Armed Conflict Foreign Relations & International Law

Which States Support the 'Unwilling and Unable' Test?

Elena Chachko, Ashley Deeks
Monday, October 10, 2016, 1:55 PM

As readers of Lawfare know, a growing number of States believe that use of force in self-defense against a non-state actor on the territory of a third State, without the consent of that third State, may be lawful under international law if the non-state actor has undertaken an armed attack against the State and the third State is itself unwilling or unable to address the threat posed by the non-state actor.

Published by The Lawfare Institute
in Cooperation With
Brookings

As readers of Lawfare know, a growing number of States believe that use of force in self-defense against a non-state actor on the territory of a third State, without the consent of that third State, may be lawful under international law if the non-state actor has undertaken an armed attack against the State and the third State is itself unwilling or unable to address the threat posed by the non-state actor. The content of the “unwilling or unable” test, its pedigree, and whether it has become a part of customary international law have been widely debated among international law scholars and practitioners, and one of us has addressed those issues extensively elsewhere.


One side effect of ongoing international operations against ISIL in Iraq and Syria, and of recent counterterrorism operations in other countries, is that a significant number of States have recently articulated or clarified their views about the “unwilling or unable” test. This makes it a good time to document international support for the test. In what follows, we provide an up-to-date list of the States that have expressed support for the “unwilling or unable” test (explicitly or implicitly), with the aim of making as much information as possible available in one place. We do not engage with the normative questions related to the “unwilling or unable” test. We simply hope to create a “live” resource of episodes and statements about the “unwilling or unable” test that we believe will contribute to future discussion about it. We will update and expand the post from time to time, and we welcome any comments or suggestions for information that we may have neglected to include.


Below is a list of States that have used force against non-state actors on the territory of third States without the latter’s consent. The incidents surveyed date back to the signing of the UN Charter in 1945. We have divided those States into three categories based on the legal justifications they provided (or failed to provide) for their resort to force. Category I, explicit endorsement, includes States that have specifically invoked the “unwilling or unable” language in their legal justifications for use of force. Category II, implicit endorsement, includes States that have relied on substantively similar justifications but stopped short of explicitly invoking the “unwilling or unable” test. Category III, ambiguous cases, includes States that have used force against non-state actors in third countries without clearly expressing their views on the legality of their actions under international law, and States that provided legal justifications but did not invoke the “unwilling or unable” test or a similar concept in their justifications. The entry for each State includes a list of incidents and links to relevant documents. We have also included statements from a number of States that have addressed the unwilling/unable test without recourse to any specific incident.


Some States have not been consistent in their positions, invoking the “unwilling or unable” test in their own defense in one incident only to criticize other States for relying on it in others. We classified each State based on how close it got to embracing the test at any one point in time. In other words, if a State clearly invoked the “unwilling or unable” test in at least one incident, we have listed that State in Category I, even if the State did not invoke the test in other comparable situations.


Finally, in assessing international practice with regard to developing legal norms, it is important to consider objectors. To be sure, in many of the cases cited below, the Security Council, international organizations, or other States condemned the acting State for resorting to force. While we focus in this post on the positive aspects of State practice with regard to “unwilling or unable,” we also searched for examples of States that had explicitly rejected the test by, for instance, requiring consent as a precondition for any use of force on the territory of a third State that was not sanctioned by the Security Council. Those examples are listed under a separate category, excluding the cases in which States have criticized others for relying on “unwilling or unable” after having resorted to force in similar legal circumstances in other cases. The latter type of objections would appear in the entry for the relevant State.



Category I: Explicit Endorsement


1. United States


2. United Kingdom


3. Germany


4. The Netherlands


5. Czech Republic


6. Canada


7. Australia


8. Russia


9. Turkey


10. Israel



Category II: Implicit Endorsement


1. Belgium


2. Iran


3. South Africa



Category III: Ambiguous Cases


1. France


2. Denmark


3. Norway


4. Portugal


5. Members of the GCC, Egypt, Iraq, Jordan and Lebanon


6. Colombia


7. Uganda


8. Rwanda


9. Ethiopia


10. India



Objectors


1. Syria


2. Venezuela


3. Ecuador


4. Cuba


5. Brazil


6. Mexico



Category I: Explicit Endorsement


1. United States


Territorial State(s): Syria


Non-state Actor: ISIL, Khorasan Group


Year(s): 2014 –


Official statements:


