Ilaria Infante (Università della Campania “Luigi Vanvitelli”)

1. On 9 September 2020 the German Federal Government announced the decision to extend the military operation against the so-called Islamic State of Iraq and the Levant (ISIL or IS) in Iraq and Syria until 31 January 2022. On 29 October 2020 the German Parliament (Bundestag) approved the mandate’s extension. In its formal request to the Bundestag, the Federal Government acknowledged that in March 2019 the Anti-IS Global Coalition had successfully regained control over the areas in Iraq and Syria formerly controlled by ISIL. Nonetheless, the Government affirmed that the IS continues to have the resources, military means and the will to exercise territorial control over the areas formerly controlled and it is still able and willing to carry out attacks in Syria, Iraq, Europe and beyond. For these reasons, according to the Government, Germany could still invoke, as a legal basis for the operation, the right of collective self-defence against ISIL in application of Article 51 of the United Nations Charter.

This argument seems to deepen the position expressed by the German Federal Constitutional Court in its Order of 17 September 2019. On that occasion, the Court was asked to decide on the legality of Germany’s military operation in Iraq and Syria (which began in December 2015) and, among questions of constitutional law, it addressed the debated problem of self-defence against non-State actors. The Court considered tenable to argue that such a right could be exercised, but only if non-State actors have a territorial consolidated basis.

It seem appropriate, therefore, to analyse Germany’s position on self-defence against non-State actors and try to establish where it stands among the international law positions on the topic, in particular in relation to the much disputed unwilling or unable doctrine. According to this doctrine, in fact, the right of self-defence can be exercised on the territory of any State unwilling or unable to prevent attacks by non-State actors operating from that territory.

2. On 13 November 2015, members of ISIL carried out terrorist attacks in Paris, causing 130 deaths.

After this tragic event, France claimed to be the victim of an armed aggression and affirmed that its already ongoing military operation in Syria from then on would be characterised as individual self-defence (UN Doc. S/PV.7565).

The United Nations Security Council Resolution 2249 of 20 November 2015 condemned ISIL’s terrorist attacks and called upon Member States «that have the capacity to do so to take all necessary measures, in compliance with international law, in particular with the United Nations Charter, as well as international human rights, refugee and humanitarian law, on the territory under the control of ISIL […] in Syria and Iraq, to redouble and coordinate their efforts to prevent and suppress terrorist acts committed specifically by ISIL […] and to eradicate the safe haven they have established over significant parts of Iraq and Syria»(UN Doc. S/RES/2249(2015), point 5).

Moreover, during the meeting of the Council of the European Union on 17 November 2015, France obtained for the first time the activation of the mutual defence clause of Article 42(7) of the Treaty on European Union (TEU), according to which «[i]f a Member State is the victim of armed aggression on its territory, the other Member States shall have towards it an obligation of aid and assistance by all the means in their power, in accordance with Article 51 of the United Nations Charter».

Acting upon these provisions, the German Federal Government declared its support to France and therefore, on 1 December 2015, decided to deploy soldiers of the German armed forces (Bundeswehr) in the Iraqi and Syrian territories occupied by ISIL. In relation to the legal basis of this decision, the German Government affirmed that the deployment of soldiers was pursuant to Article 24(2) of the Basic Law (Grundgesetz) – according to which the Federal Republic of Germany may enter into a system of mutual collective security – and Article 51 of the UN Charter, as an exercise of the right of collective self-defence in support of France, Iraq and the US-led international coalition against ISIL. Three days later, on 4 December 2015, the German Bundestag authorised the deployment and the operation began on 6 December 2015. The mandate was initially meant to last until 31 December 2016, but it was then extended annually by subsequent decisions of the Bundestag, with the latest annual extension until 31 October 2019. Then, after two six-month extensions on 24 October 2019 and 25 March 2020, the Parliament decided to extend the military operation until 31 January 2022.

After the deployment of its armed forces, the German Federal Government reaffirmed its exercise of the right of collective self-defence against ISIL in its letter to the Security Council of 10 December 2015. Germany specified that the measures were taken against the terrorist organization and not against the Syrian Arab Republic. It did so because, while the Iraqi Government had expressly made a request for assistance, Syrian authorities had repeatedly contested the military intervention of the international coalition. In particular, the letter said that, because ISIL had occupied a part of the Syrian territory over which the Syrian Government did not, at the time, exercise effective control, «States that have been subjected to armed attack by ISIL originating in this part of Syrian territory, are therefore justified under Article 51 of the Charter of the United Nations to take necessary measures of self-defence, even without the consent of the Government of the Syrian Arab Republic» (UN Doc. S/2015/946).

