Acts of Non-State Armed Groups and the Law Governing Armed Conflict

Jonathan Somer
August 24, 2006

The recent conflict in Lebanon and Northern Israel, occurring between a state and a non-state armed opposition group on the territory of a state that has not itself taken up arms, raises distinct challenges for interpretation of international law related to armed conflict. One point of particular complexity is whether the acts of Hezbollah can be attributed to Lebanon, Syria or Iran.[1] Rather than trying to answer such a question in the absence of sufficient facts, this ASIL Insight will outline the general rules of attribution, and then focus on the major implications a finding of attribution would have on the application of international law related to armed conflict: i.e. the separate legal regimes of jus ad bellum (concerning the legality of a resort to armed force) and the jus in bello (concerning conduct during an armed conflict).[2]

The Applicable Law

Rules of attribution form part of what is generally called the law of state responsibility and will affect both the jus ad bellum and the jus in bello. The latter, at least, will in turn affect the scope of individual criminal responsibility for war crimes under international criminal law.

The traditional approach to state responsibility for acts of non-state actors has been laid out by the International Court of Justice (ICJ) in the Nicaragua and Iran Hostages judgments (and in modified form by the Appeals Chamber of the International Criminal Tribunal for the former Yugoslavia(ICTY) in the Tadic [Merits] decision).[3] These are considered "secondary rules" because they determine when the acts of non-state actors will be attributed to a State for the purpose of invoking international obligations (primary norms) governing the conduct of that State. In other words, once the threshold of responsibility is met, the act of the non-state actor will be considered as an act of the State with all the ensuing legal consequences.

There is a substantive difference between legal consequences of (a) attributing a non-state act to a state and (b) a failure of that state to meet due diligence obligations (eg: a duty to prevent terrorism). In the latter case, the state will bear responsibility for the failure to exercise due diligence rather than for the act itself.

In order for an act of a non-state armed group to be attributable to a state, Nicaragua requires "effective control" wherein even 'financing, organizing, training, supplying and equipping" as well as "the selection of its military or paramilitary targets and the planning of the whole of its operation" is not enough to meet the exacting threshold.[4] Tadic relaxes the Nicaragua standard of attribution specifically for acts by non-state military organizations, but still requires "overall control going beyond the mere financing and equipping of such forces and involving also participation in the planning and supervision of military operations."[5] Another way in which conduct of non-state actors can be attributed to a state is if it acknowledges and adopts such actions ex-post facto, as per the reaction by the Khomeini government in Iran after Americans were taken hostage by students unaffiliated with the State. The International Law Commission's Articles on State Responsibility, codifying customary law, recognize both the "control" and the "acknowledgment" bases for state responsibility.[6]


The general international reaction to US acts of self-defence in Afghanistan following the events of September 11, 2001, may have also impacted the rules of attribution. Many legal commentators now consider that the threshold for the secondary rule of attribution to a State for non-state acts has been slackened, at least when it comes to the right of self-defence in response to an armed attack by a non-state actor involved in terrorist activities. Some suggest a standard of due diligence to prevent such activities, while others caution that radical changes to the international legal order could result in the very anarchy that terrorists pursue.[7] An alternative means of assessment (exclusive to the jus ad bellum determination) would be to apply the primary customary rule of "substantial involvement" as enumerated in Article 3(g) of UN General Assembly Resolution 3314 on the definition of aggression.[8]

Effect of Attribution on Jus Ad Bellum

The UN Charter limits the use of force to collective security authorized by the Security Council under Chapter VII and self-defence in reaction to an "armed attack" as contemplated by Article 51. While the post-September 11th consensus is that the Charter does not require the armed attack to be attributable to a State in order to invoke the right to self-defence, the problem is that attacking a non-state actor will almost inevitably require military operations on the sovereign territory of a State. If that State does not give its consent, then any use of force on its territory will be an illegal use of force according to the traditional Charter system. The increasing capacity of non-state actors to launch "armed attacks" against a State challenges the continued relevancy of a strict Article 51 interpretation.


Under a strict interpretation of Article 51, Israel's use of force in Lebanon's territory is problematic if the acts of Hezbollah cannot be attributed to any state or if the acts of Hezbollah are attributable to either Syria or Iran. In both cases, Israel's campaign in Lebanon would only be legal under an expanded interpretation of the right to self-defence.[9]

Effect of Attribution on Jus in Bello

The jus in bello, or international humanitarian law (IHL), is divided into two legal regimes: the first covers international armed conflict between two States, while the second covers non-international armed conflict between a State and a non-state actor, or between two (or more) non-state actors. Common Article 3 of the Geneva Conventions relating to non-international armed conflict is one of the earliest norms of international law to impose obligations on both state and non-state entities.[10] In spite of a recent general trend toward conforming the law of non-international armed conflict to the more protective regime of international armed conflict, States still maintain a distinction due to traditional considerations of sovereignty.