  • State Department Legal Adviser Brian Egan’s speech at ASIL, April 1, 2016: International Law, Legal Diplomacy and the Counter-ISIL Campaign (Douglas Cantwell analyzes here):

[I]n the case of ISIL in Syria, as indicated in our Article 51 letter, we could act in self-defense without Syrian consent because we had determined that the Syrian regime was unable or unwilling to prevent the use of its territory for armed attacks by ISIL…


With respect to the “unable” prong of the standard, inability perhaps can be demonstrated most plainly, for example, where a State has lost or abandoned effective control over the portion of its territory from which the non-State actor is operating. This is the case with respect to the situation in Syria. By September 2014, the Syrian government had lost effective control of much of eastern and northeastern Syria, with much of that territory under ISIL’s control.


  • U.S. Article 51 letter, September 23, 2014:

States must be able to defend themselves, in accordance with the inherent right of individual and collective self-defence, as reflected in Article 51 of the Charter of the United Nations, when, as is the case here, the government of the State where the threat is located is unwilling or unable to prevent the use of its territory for such attacks. The Syrian regime has shown that it cannot and will not confront these safe havens effectively itself. Accordingly, the United States has initiated necessary and proportionate military actions in Syria in order to eliminate the ongoing ISIL threat to Iraq... In addition, the United States has initiated military actions in Syria against al-Qaida elements in Syria known as the Khorasan Group to address terrorist threats that they pose to the United States and our partners and allies.



Territorial State: Pakistan


Non-state Actor: Al-Qaeda (the Bin-Laden operation)


Year(s): 2011


Official statements:


  • Harold Koh’s Opinio Juris post, May 19, 2011, explaining that the bin-Laden operation was carried out in accordance with the principles outlined in Koh’s 2010 speech at ASIL (see below). Among those principles is the unwilling or unable test. See further analysis of this incident by Lederman and Deeks.

Territorial State(s): Afghanistan (and others)


Non-State Actor: Al-Qaeda


Year(s): 2001 –


Official statements:


  • Former State Department Legal Adviser John Bellinger’s Opinio Juris posts, January 2007:

Over a century of state practice supports the conclusion that a state may respond with military force in self defense to attacks by a non-state actor from outside the state’s territory, at least where the harboring state is unwilling or unable to take action to quell the attacks. This includes the famous 1837 case of the Caroline, in which British forces in Canada entered the United States and set fire to a vessel that had been used by private American citizens to provide support to Canadian rebels, killing two Americans in the process.


[Referring back to the Caroline case in the third post of the series:]


… there was no question that the acts of private actors could trigger the right of self-defense where the host government was unable or unwilling to deal with the situation. Secretary Webster may not have accepted that the facts were right to legally justify the use of force in the Caroline case, but the British and Americans both accepted the underlying principle.


  • John Bellinger’s speech at the London School of Economics, October 31, 2006 (explaining the legal basis for the war against al-Qaeda in Afghanistan):

We were justified in using military force in self-defense against the Taliban because it had allowed al Qaida to use Afghanistan as an area from which to plot attacks and train in the use of weapons and it was unwilling to prevent al Qaida from continuing to do so... We gave the Taliban an opportunity to surrender those it was harboring, and when it refused, we took military action against its members. […]


Over a century of state practice supports the conclusion that a state may respond with military force in selfdefense to such attacks, at least where the harboring state is unwilling or unable to take action to quell the attacks. […]


[A]s a legal matter, where a state is unwilling or unable to do so, it may be lawful for the targeted state to use military force in self-defense to address that threat.


To those who might disagree, I would ask you to consider the alternatives. If terrorists intent on harming civilians are being harbored by a state that is unable or unwilling to act against them, what choices does the state whose civilians are in jeopardy have? If we determine the location from which Bin Laden has been planning attacks against the U.S., and the state in which he is operating is unable or unwilling to act against him, what would you have the United States do?


