1. Below the Threshold: The Law Governing the Use of Force Against Non-State Actors in the Absence of a Non-International Armed Conflict
- Author:
- Daniel Hessel, Julia Shu, and Sarah Weiner
- Publication Date:
- 12-2015
- Content Type:
- Working Paper
- Institution:
- Center for Global Legal Challenges, Yale Law School
- Abstract:
- Boko Haram attacks civilians in Nigeria. The Islamic State launches attacks in Paris. Terrorists take hostages at a hotel in Mali. Mexican drug gangs threaten government officials and civilians. Houthi rebels seek to take control of the government in Yemen—and succeed. States increasingly face security threats from non-state actors, which have led states and observers to ask what states can do in response. What legal framework should apply? What constraints do states face? When can states resort to the use of military force to address threats posed to them by non-state actors, either on their own territory or on the territory of another state? The answer to these questions turns on whether the conflict in question rises to the level of a non-international armed conflict (NIAC). Based on the drafting history of international humanitarian law (IHL) governing NIACs, international jurisprudence, recent state practice, and academic commentary, this paper concludes that a NIAC does not exist unless the conflict passes an intensity threshold. In other words, the intensity of the conflict distinguishes generalized violence involving a non-state actor from a NIAC. Once the existence of a NIAC is established, states participating in it will be governed by relevant IHL. But if states are only governed by the IHL applicable to NIACs once an intensity threshold has been crossed, what law applies below that threshold? The answer varies with the circumstances, depending on whether the state is responding to a threat within its own territory or from outside; and if the threat is from outside the state, whether the host state consents to the use of force against the non-state actor. Thus, to answer the question of what law applies before a NIAC is established, this white paper analyzes three different scenarios in which a state contemplates forceful engagement with a non-state actor. Each scenario presumes that t he non- state actor is organized and has engaged in some violence, but that the intensity of the clash has not crossed the intensity threshold and thus has not risen yet to the level of a NIAC. 1. In Scenario One, a state seeks to engage a non-state actor that operates exclusively within the state’s territorial borders. 2. In Scenario Two, an intervening state seeks to engage a non-state actor located in another state, with the consent of the host state. 3. In Scenario Three, an intervening state seeks to engage a non-state actor located in another state, without the consent of the host state. The analysis of each scenario first identifies the authority that governs whether and when the state may initiate forceful engagement with the non-state actor (the “may the state use force” evaluation), then discusses which legal regime governs the scope and nature of the resulting use of force (the “how may the state use force” evaluation). Different legal regimes govern the acting state’s options in each of the scenarios. Although the authority for action differs, the inquiries for Scenarios One and Two are quite similar. In Scenario One, the acting state may engage the non-state actor with force by virtue of its territorial sovereignty. It must act, however, through a domestic law enforcement framework and in compliance with human rights law. In Scenario Two, the acting state derives the authority to use force against the non-state actor from the host state’s consent. However, it may only rely on that consent insofar as it comports with the host state’s human rights obligations under international law. In raising the possibility of one state violating another state’s territorial integrity, Scenario Three raises a different set of questions. The intervening state’s threat or use of force within another state’s territory is only lawful when authorized by the U.N. Security Council or justified under the Charter’s Article 51 self-defense provision. The intervening state’s use of force is accordingly regulated by the traditional IHL of international armed conflict. Where scenarios overlap (when, for example, the intervening state has both consent and Article 51 authority to act), the acting state may rely on more than one source of authority. It must, however, continue to ensure that it has authority to use force and that its use of force comports with the legal framework appropriate for the nature and intensity of the conflict. It is worth noting at the outset that these scenarios highlight developing areas of international law. Some raise questions that have clear answers in existing legal authority, while others contend with more inchoate legal regimes. Where state practice has not yet solidified into definitive international norms, legal ambiguity remains. In such instances, this white paper notes the existence of ambiguity and examines the history, purposes, and principles of relevant legal regimes to proffer answers.
- Topic:
- Military Strategy, Non State Actors, Law, and Conflict
- Political Geography:
- Global Focus