no requirement that combatants are afforded the prisoner of war status in NIAC. Also, there is no provision restricting parties from prosecuting enemy combatants from taking up arms.[vii] The AP-II, constantly overlook the areas covered by IAC.

The Internationalized Armed Conflict is the situation when internationalized conflict occurs when armed conflict occurs between two different organizations within a state and one of them is supported by the foreign state. If the foreign state supports recognized government in armed conflict then it falls under NIAC but there is ambiguity when non-state armed groups are supported foreign state or non-state armed groups of foreign state. This category of conflict does not fit any of the above-discussed categories and is not recognized by International Humanitarian Law. In the 21st century, the number of NIAC exceeds the IAC, such ambiguity must be addressed for the proper implementation of the IHL.

Applicability of  human rights law

Another importance of defining armed conflict is that it can have serious humanitarian concerns. We have seen how the classifying definition impacts the application of IHL but identifying whether a given situation of violence in armed conflict or not has some serious consequences in the international legal system. There is a complex nexus between International Humanitarian Law and International Human Rights Law (IHRL). Both come in close proximity with each other as IHL protects the civilians who are not part of arm conflict and IHRL protects the dignity of an individual. When the situation of violence does not fall into the category of armed conflict then that situation will be governed by IHRL. 

IHRL has a narrow-angle for looking at the situation as compared to the IHL. For example, the detention of a person for security reasons would be considered lawful under IHL but not under IHRL. Both the laws differ in terms of applicability. The conflict situation differs from normal situations. In an armed conflict, basic fundamental rights are violated on large scale and applying IHRL in such situation is not feasible. Also, to held non-state armed groups liable under a court of law is far from possible in a situation of conflict. Therefore, if the situation comes under IHL, then all the parties including non-state armed conflict have to abide by it. On the other hand, in IHRL, there exists ambiguity under what circumstances it should be applied. Defining helps with the identification which in turn helps as to which substantive law should be implemented. IHL has outlined properly what constitutes war crimes and prosecutes accordingly. 

Sources of the definition of Armed Conflict

International Armed Conflict

The Geneva Convention of 1949 mainly deals with armed conflict. The Common Article 2 states 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. The Convention shall also apply to all cases of partial or total occupation of the territory of a High Contracting Party, even if the said occupation meets with no armed resistance.”

This is a broad definition that tries to expand the scope of application of the Geneva Convention so that provisions come into force even without formal declaration of war. IAC occurs when one of the High Contracting Parties has resources to support armed forces. According to the above definition, IHL comes into play even when there is an absence of hostilities. Also, there is no need for formal declaration or recognition of the war. The commentary of the Geneva Convention of 1949 states that “any difference arising between two States and leading to the intervention of armed forces is an armed conflict within the meaning of Article 2, even if one of the Parties denies the existence of a state of war. It makes no difference how long the conflict lasts, or how much slaughter takes place.” 

The protocol I of the Geneva Convention which protects victims in the IAC further extends the definition of the IAC and includes the people fighting against colonial domination, alien occupation or racist regimes. This fight comes under the right to self-determination.

Non-International Armed Conflict

Common Article 3 to the Geneva Convention along with Article I of the Additional Protocol II defines and determines NIAC under IHL. 

The Common Article 3 of the Geneva Convention applies to “armed conflicts not of an international character occurring in the territory of one of the High Contracting Parties.” Currently, all states have ratified the four Geneva Convention therefore it is applicable to all countries.

Article I of the Additional Protocol provides a specific definition. This Article applies to armed conflicts “which take place in the territory of a High Contracting Party (HCP) between its armed forces and dissident armed forces or other organized armed groups which, under responsible command, exercise such control over a part of its territory as to enable them to carry out sustained and concerted military operations and to implement this Protocol.” This definition being specific makes it narrower. It talks about territorial control of the party to the conflict so that the protocol can be implemented. The Common Article 3 covers broader areas by bringing under its ambit conflicts between non-state groups only but this definition restricts itself from including non-state armed groups by expressly mentioning armed forces and dissident armed forces or other organized armed groups. 

Scope of Application

The definition of armed conflict by various sources such as ICRC, tries to include as many conflict as possible but it is not supported state practice. The definition provided in the Tadic case is often referred to. This was also the first case where the internationalization of armed conflict was discussed. The tribunal in this case held that the IHL applies from the commencement of the conflict to the cessation of the hostilities in IAC. Applicability in the internal conflict is until a peaceful agreement is reached. This judgment also talks about the territorial aspect of armed conflict, it nowhere refers to the intensity of the conflict.