Territorial State(s): Afghanistan, Sudan


Non-State Actor: Al-Qaeda


Year(s): 1998


Official statements:


  • President Clinton’s Address to the Nation on Military Action Against Terrorist Sites in Afghanistan and Sudan (following the U.S. embassies bombings in Nairobi and Dar Es Salaam), August 20, 1998:

Afghanistan and Sudan have been warned for years to stop harboring and supporting these terrorist groups. But countries that persistently host terrorists have no right to be safe havens.


  • U.S Article 51 letter, August 20, 1998:

These attacks were carried out only after repeated efforts to convince the Government of the Sudan and the Taliban regime in Afghanistan to shut these terrorist activities down and to cease their cooperation with the Bin Ladin organization.


Territorial State(s): Iran


Non-State Actor: Muslim Student Followers of the Imam's Line (U.S. hostage rescue attempt)


Year(s): 1979


Official statements:


  • President Carter’s letter to the Speaker of the House and the President Pro Tempore of the Senate Reporting on the Operation, April 26, 1980:

This operation was ordered and conducted pursuant to the President's powers under the Constitution as Chief Executive and as Commander-in-Chief of the United States Armed Forces, expressly recognized in Section 8(d)(1) of the War Powers Resolution. In carrying out this operation, the United States was acting wholly within its right, in accordance with Article 51 of the United Nations Charter, to protect and rescue its citizens where the government of the territory in which they are located is unable or unwilling to protect them.



Territorial State(s): Cambodia


Non-state Actor: Viet Cong


Year(s): 1970


Official statements:


  • Former State Department Legal Adviser John Stevenson’s statement to the NYC Bar Association, Legal Aspects of U.S. Military Action in Cambodia, May 28, 1970 (pp. 5-6):

The United States Department of the Army Field Manual relating to the law of land warfare states the following rule: "Should the neutral state be unable, or fail for any reason, to prevent violations of its neutrality by the troops of one belligerent entering or passing through its territory, the other belligerents may be justified in attacking the enemy forces on this territory…


[Summarizes historical precedents to show that “the need to provide a lawful and effective remedy to a belligerent harmed by its enemy's violations of a neutral's rights” is generally recognized.] I would not suggest that those incidents and statements by themselves provide an adequate basis for analysis of the present state of the law. We all recognize that, whatever the merits of these views prior to 1945, the adoption of the United Nations Charter changed the situation by imposing new and important limitations on the use of armed force. However, they are surely authority for the proposition that, assuming the Charter's standards are met, a belligerent may take action on a neutral's territory to prevent violation by another belligerent of the neutral's neutrality which the neutral cannot or will not prevent, providing such action is required in self-defense.


  • U.S. Article 51 letter, May 5, 1970:

The measures of collective self-defence being taken by United States and South Viet-Namese forces are restricted in extent, purpose and time. They are confined to the border areas over which the Cambodian Government has ceased to exercise any effective control and which has been completely occupied by North Viet-Namese and Viet Cong forces.


Additional Government Statements:


  • Former State Department Legal Adviser Abraham Sofaer’s 1989 article, Terrorism, The Law, and The National Defense (discussing the 1985 bombing by Israel of PLO headquarters in Tunisia, p. 108):

The United States in fact supported the legality of a nation attacking a terrorist base from which attacks on its citizens are being launched, if the host country either is unwilling or unable to stop the terrorists from using its territory for that purpose.


  • Briefing by then-State Department Spokesman Nicholas Burns, responding to a question on Turkey’s use of force against the PKK in Iraq, July 7, 1995:

As we previously indicated when there was a similar operation in March, a country under the United Nations charter has the right in principle to use force to protect itself from attacks from a neighboring country if that neighboring state is unwilling or unable to prevent the use of its territory for such attacks. That is a legal definition that gives a country under the U.N. Charter the right to use force in this type of instance.


That is certainly the case with northern Iraq… . [W]hile we recognize Iraqi sovereignty throughout this area, we don't believe that the Iraqi Government has shown the responsibility to be able to assure the welfare of the people of northern Iraq; therefore there is no governing entity that has been able to prevent these attacks from the PKK. It has been up to Turkey to protect itself from them.


