When and or does the law of non-international armed conflict apply? Since most contemporary armed conflicts are between states and organized armed groups, or between such groups, these are important questions for international lawyers and policy makers alike. The answers may affect the jurisdiction of US military commissions, the detention of Taliban commanders and ISIL members, legal constraints on Saudi-led military operations in Yemen, and accountability for war crimes in Syria.
In this article, I will discuss the Non-International Armed Conflict (NIAC) Trigger and Threshold. My starting point is the much discussed Commentary 2016 on the First Geneva Convention published recently by the International Committee of the Red Cross (ICRC). The University of Georgia Law School recently hosted a fantastic event examining a number of issues raised by the commentary, including the duty to “enforce” the Convention by other parties, accidental damage to sick and wounded fighters, and the classification of conflicts. This message was born from this rich discussion.
The ICRC commentary makes it clear that an international armed conflict (IAC) “may arise when a State unilaterally uses armed force against another State even if the latter does not or cannot respond by military means”. Accordingly, the law of armed conflict limits the first resort to armed force by one state against another. Let’s call it a unilateral trigger.
Also there are no requirement that the use of armed force between the Parties reaches a certain level of intensity before it can be said that a [international] an armed conflict exists. Accordingly, minor skirmishes between state armed forces, or the capture of a single soldier, “would trigger an international armed conflict and lead to the applicability of humanitarian law.” Let’s call it a nominal threshold.
Unfortunately, the Commentary is not so clear with regard to non-international armed conflicts. The Commentary endorses the view that NIACs “are protracted armed clashes between government armed forces and … one or more armed groups, or between such groups”. This passage, as well as certain quotes authority, seem to suggest a bilateral trigger, requiring “armed confrontations”, “combat zones” or, simply, “combats”.
The commentary also states that, for the NIAC law to apply, “[t]he armed confrontation must reach a minimum intensity level.” Read alongside the discussion of the IAC Commentary, it seems that this “minimum level of intensity” would not be achieved by minor skirmishes or the capture of a single soldier or combatant.
The Commentary seems to accept a unilateral trigger and a nominal threshold for the ACI (quadrant 1) but a bilateral trigger and a significant threshold for the NIAC (quadrant 4).
In my opinion, we should accept a unilateral trigger and a nominal threshold for CAIs and NIACs.
First, if an armed group is sufficiently organized, a first use of armed force by or against that group should trigger a NIAC. Consider the following case:
Daesh: Daesh fighters invade the Syrian-Iraqi border, killing Iraqi civilians, capturing Iraqi territory and taking control of Iraqi government institutions. Iraqi forces flee, offering no resistance.
If we accept a bilateral trigger for NIACs, then the law of armed conflict does not apply until Iraqi forces “respond”.[s] by military means”, resisting the advance of Daesh. Until then, Daesh fighters do not violate the law of armed conflict and do not commit war crimes. This result seems deeply unattractive. Although Daesh fighters violate Iraqi criminal law, it seems difficult to accept that they do not violate the law of armed conflict.
Now consider the following scenario:
Consent: State A attacks organized armed group G on the territory of State T, with the consent of State T. There is no pre-existing armed conflict between State A and group G. L State A fails to take feasible precautions in the attack and recklessly kills many people. civilians.
If we accept a bilateral trigger for NIACs, then the NIAC law does not apply until Group G responds with military force, resulting in “armed confrontations”. Since State T consents to this, the law of the IAC also does not apply. It follows that State A is not violating the law of armed conflict and is not committing war crimes. This result seems intolerable.
It is important to note that human rights law may not be sufficient to protect civilians or armed forces in cross-border cases such as those described above. According to most views, human rights law does not apply to the behavior of non-State armed groups that not yet exercise territorial control and perform government-like functions. Moreover, according to some militarily active states, human rights law does not prevent lethal extraterritorial targeting by state armed forces. Yet, in my view, such behavior should be limited by international law.
We should also only accept a nominal current threshold for NIACs. Consider the following case:
Capture: Members of organized armed group G mistakenly cross the unmarked border between State T, in which they normally operate, and State A. They encounter a unit of soldiers from State A, and a minor skirmish s then. No one is killed, but one member of the group is captured by the soldiers while one soldier is captured by the group and taken back across the border to State T.
In this case, it seems that both the group member and the soldier should be entitled to human treatment under Article 3 common to the Geneva Conventions. Additionally, if there are civilians present when the skirmish occurs, then it appears that the conduct of the skirmish should be limited by customary rules, including distinction, precautions, and proportionality If these rules are flagrantly violated, these violations should constitute war crimes.
In my opinion, if an organized armed group has the ability to support military operations then any military operation by or against this group should be limited by the law of armed conflict. The organization and capacity of the group are sufficient to distinguish military operations by or against the group from “internal disturbances and tensions, such as riots, isolated and sporadic acts of violence and other acts of the same nature.”
Some might fear that the application of the law of armed conflict to the first uses of low-intensity force will displace or reduce the protections of human rights law. Fortunately, this is not the case. Even during armed conflict, states may choose not to derogate from their ordinary human rights obligations. Alternatively, a waiver can be strictly required only with respect to certain measures, or only in certain parts of a State’s territory, or only in certain situations, even if the law of armed conflict provides additional constraints for all acts having a sufficient connection with the conflict.
More importantly, killings that are not prohibited by NIAC law may be prohibited by human rights law. Specifically, “[w]here, military necessity does not compel the parties to an armed conflict to resort to lethal force…, but allows for example that the target is captured rather than killed, respect for the right to life can be better ensured by pursuing this option. In situations of armed conflict, NIAC law can facilitate the interpretation of human rights law but does not exhaust the content of human rights law.
Finally, the law of armed conflict cannot authorize what human rights law prohibits. As the ICRC notes somewhere else, “[t]he law on the conduct of hostilities is above all a law of prohibition: it does not authorize, but prohibits certain things. Human rights law and NIAC law do not conflict but complement each other, as they both impose constraints on violence rather than permits to commit violence. Like Additional Protocol II makes it clear that human rights law “offers[s] basic protection to the human person” while the CANI law aims “to ensure better protection for the victims of  armed conflicts”.