On 31 May 2016 the German parliamentary group DIE LINKE filed an application to the Federal Constitutional Court claiming that the Federal Government and the Bundestag had violated the Bundestag’s rights under Article 24(2) in conjunction with Article 59(2) first sentence of the German Basic Law. Under these two provisions, Germany’s participation in a system of mutual collective security requires a statutory act of approval by the German Bundestag, conferring upon the latter the right to participate in decisions concerning Germany’s rights and obligations under an international treaty.

According to the applicant, the rights of the Bundestag deriving from the above mentioned Articles of the Basic Law were violated since deploying armed forces in the territory of a State to which the conduct of a non-State actor is not attributable fundamentally extended or modified the framework of Germany’s rights and obligations under the UN Charter.

3. In its Order of 17 September 2019 the Constitutional Court found the application inadmissible, arguing that the applicant had failed to sufficiently substantiate the alleged violation of constitutional rights of the Bundestag. The Court did so primarily by invoking procedural elements of the German Law. However, it also touched upon issues of international law. Dealing with the applicant’s assertion that Germany’s deployment of its armed forces breached the purposes and the fundamental principles of the United Nations, the Constitutional Court affirmed that the German operation did not violate the UN Charter.

The Court first contended that the Security Council had called on Member States to take necessary measures in accordance with international law on the territories under the control of ISIL in Syria and Iraq.

From this perspective, the measures undertaken by the Member States would simply respond to the emerging phenomenon of an international terrorist group operating from a third-State territory; they would, in other words, still fall within the purpose, stated in Article 1 of the UN Charter, «to maintain international peace and security, and to that end […] take effective collective measures for the prevention and removal of threats to the peace».

In its subsidiary submission, the applicant had argued that the limits of the Act of Accession of the Federal Republic of Germany to the UN Charter were exceeded since the German government had provided an untenably broad interpretation of Article 51 of the UN Charter, not in accordance with current international law. On this argument, the Court noted that Security Council Resolution 2249 could still provide a sufficient legal basis for the deployment of German soldiers, without making the invocation of Article 51 of the UN Charter necessary in the present case. In any manner, the Court added that the Federal Government and the Bundestag’s interpretation of the same Article was not untenably broad. While acknowledging that the interpretation of Article 51 had been at the centre of debates since its adoption, the Court affirmed that its wording would not prevent States from treating non-State actors as aggressors and from prohibiting measures of self-defence which could affect third States in whose territory non-State actors operate. According to the Court, this interpretation of Article 51 would not conflict with its object and purpose, as its ultimate aim would be to ensure that UN Member States, without prejudice to the prohibition of the use of force, can defend themselves against attacks, regardless of the identity of the aggressor. Hence, and in light of this purpose, the Court argued that it would be at least tenable to consider as permissible grounds of self-defence attacks by territorially consolidated (territorial verfestigte)non-State actors.

The Federal Constitutional Court concluded that this interpretation would not even be in contrast with the decisions of the International Court of Justice (ICJ) regarding the right of self-defence. In fact, according to the Constitutional Court, while, in the past, the ICJ had interpreted Article 51 restrictively (Nicaragua v. United States Judgment, 1986, para.195; Construction of a Wall in the Occupied Palestinian Territory, Advisory Opinion, para. 139), in its more recent decisions it had avoided to determine clearly whether the right of self-defence could be invoked, not directly against a State, but against non-State actors operating from that State’s territory (Congo v. Uganda Judgment, para. 147).

The German Court made indeed reference to the reasoning expressed by Judges Kooijmans and Simma’s separate opinions in the Congo v. Uganda case and by Judge Buergenthal’s declaration inthe Construction of a Wall opinion,which suggested a less restrictive interpretation of Article 51 and the applicability of the right of self-defence in such cases. It must be noted, however, that these opinions, while being authoritative, are not legally binding as such.

4. In response to the German Constitutional Court’s argument that the Security Council Resolution 2249 could provide a sufficient legal basis,  it must be noted that such Resolution was not expressly adopted under Chapter VII of the UN Charter, nor did it authorise military measures in the exercise of the right of self-defence. It merely called upon all Member States to take all the necessary measures complying with international law. This omission is notable if compared with other Security Council resolutions often invoked for a broad interpretation of self-defence, like Resolution 1368 of 12 September 2001, which explicitly mentioned self-defence in its preamble.