A determination of attribution will affect the classification of the conflict. If the acts of Hezbollah are deemed attributable to a state, the conflict is considered to be international and the Geneva Conventions will apply in their entirety. Otherwise, Common Article 3 will be the governing regime. In both cases, the principles of Protocol I to the Geneva Conventions, on the conduct of hostilities, generally apply by nature of their customary law status, even though Israel is not party to the Protocol.[11] A further complication is the potential existence of a parallel international armed conflict between Lebanon and Israel. Although Common Article 2 (on the scope of application of the Geneva Conventions) covers only conflict between High Contracting Parties (i.e.: States), it also applies when there has been a partial or total occupation of a High Contracting Party (even when that occupation meets with no resistance from the State). Therefore, even though Lebanon may not have been engaged in an armed conflict with Israel, the Geneva Conventions at least apply to any occupation of southern Lebanon. An argument also exists which claims that the conflict is international in nature, not as a result of any issue of attribution or occupation, but simply because Common Article 2 applies as soon as Israel attacked Lebanese territory.

The classification of the conflict impacts the application of IHL. In international armed conflict, IHL applies immediately at the commencement of hostilities or occupation. Yet the situation is more complex in non-international armed conflict, where the level of intensity must be beyond "internal disturbances and tensions." There is competing jurisprudence on whether the duration of violence is legally significant. According to the ICTY Tadic decision on jurisdiction, "protracted armed violence" is required in order to launch the application of IHL in non-international armed conflict, while the Inter-American Commission in Tablada has invoked the law of non-international armed conflict to a conflict lasting only several hours.[12] Therefore, whether incidents at the start of the conflict are covered by IHL may depend on the classification of the conflict.

A significant consequence of attributing Hezbollah acts to a State would be that each party to the conflict would be bound to grant Prisoner of War (POW) status to captured enemy combatants who meet the criteria of Article 4(A)(1) or (2) of Geneva Convention III.[13] Israeli soldiers, as members of the regular army, would be automatically entitled to POW status under 4(A)(1), while Hezbollah fighters would probably have to meet the conditions of Art. 4(A)(2) as members of "other militia" in order to be granted POW status. All POWs must be released at the end of hostilities on a non-reciprocal basis. These rules would apply to the treatment of the two Israeli soldiers whose abduction triggered the beginning of hostilities, unless it could be argued that Article 4 applies only to members of the armed forces captured during the conflict.

The classification of the conflict also affects how and when an individual can be prosecuted for war crimes. First, grave breaches of the Geneva Conventions (such as extensive destruction of property, but only if the destruction is not justified by military necessity and is carried out unlawfully and wantonly) can only be committed in international armed conflict. The universal jurisdiction component of the grave breach regime requires that all State parties have an obligation to prosecute or extradite suspected perpetrators, regardless of where the breach took place. This means that the US would have mandatory jurisdiction over an Israeli soldier or Hezbollah fighter visiting New York for alleged grave breaches committed in Lebanon, but only in the case of international armed conflict. Second, international criminal law covers individual responsibility for "non-grave" breaches of many of the substantive provisions of the Geneva Conventions and customary laws of war to a greater extent in international armed conflict than in non-international conflict. In fact, prior to the 1995 ICTY Tadic Appeal decision on jurisdiction, it was commonly held that war crimes did not exist in non-international armed conflict at all. The difference is alluded to by the fact that the Statute of the International Criminal Court (ICC) lists 26 war crimes for international armed conflict, while only 12 for non-international.[14] With respect to the Lebanon conflict, it is significant to note that intentionally launching a disproportionate attack attracts individual criminal responsibility only in international armed conflict. Finally, it may also be mentioned that the ICC jurisdictional threshold for certain categories of war crimes in non-international armed conflict requires "protracted armed conflict." Whether or not protracted "conflict" represents a higher threshold than protracted "violence' as discussed above, the temporal standard (requiring that the conflict or violence be "protracted") has become an unequivocal pre-condition for individual responsibility under the ICC.[15]

In conclusion, this post-modern conflict involving a "state-like apparatus inside a State" is another in a stream of examples illustrating the challenges non-state actors are posing to the traditional construction of international law. A determination of state attribution for acts committed by Hezbollah would have effects resonating beyond Israel's right to self-defence. It would also influence the extent to which belligerents on both sides of the conflict can be held responsible both as entities and individuals, and may put further strains on the humanitarian-oriented separation of jus in bello from jus ad bellum.









About the author

Jonathan Somer ( is an international humanitarian law delegate with the Danish Red Cross, and an LL.M. candidate at the University Centre for International Humanitarian Law in Geneva. He has previously worked for the OSCE in former-Yugoslavia.

Thanks to Andrew Carswell, Drazan Djukic, Lindsey Cameron and Marco Sassòli for their helpful comments. Any errors are attributable, of course, to the author.