  • Harold Koh’s speech at ASIL, March 25, 2010:

As recent events have shown, al-Qaeda has not abandoned its intent to attack the United States, and indeed continues to attack us. Thus, in this ongoing armed conflict, the United States has the authority under international law, and the responsibility to its citizens, to use force, including lethal force, to defend itself, including by targeting persons such as high-level al-Qaeda leaders who are planning attacks… [W[hether a particular individual will be targeted in a particular location will depend upon considerations specific to each case, including those related to the imminence of the threat, the sovereignty of the other states involved, and the willingness and ability of those states to suppress the threat the target poses.


  • Fact Sheet: U.S. Policy Standards and Procedures for the Use of Force in Counterterrorism Operations Outside the United States and Areas of Active Hostilities, May 23, 2013:

[T]he following criteria must be met before lethal action may be taken….


3. An assessment that the relevant governmental authorities in the country where action is contemplated cannot or will not effectively address the threat to U.S. persons;



2. United Kingdom


Territorial State(s): Syria


Non-state Actor: ISIL


Year(s): 2014 –


Official statements:


  • Former U.K. Prime Minister David Cameron’s statement before Parliament, November 26, 2015:

[T]he main basis of the Global Coalition’s actions against ISIL in Syria is the collective self-defence of Iraq. Iraq has a legitimate government, one that we support and help. There is a solid basis of evidence on which to conclude, firstly, that there is a direct link between the presence and activities of ISIL in Syria, and their ongoing attack in Iraq...


.... and, secondly, that the Assad regime is unwilling and/or unable to take action necessary to prevent ISIL’s continuing attack on Iraq – or indeed attacks on us.


  • Prime Minister’s response to the Foreign Affairs Select Committee’s Second Report of Session 2015-16: The Extension of Offensive British Military Operations to Syria, November 2015:

The UK is already supporting the Coalition’s efforts to degrade ISIL in Syria as a necessary aspect of effectively bringing an end to ISIL’s armed attack on Iraq. On 21 October 2014, the Defence Secretary announced to Parliament that he was authorising flights of manned and unmanned surveillance aircraft over Syria to gather intelligence against ISIL. There is a solid basis of evidence on which to conclude, firstly, that there is a direct link between the presence and activities of ISIL in Syria and their ongoing attack on Iraq and, secondly, that the Assad regime is unwilling and/or unable to take action necessary to prevent ISIL’s continuing attack on Iraq.


  • U.K. Article 51 letters (no express mention of the “unwilling or unable” test):
    • Letter dated November 26, 2014
    • Letter dated September 8, 2015 (following the targeted killing by the U.K. of ISIL operatives in Syria. The letter states that this use of force was “a necessary and proportionate exercise of the individual right of self-defense of the United Kingdom”).
    • Letter dated December 3, 2015


3. Germany


Territorial State(s): Syria


Non-state Actor: ISIL


Year(s): 2015 –


Official statements:


  • Germany’s Article 51 letter, December 10, 2015:

ISIL has occupied a certain part of Syrian territory over which the Government of the Syrian Arab Republic does not at this 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. Exercising the right of collective self-defence, Germany will now support the military measures of those States that have been subjected to attacks by ISIL.


  • Application of the German Federal Government to the Bundestag, seeking approval for the government’s proposal to deploy German armed forces to prevent and suppress terrorist acts by the terrorist organization ISIL, December 1, 2015 (unofficial translation):

Beginning in September 2014, several states, which are allies to or otherwise partnered with Germany (USA, Australia, UK, France), have – upon Iraq’s request and in exercise of the right to collective self-defense within the meaning of Art. 51 of the UN Charter – opted to give military assistance to Iraq in order to exercise the latter’s right to self-defence in response to military attacks that ISIL launched from Syrian territory onto Iraqi territory. In connection with this, military actions on Syrian territory are carried out because the Syrian government is not able and/or unwilling to stop the ISIL attacks that are being launched from their territory.



4. The Netherlands


Territorial State(s): Syria


Non-state Actor: ISIL


Year(s): 2015 –


Official statements:


  • Dutch government’s answers to questions presented by the Dutch Parliament’s Permanent Committee on Foreign Affairs (answer to question 75), July 1, 2015 (unofficial translation):

The existence of a mandate in conformity with international law to act against a non-state entity in the territory of a third country requires that (1) there is an armed attack by that group; (2) the territory of that third State is used to carry out this attack; and (3) the third State is unable or unwilling to put an end to the activities of non-state entities in its territory.