Second, in relation to the interpretation of Article 51 of the UN Charter, it seems to us that the Court chose to explicitly refer to non-State actors which are territorially consolidated in order not to deal with the unwilling or unable standard put forward by some States participating in the military operation against ISIL in their letters to the Security Council (see letters from: United States (UN Doc. S/2014/695); Canada (UN Doc. S/2015/221); Australia (UN Doc. S/2015/693); and Turkey (UN Doc. S/2015/563)).

According to the unwilling or unable doctrine (see e.g. Deeks), a State that is victim of attacks by non-State actors operating from the territory of another State must ascertain whether the territorial State is willing and able to put an end to the threat posed bynon-State actors before using force in the territorial State and without its consent. Should the territorial State be unwilling or unable to prevent such attacks, the victim State would have a right to use force in the exercise of self-defence.

Germany did not invoke this doctrine directly but implicitly referred to it in its letter of 10 December 2015 to the UN Security Council. On that occasion, this State affirmed that the right of collective self-defence applied to the case at hand because Syria did not, at the time, exercise effective control on the part of its territory occupied by ISIL.

However, it is unclear whether, according to the unable doctrine, the loss of effective control over part of territory would automatically amount to a State’s inability. As Starski has noted, «the idea of ‘ungoverned spaces’ […] seems to refer to a subcategory of a State’s inability based on an ineffective exercise of its territorial control in certain limited areas hence being narrower than the ‘unwilling or unable’ standard».

The German Constitutional Court did not address the unwilling or unable doctrine and, conducting a reasoning in general terms, merely observed that a territorial State exercises, at best, limited control over the part of its territory where non-State actors operate in a consolidated manner. Arguably, the Court did so as a form of judicial self-restraint, since it was not directly called to deal with this doctrine to decide the case. Furthermore, sustaining that position would have significantly lowered the threshold of Article 51.

After the events of 9/11 an increasing number of commentators have argued that self-defence can be invoked against non-State actors operating from the territory of a State (see for example: Trapp, “Can Non-State Actors Mount an Armed Attack?”; Moir, “Action Against Host States of Terrorist Groups”, bothin Weller, p. 679 ss. and p.720 ss.). There have also been cases of States claiming self-defence against non-State actors (e.g. Israel against Hezbollah in Lebanon in 2006), albeit this practice remains controversial (Gray, p. 200 ss.). The reason is twofold. First, the invocation of self-defence against non-State actors poses problems with the right of the host State to territorial sovereignty; second, Article 2(4) of the UN Charter prohibits the use of force only in international relations, that is between States, and does not refer to non-State actors.

A more restrictive reading of Article 51 is still preferable and it is sustained by both  the relevant provisions and  case-law. Indeed, according to Article 51 of the UN Charter, a right to self-defence, individual or collective, can be recognized only «if an armed attack occurs». Scholars have disputed whether only States or also non-State actors could commit armed attacks. In this regard, even if Article 51 does not refer expressly to a State armed attack, the inter-State dimension can be deduced by the combined reading of this Article with Article 2(4) of the UN Charter. Moreover, although the Charter does not provide for a definition of armed attack, some statements in the travaux préparatoires equated the term aggression and armed attack. The ICJ has also overlapped the two concepts (Gray, op. cit, p. 120 ss. For a contrary position, according to which the two notions do not necessarily fully coincide and that armed attack is the narrower concept of the two see e.g. Nolte and Randelzhofer, “Article 51”, in Simma et al., p. 1397 ss.). In affirming that «[t]here appears now to be general agreement on the nature of the acts which can be treated as constituting armed attacks» (Nicaragua v. United States,para. 195), the Court has indeed quoted the 1974 UN General Assembly Resolution 3314 (XXIX) on the Definition of Aggression. This Resolution is considered to be reflective of customary international law and affirms, in its Article 1, that aggression is «the use of armed force by a State against the sovereignty, territorial integrity or political independence of another State». The inter-State character of an act of aggression was later confirmed by the International Criminal Court (ICC) Conference of Kampala in 2010, which made explicit reference to the aforementioned Article 1 of Resolution 3314 and affirmed that the perpetrator of the crime of aggression must be a person «in a position effectively to exercise control over or to direct the political or military action of a State», thus excluding individuals of non-State groups.

