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International and Non-International Armed Conflicts- Differences

International Armed Conflict (IAC)


Armed conflicts are both a state of fact and a question of law. Since 1945, the United Nations prohibits the recourse to armed force in the relations between States, except in cases of self-defence or aggression. Nonetheless, the definition of aggression as a crime under international criminal law was adopted only in 2010. Besides, there is no international legal definition of armed conflicts as such.


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Since 1949, Common Article 2 to the four Geneva Conventions defines international armed conflict that triggers the application of humanitarian law.


Conventional Definition: Armed Conflict between States


According to conventional international humanitarian law, this term describes armed conflicts between two or more States, cases of military occupation of all or part of the territory of a High Contracting Party, as well as wars of national liberation (GCI–IV Common Art. 2, API Art. 1.3–4).

The definition of Common Article 2 covers cases of declared wars and any armed conflict where the state of war has not been recognized. Since 1949, the application of international humanitarian law is no longer dependent on the formalities of a war declaration, or, the recognition of the state of belligerency by one of the concerned States. This definition is based on objective criteria intended to avoid political polemics on qualification.


The law applicable to international armed conflicts also covers 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 and there are, therefore no armed clashes, or if those armed clashes are with non-state armed groups on the territory of the occupied State.


Jurisprudential Definition: International Armed Conflicts or “Internationalized” Armed Conflicts


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The complexity of contemporary armed conflicts involving a wide range of actors, from State to non-state actors and international armed forces, sometimes spilling over to the territory of States not officially parties to the conflict, raises questions of qualification and of law applicable to these actors and situations.


While the direct military involvement of several States is easy to establish, it doesn’t account for the reality of most contemporary armed conflicts, which defy formal legal criteria. Indeed, some armed conflicts can occur on the territory of several States without directly involving their national armies. Others occur on one national territory but involve non-state armed groups, operating from the territory of a neighbouring State, with or without the control of the latter.


Finally, some armed conflicts occur outside the national territory of one party to the conflict. It is also necessary to go beyond legal appearances concerning the non-state nature of an armed actor and to verify if it acts on behalf of or under the control of another State.


The difference between International Armed Conflict and Non-international Armed Conflict


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International armed conflict and non-international armed conflict are two distinct categories of armed conflicts recognized under international humanitarian law. While both types involve the use of armed force, there are several key differences between them. Here are the main distinctions:


1. Nature of Parties Involved

  • International Armed Conflict: In an international armed conflict, hostilities occur between two or more states. The parties involved are typically recognized as sovereign entities and can engage in war on behalf of their respective nations.

  • Non-International Armed Conflict: A non-international armed conflict, also known as an internal armed conflict, takes place within the territory of a single state. It involves armed confrontations between the state's armed forces and one or more organized non-state armed groups or between such groups themselves.

2. Applicable Legal Framework

  • International Armed Conflict: International humanitarian law, including the Geneva Conventions and Additional Protocols I and II, applies to international armed conflicts. These legal instruments provide specific protections for civilians, combatants, prisoners of war, and other affected individuals.

  • Non-International Armed Conflict: The legal framework applicable to non-international armed conflicts primarily consists of Common Article 3 of the Geneva Conventions and Additional Protocol II. These provisions offer minimum protections to all individuals involved in the conflict, irrespective of their affiliation.

3. Threshold of Violence

  • International Armed Conflict: International armed conflicts involve a higher threshold of violence, typically characterized by declared wars, large-scale military operations, and the involvement of regular armed forces of states. The intensity and scale of hostilities tend to be more significant in these conflicts.

  • Non-International Armed Conflict: Non-international armed conflicts encompass a lower threshold of violence, often characterized by internal disturbances, civil wars, or localized clashes. The conflict may involve a range of armed actors, including rebel groups, insurgencies, or other non-state armed entities.

4. Rights and Protections

  • International Armed Conflict: The legal framework governing international armed conflicts provides extensive protection to all individuals affected by the conflict, including civilians, combatants, and prisoners of war. It regulates issues such as targeting, treatment of detainees, and the conduct of hostilities, emphasizing the principles of distinction, proportionality, and military necessity.

  • Non-International Armed Conflict: While the legal framework for non-international armed conflicts offers a lower level of protection compared to international armed conflicts, it still provides fundamental safeguards. Common Article 3 ensures humane treatment for all individuals involved, prohibits torture and cruel treatment, and safeguards the rights of the wounded, sick, and civilians not taking part in hostilities.

5. Recognition and Diplomatic Implications:

  • International Armed Conflict: International armed conflicts are typically recognized as such by the international community, and the parties involved may enjoy certain diplomatic privileges and responsibilities. Treaties and customary international law governing state-to-state relations are often applicable.

  • Non-International Armed Conflict: The recognition and status of non-international armed conflicts can be more complex. While the existence of such conflicts is recognized under international humanitarian law, they may not always receive widespread international recognition. The legal framework primarily focuses on the protection of individuals within the territory of the state experiencing the conflict.


Understanding these differences is essential for determining the appropriate legal framework, rights, and obligations applicable to each type of armed conflict. It guides the actions of states, armed groups, and humanitarian actors in upholding humanitarian principles and ensuring the protection of individuals affected by armed conflicts.


As always, thank you for reading :)


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