  • See also letter from the Dutch Foreign Minister to Parliament, conveying the legal advice of an external international law advisor regarding use of force against ISIS in Syria, June 26, 2015 (as translated by Ruys and others, p. 282):

According to the cabinet, it is sufficiently established that there is an international legal basis for the recourse to force against ISIS in Syria. This legal basis consists in the right of collective self-defence, as enshrined in Article 51 UN Charter, in defence of Iraq against armed attacks by ISIS from Syria against Iraq.


Contrary to what was the case in September 2014, it is now sufficiently established in fact that there are continuous armed attacks from Syria against Iraq, directed by ISIS headquarters in Raqqah, Syria. In addition, fighters and weapons are continuously sent from Syria to Iraq to be deployed in the armed conflict in Iraq. It is also evident that the Syrian authorities are incapable of stopping these armed attacks. Action against ISIS in Syria is undertaken pursuant to a request from Iraq (collective exercise of the right of self-defence).


  • But see Official responses of the Dutch Ministry of Foreign Affairs to a questionnaire disseminated in the framework of this study by Jessica Dorsey and Christophe Paulussen, April 2015 (p. 32):

Under specific circumstances it is possible that force is used in self-defence against autonomous non-state actors. This does not require attribution to a third state but a determining factor in such cases is whether or not a state is willing and/or able to respond to attacks by NSA[s] [i.e. Non- State Actors] from its territory. With respect to consent the Netherlands endorses the conclusion of the Advisory Committee on Issues of Public International Law (CAVV) that valid consent for the use of force by third states on its territory must be given by the territorial state. The CAVV provides a number of criteria for assessing whether such consent is validly given. The committee refers to the requirements laid down in the Articles on the Responsibility of States for Internationally Wrongful [A]cts and the 1969 Vienna [C]onvention on the Law of Treaties.



5. Czech Republic


Territorial State(s): Syria


Non-state Actor: ISIL


Year(s): unknown


Official statements:


  • Official response of the Czech Ministry of Defense to a questionnaire disseminated in the framework of this study by Jessica Dorsey and Christophe Paulussen, April 2015 (p. 12; brackets appear in original):

… if a territorial state is unable to act against a[n] NSA[,] such [a] state must be prepared to limit its own sovereignty in order to allow a victim state to redress the situation. If a territorial state would be unwilling[,] the consequences may differ[,] as acts of such [a] state could be interpreted as a certain degree of support to [the] NSA. It is acknowledged that state sovereignty should not serve as a protection of a State if such [a] state is unable or unwilling to exercise its sovereignty within its territory. This confirms settled jurisprudence such as Lotus case… At this point we are not sure whether [the] criterion [of] unable or unwilling represents part of the customary international law requirement of necessity.



6. Canada


Territorial State(s): Syria


Non-state Actor: ISIL


Year(s): 2015 –


Official statements:


  • Canada’s Article 51 letter, March 31, 2015:

ISIL also continues to pose a threat not only to Iraq, but also to Canada and Canadians, as well as to other countries in the region and beyond. In accordance with the inherent rights of individual and collective self-defence reflected in Article 51 of the United Nations Charter, States must be able to act in self-defence when the Government of the State where a threat is located is unwilling or unable to prevent attacks emanating from its territory.



7. Australia


Territorial State(s): Syria


Non-state Actor: ISIL


Year(s): 2015 –


Official statements:


  • Australia’s Article 51 letter, September 9, 2015:

Article 51 of the Charter of the United Nations recognizes the inherent right of States to act in individual or collective self-defence where an armed attack occurs against a Member of the United Nations. States must be able to act in self-defence when the Government of the State where the threat is located is unwilling or unable to prevent attacks originating from its territory. The Government of Syria has, by its failure to constrain attacks upon Iraqi territory originating from ISIL bases within Syria, demonstrated that it is unwilling or unable to prevent those attacks.


Additional Government Statements


  • Remarks by former Prime Minister John Howard in an interview with Indonesian TV, October 19, 2004:

JOURNALIST:


[…] And what about the comments from your administration, that Australia would be prepared to launch pre-emptive attacks on any country that it found harbouring terrorists or where terrorists were operating, does that include Indonesia?