While according to Article 3(g) of Resolution 3314 even «the sending by or on behalf of a State of» irregular groups into the territory of another State or «its substantial involvement» in the use of force by these groups would qualify as an act of aggression, the tolerance, the acquiescence or even the mere support by a State do not amount to armed attack (see e.g.: Nicaragua v. United States, para. 247).

Equating the terms aggression and armed attack would thus results in the inter-State character of the latter too. This means that only the substantial involvement of a State in the attack by irregular groups would give another State the right to act in self-defence. It follows that the threshold of Article 51 of the UN Charter is very high.  Therefore, a State that suffers a terrorist attack may react in self-defence using force in the territory of another State only if the situation falls under the cases of Article 3 of Resolution 3314; otherwise, in order not to breach the prohibition on the use of force, it would need the consent of the State on whose territory the terrorists operate.

Indeed, even if the actions of the victim State were to be directed against the non-State armed group, no matter how temporary and limited they might be, they would still result in a violation of the sovereignty and territorial integrity of the host State within the meaning of Article 2(4) of the UN Charter.

In the case of ISIL, not only were Syria not in any way substantially involved with the terrorist group but it also tried to fight and suppress it, however unsuccessfully, even before the start of the military operations of the other States on its territory.

To broaden the interpretation of Article 51 well beyond its meaning with the adoption of the unwilling or unable standard would lead, in the case of Syria, to the paradoxical situation that even the objective inability of a State to eradicate non-State actors operating on its territory would trigger the threshold of Article 51 (as argued in general by Corten).

A victim State should not be entitled to use force within the territory of another State only because that State is unable to prevent non-State actors’ attacks originating from its territory. Mere inability to respond to the threat posed by non-State actors does not constitute a violation of the principles of jus ad bellum.  As explained above, the jus ad bellum regime requires that the acts of non-State actors must necessarily be attributable to the territorial State for the purposes of self-defence. At most, the territorial State’s inability may constitute a violation of the duty of due diligence but that cannot justify the use of force by the victim State.

Moreover, a State is never really unable to act as, in addition to take itself military action, it could always ask for military assistance and consent to other States intervening on its territory. And Syria not only stated that it was open to cooperate with the other States in carrying out strikes against ISIL, but later it also directly asked for Russia’s help.

However, according to part of the doctrine, if the territorial State is still unable to comply to its obligation not to allow its territory to be used to the detriment of other States, the use of force by the victim State may still be justified by invoking the institute of negotiorum gestio or the state of necessity (for a more in-depth analysis on these doctrinal alternatives see: Tancredi in ZaöRV, vol. 77, 2017, p. 60 ss.).

In the end, it must be taken into account, that according to another part of the doctrine (Corten, “The Military Operations Against the ‘Islamic State’ (ISIL or Da’esh)—2014”, in Ruys et al., p. 873 ss.; Urs, “Effective Territorial Control by Non-State Armed Groups and the Right of Self-Defence”, in ZaöRV, vol. 77, 2017, p. 28 ss.), Germany’s position on Syria’s lack of effective control would go even further than the unwilling or unable standard. According to these authors, in fact, the unwilling or unable doctrine would still base a military operation on the territory of another State on some form of responsibility (that is for the territorial State’s failure to prevent the terrorist activities). On the other hand, the lack of effective control would justify the military intervention only because the territorial State exercises, at best, limited sovereignty over its territory and it could, thus, lead to the risky effect of granting some degree of international personality to a terrorist group.

In conclusion, the judgment of the Federal Constitutional Court tried to broaden the interpretation of Article 51 although in a much more limited manner than the unwilling or unable doctrine, affirming that the right of self-defence could be exercised against non-State actors only if those have a consolidated territorial basis, as it was the case of ISIL from 2014 to March 2019.

It is important, however, to note that the Court made no mention whatsoever of the fact that ISIL lost its territorial control on the area on March 2019, no less than seven months before the end of Germany’s mandate at the time.

This situation would seem irreconcilable with the position expressed by the Court and it would also put in perspective the reasoning used by the Federal Government to justify the extension of the military operation (cited at the beginning of the post).

Indeed, even assuming that the right of self-defence could be exercised against non-State actors that have a territorial consolidated basis, the situation should necessarily be considered differently when that control is lost.

It would be, therefore, very interesting to see whether the Federal Constitutional Court could today justify the Bundestag’s subsequent decisions that extended the military operation until 31 January 2022 in the same manner.