[1] For example, Likud Party leader Benjamin Natanyahu has called Hezbollah "an Iranian Army division" fighting in a war "conceived, organized, trained and equipped by Iran." Steven Erlanger, "In Late Drive, Israel Seeks Outcome that looks like Victory", International Herald Tribune, August 14, 2006, p.5; The Independent reports that Israel claimed Lebanon was responsible for the initial Hezbollah attack. See Robert Fisk, "In the Face of Bush's Lies, It's Up to Assad to Tell the Truth", The Independent, August 16, 2006.

[2] A fundamental principle of international law is the separation between jus ad bellum and jus in bello. It is considered that in order to maximise protection for those not taking part in hostilities, jus in bello must be applied equally to both sides of a conflict regardless of which side is 'just'- in almost any conflict both sides will claim to be the party acting in conformity with jus ad bellum.

[3] Case Concerning the Military and Paramilitary Activities in and Against Nicaragua (Nicaragua v. United States of America), 1986 ICJ 14, 25 Int'l Legal Materials 1023 (1986) (Judgment of 27 June 1986); United States Diplomatic and Consular Staff in Tehran (United States v. Iran), 1980 ICJ 3, 19 Int'l Legal Materials 553 (1980) (Judgment of 24 May 1980); The Prosecutor v. Dusko Tadic, IT-94-1-A, ICTY Appeals Chamber, 38 Int'l Legal Materials 1518 (1999) (Judgment of 15 July 1999) (Merits).

[4] Nicaragua, supra note 3, at para. 115.

[5] Tadic, supra note 3, at para. 145.

[6] Articles 8 and 11, in UN General Assembly Res. 56/83, Annex (2001), and see James Crawford, The International Law Commission's Articles on State Responsibility 110-113, 121-123 (2002).

[7] For due diligence, see: Robert. P. Barnidge Jr., "State's Due Diligence Obligations with Regard to International Non-State errorist Organisations: The Heavy Burden States Must Bear,"16 Irish Studies in International Afairs120 (2005). For a cautious approach, see: Antonio Cassese, "Terrorism is Also Disrupting Some Crucial Legal Categories of International Law,"12 European Journal of International Law 993-1001 01).

[8] This requires that the threshold of aggression be higher than that of "armed attack" as contained in Article 51 of the UN Charter, a point which remains controversial. Resolution 3314, Article 3 states: "Any of the following acts, regardless of a declaration of war, shall, subject to and in accordance with the provisions of article 2, qualify as an act of aggression:"(g) The sending by or on behalf of a State of armed bands, groups, irregulars or mercenaries, which carry out acts of armed force against another State of such gravity as to amount to the acts listed above, or its substantial involvement therein."

[9] It is arguable that a parallel customary right to self-defence exists without the need of a previous armed attack, if the need to act in self-defence is instant and overwhelming. See The Caroline incident, reported in 2 J. Moore, Digest of Int'l Law 409 (1906), and the post-World War II judgment of the International Military Tribunal at Nuremberg, 22 Trial of the Major War Criminals Before the International Military Tribunal 448-450 (1948).

[10] International law is traditionally based on relationships between states. The last half of the 20th century saw a trend in which other entities, such as individuals and international organisations, gained limited legal personality.

[11] There is debate as to the extent to which the customary rules covering the conduct of hostilities is the same in international and non-international armed conflict. The recently published ICRC study on Customary Law suggests that differences are in most cases not significant (with the possible exception of environmental damage). See Jean-Marie Henckaerts & Louise Doswald-Beck, Customary International Humanitarian Law, Vol. 1: Rules (2005).

[12] Prosecutor v. Dusko Tadic, IT-94-1-AR72, ICTY Appeals Chamber, 2 October 1995 (Jurisdiction) par. 70; Inter-American Commission on Human Rights, Report No. 55/97, par. 154-156.

[13] Art. 4(A): "Prisoners of war, in the sense of the present Convention, are persons belonging to one of the following categories, who have fallen into the power of the enemy:

1. Members of the armed forces of a Party to the conflict as well as members of militias or volunteer corps forming part of such armed forces.

2. Members of other militias and members of other volunteer corps, including those of organized resistance movements, belonging to a Party to the conflict and operating in or outside their own territory, even if this territory is occupied, provided that such militias or volunteer corps, including such organized resistance movements, fulfil the following conditions:

(a) That of being commanded by a person responsible for his subordinates;

(b) That of having a fixed distinctive sign recognizable at a distance;

(c) That of carrying arms openly;

(d) That of conducting their operations in accordance with the laws and customs of war."

[14] The ICC Statute is an indication, rather than an expression, of customary law pertaining to war crimes. While none of the relevant States is a party to the ICC Statute, the Statute could nevertheless be invoked under certain conditions. See art. 12(3), which would permit the Court to exercise jurisdiction if a non-party State on whose territory the conduct occurred formally accepts the Court's jurisdiction with respect to the crime in question.

[15] See ICC Statute Art. 8(2)(f).