Under the IHL, the absence of the definition of ‘armed conflict’ creates ambiguity and confusion in the law.  The classification of armed conflict is mainly dependent on the parties involved in the conflict. But the question is, in the contemporary era, different situations of conflicts are emerging and the definition provided is not dynamic enough to define it. The criterion for NIAC even often fulfilled, states do not accept the existence of internal conflict. States are threatened by surrendering their sovereignty to international law. In Sri-Lankan war, the Liberation Tigers of Tamil Eelam (LTTE), the non-state group was declared a terrorist organization in many countries and as it was a conflict between government forces and non-state groups, it would fall under NIAC. The conflict had a sufficient degree of organization and territorial control also the conflict was with government forces. But Sri-Lanka did not rarified Protocol II though it was party to Geneva Convention, it could not be tried under IHL. 

While Article 3 gave clarity to the NIAC, in Protocol II the threshold for application is raised significantly which limits its scope. Therefore, the Additional Protocol II will only apply to situations where armed groups are exercising military control over a territory that is of a State Party and it will not apply to a conflict between dissident armed groups.

There is a lot of ambiguity when it comes to the definition of Non-International Armed Conflict. First of all, the conflict has to be in the territory of the High Contracting Party and the required threshold has to be met with as well as few situations are excluded from the definition.[viii]

The term ‘internationalised armed conflict’ is very complex because there are many factual circumstances that can be termed as international. The War on Terror in Afghanistan included non-state armed groups as well as international military forces. Earlier the conflict was between the Afghan government and Al Qaeda. But when the US intervened, the conflict became international. Again, when the Talibani gave up the control of the government, the conflict could again be defined as NIAC as US forces were supporting the newly formed government. As US troops have withdrawn and a peace agreement has been signed, how the scope of IHL should be. Taliban being the non-state armed group do not adhere to the obligations under IHL.

In the US Supreme Court’s decision in Hamdan v Rumfeld[ix], the question of classification occurred in the context of the US’s ‘war on terror’ in Afghanistan. A Yemeni national was caught in Afghanistan and was brought to Cuba and handed over to a military commission for trial. He filed a petition of Habeas Corpus stating that he should be tried by a competent tribunal under the Geneva Convention as a prisoner of war. The Government responded to this argument saying that it was a separate conflict of US troops with Al Qaeda and therefore Geneva Convention would not be relevant in this case. The court of appeals emphasized on the two legal categories of the conflict and held that the situation at hand did not fall into any of those. This conflict did not fall under Common Article 2 because Al Qaeda was neither a state nor a signatory to the Convention. The three different decisions were given by three different entities. The SC gave the final verdict that safeguards given NIAC will be given in this case. This case shows ambiguity in the definition and difficulty in the nature of the conflict.

Disclaimer – All views and opinions expressed in this article are personal and belong solely to the author(s) and do not necessarily represent those of the LAABh Foundation or the individuals and institutions associated with LAABh Foundation.


[i] Common Article 2, Geneva Convention 1949.

[ii] Additional Protocol I to the Geneva Convention of 12 August 1949, and Relating to the Protection of Victims
of International Armed Conflicts.

Additional Protocol II to the Geneva Convention of 12 August 1949, and Relating to the Protection of Victims
of Non-International Armed Conflicts

[iii] Prosecutor v Tadić, Case No IT-94-1-AR72

[iv] Rule 47. Attacking persons who are recognized as hors de combat is prohibited. A person hors de combat is:(a) anyone who is in the power of an adverse party;(b) anyone who is defenceless because of unconsciousness, shipwreck, wounds or sickness; or(c) anyone who clearly expresses an intention to surrender;provided he or she abstains from any hostile act and does not attempt to escape.

[v] United Nations Human Rights Office of the High Commissioner, Persons Hors de combat in Non-International Armed Conflicts, September 2017,

[vi]  Gertrude C. Chelimo, Defining Armed Conflict in International Humanitarian Law, Inquiries Journals, 2011, VOL. 3,

[vii] Right to participate directly in hostilities [Additional Protocol I Art. 43 (2)]

[viii] Article 1(2), Additional Protocol II to the Geneva Convention of 12 August 1949, and Relating to the Protection of Victims of Non-International Armed Conflicts

[ix] Hamdan v. Rumsfeld, 548 U.S. 557 (2006)

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