Categories of Armed Conflicts in International Humanitarian Law (IHL)

International Humanitarian Law (IHL), also referred to as the law of armed conflict, governs the conduct of hostilities and the protection of persons during times of armed conflict. One of its key functions is to classify armed conflicts because the rights and responsibilities of parties, as well as the protections afforded to combatants and civilians, can vary depending on the type of conflict. The two principal categories of armed conflicts under IHL are International Armed Conflicts (IACs) and Non-International Armed Conflicts (NIACs).

1. International Armed Conflicts (IACs)

International armed conflicts are governed primarily by the Geneva Conventions of 1949 and their Additional Protocol I (1977). These apply in any conflict between two or more states, regardless of whether a formal declaration of war has been made.

Definition: An IAC exists whenever there is a resort to armed force between two or more sovereign states. This is the most straightforward type of armed conflict, and it is presumed to exist whenever there is military engagement between states.
Scope of Application:
- The Geneva Conventions and Additional Protocol I provide comprehensive rules for the protection of wounded and sick soldiers, prisoners of war, and civilians.
- IACs also include wars of national liberation in which peoples are fighting against colonial domination, alien occupation, or racist regimes in the exercise of their right to self-determination. These conflicts, while not traditional state-versus-state wars, are recognized as IACs under Article 1(4) of Additional Protocol I.
Key Principles and Rules:
- Distinction: Parties must always distinguish between combatants and civilians.
- Proportionality: Attacks must not cause excessive civilian harm in relation to the anticipated military advantage.
- Necessity: Force must only be used to achieve legitimate military objectives.
- Humanity: Suffering must not be excessive, and unnecessary cruelty is forbidden.
Combatant Status and Prisoners of War (POWs): Combatants in IACs are afforded combatant immunity for lawful acts of war and are entitled to prisoner-of-war status if captured. POWs are protected under the Third Geneva Convention, which mandates humane treatment and specific conditions for their internment.
Occupied Territories: The law of occupation, governed by the Fourth Geneva Convention and Additional Protocol I, applies when a territory is placed under the control of a hostile foreign state. It sets out protections for the civilian population in occupied territories and establishes the duties of the occupying power.

2. Non-International Armed Conflicts (NIACs)

Non-international armed conflicts are typically governed by Common Article 3 of the Geneva Conventions and Additional Protocol II (1977). These types of conflicts occur within the territory of a single state and involve either state forces and non-state armed groups or conflicts between non-state armed groups.

Definition: NIACs occur when there is protracted armed violence between government forces and organized armed groups, or between such groups within a state. The threshold for NIACs is higher than mere internal disturbances or tensions (e.g., riots or isolated acts of violence). There must be a minimum degree of organization on the part of the armed groups and sustained intensity of fighting.
Scope of Application: The rules for NIACs are more limited compared to those governing IACs. However, Common Article 3, often referred to as a "mini-convention," provides basic guarantees, such as:
- Humane treatment of persons not taking active part in hostilities, including fighters who have laid down their arms.
- Prohibition of murder, torture, cruel treatment, and outrages upon personal dignity.
- Prohibition of the taking of hostages.
- Fair trial guarantees for those detained.
Additional Protocol II: This protocol further elaborates on the protection of persons in NIACs, but its applicability is limited to conflicts that meet certain higher thresholds, including the control of territory by non-state actors that allows them to carry out sustained military operations.
Internal Disturbances and Tensions: Situations of internal disturbances, such as riots or isolated and sporadic acts of violence, do not qualify as NIACs. These situations are typically governed by domestic law and human rights law, rather than IHL.

3. Other Situations

While the two principal categories of armed conflict under IHL are IACs and NIACs, there are some additional nuances and emerging types of conflicts that are relevant under modern IHL interpretations:

Mixed Conflicts or "Transnational" Conflicts: Some conflicts involve cross-border elements but do not fit neatly into the traditional IAC/NIAC distinction. For example, conflicts between a state and non-state armed groups that operate across national borders, such as certain terrorism-related conflicts, raise complex classification questions. These conflicts may require a combination of NIAC and IAC rules depending on the context.
Internationalized Internal Conflicts: An internal conflict (NIAC) may become "internationalized" when one or more foreign states intervene on behalf of either the government or the non-state armed group. When this occurs, parts of the conflict may be governed by the laws of IACs if state forces are directly involved in hostilities against another state's forces.
Armed Conflicts Involving Terrorist Groups: The rise of terrorist organizations as key players in modern armed conflicts, such as ISIS, has raised questions about the classification of these conflicts. In general, if a terrorist group has sufficient organization and conducts sustained military operations, the conflict may be classified as a NIAC. However, counterterrorism operations conducted by states in foreign territories could trigger the rules of IACs if the territorial state's government is involved.

4. Principles and Protections Common to All Armed Conflicts

Regardless of whether a conflict is classified as an IAC or NIAC, several core principles under IHL apply across the board:

Protection of Civilians: Civilians must be protected from the effects of hostilities, and all feasible precautions must be taken to avoid harming them.
Prohibition of Targeting Non-Combatants: Combatants must not direct attacks against civilians, civilian objects, or those who are hors de combat (e.g., wounded soldiers or prisoners of war).
Prohibition of Torture and Other Cruel Treatment: Both in IACs and NIACs, torture and inhuman treatment are absolutely prohibited, without exception, under Common Article 3 and Customary International Law.
Treatment of the Wounded and Sick: Combatants who are wounded or sick, regardless of their affiliation, must be cared for, and medical personnel and facilities must be protected from attack.
Prohibition on the Use of Indiscriminate Weapons: Weapons that cannot distinguish between combatants and civilians, or that cause unnecessary suffering, are prohibited in all armed conflicts.

5. Challenges in Modern Armed Conflict Classifications

In contemporary conflicts, the classification of armed conflicts has become more challenging due to:

Hybrid Warfare: States and non-state actors may employ a combination of conventional and unconventional tactics, cyber warfare, propaganda, and irregular combat forces, making it difficult to draw clear distinctions.
Use of Private Military and Security Companies (PMSCs): The involvement of private contractors in hostilities can complicate the classification of a conflict, as they may not fall neatly into the traditional categories of state or non-state actors.
Cyber Warfare: IHL is still adapting to new domains of conflict, such as cyber warfare, which could occur without direct physical violence but still cause significant harm to states or civilians.

6. Conclusion

In summary, the classification of armed conflicts under International Humanitarian Law is essential for determining the applicable legal regime and the protections afforded to individuals. The key distinction is between International Armed Conflicts (IACs), which involve conflicts between states, and Non-International Armed Conflicts (NIACs), which involve armed violence between a state and non-state actors or among non-state actors. Despite the complexity of modern warfare, the core principles of IHL—such as the protection of civilians and the humane treatment of all persons—remain at the heart of the law, guiding the conduct of hostilities and safeguarding human dignity in the midst of armed conflict.