PRIME MINISTER:


Well, I certainly wouldn't envisage that that would occur in relation to Indonesia. I was not really stating that in relation to any country and I have the very strong view that countries like Indonesia, with whom we have very close relationships, if action were needed to be taken against groups that might threaten Australia then that action would be taken by the Indonesian forces. I was simply stating a principle, that principle merely was that if you ever had, how remote the likelihood of the situation in the future where a country were unable or unwilling and the only way to protect Australia was to take action, that that action would be taken. But I imagine that's a view that many countries hold. I don'tthink Australia would be alone in holding that view but I certainly don't regard that as a statement of a last resort principle as something that should be seen as being in any way antagonistic to any of our friends in the region and, most particularly, Indonesia.


8. Russia


Territorial State(s): Georgia


Non-state Actor: Chechen rebels


Year(s): 2002


Official statements:


  • Statement of Russian Federation President Vladimir Putin, September 11, 2002:

The continued existence in separate parts of the world of territorial enclaves outside the control of national governments, which, owing to the most diverse circumstances, are unable or unwilling to counteract the terrorist threat is one of the reasons that complicate efforts to combat terrorism effectively.


One such place, where the situation is giving rise to particular alarm in the Russian Federation, is the Pankisi Gorge and other areas of contiguous territory along the line of the State border between Georgia and the Russian Federation.


  • Statement of the Russian Federation Ministry of Foreign Affairs, July 31, 2002:

It should be pointed out that the Georgian authorities, who have repeatedly assured the world community of their readiness to restore by themselves order in the Pankisi Gorge, have once again acknowledged their unwillingness to take practical measures to halt terrorism. To all appearances, they are unable and really do not wish to do that there.


(*) Note: Russia has backtracked on its support for the “unwilling or unable” test in the context of coalition operations in Syria. On September 11, 2014, a Russian Foreign Ministry Spokesman said:


[T]he US President openly stated that the US armed forces may strike IS positions in the territory of Syria without consent of its legal government. Such a step without a respective decision of the UN Security Council would be an act of aggression, a gross violation of the norms of international law. There is reason to believe that the Syrian government forces can also become the target, which will incur severe consequences in terms of further escalation of tensions.


See also the Russian ambassador to the UN’s address to the Security Council, September 19, 2014 (p.19):


In order to establish a truly broad international coalition, any action aimed at combating the threat of ISIL and groups like it must be carried out in accordance with the principles of the Charter of the United Nations and the standards of international law, based on existing anti-terrorism instruments of the United Nations, and in close cooperation with the Governments of the region. An international anti-terrorist operation should be conducted either with the consent of the sovereign Governments or sanctioned by the Security Council. We consider other options to be unlawful and detrimental to international and regional stability.



9. Turkey


Territorial State(s): Iraq


Non-state Actor: PKK, ISIL


Year(s): 2015


Official statements:


  • Statement of Turkey’s representative before the Security Council regarding the situation in Iraq, December 18, 2015 (p. 5):

If the Iraqi Government claims that it has full sovereignty over all its territory, then it is our right to expect that it will prevent the use of Iraqi soil for terrorist attacks against our own territory. However, both Daesh and the PKK continue to pose significant threats to Turkey’s safety and security from areas beyond the reach of the Iraqi Government, and it is our right to exercise self-defence.


Territorial State(s): Syria


Non-state Actor: ISIL


Year(s): 2015 –


Official statements:


  • Turkey’s Article 51 letter, July 24, 2015:

It is apparent that the regime in Syria is neither capable of nor willing to prevent these threats emanating from its territory, which clearly imperil the security of Turkey and the safety of its nationals. Individual and collective self-defence is our inherent right under international law, as reflected in Article 51 of the Charter of the United Nations.


Territorial State(s): Iraq


Non-state Actor: PKK


Year(s): 2006-2008


Official statements:


  • No clear official statement by Turkey of the legal basis for use of force against the PKK in this period. But see Hakimi (p. 13), Ruys (p. 345), Van Steenberghe (p. 187), and Gray (p. 143), noting that those incidents reflect the “unwilling or unable” rationale.


Territorial State(s): Iraq


Non-state Actor: PKK


Year(s): 1995-1997


Official statements:


  • Letter from the Turkish Foreign Minister to the UN Secretary General and the Security Council, July 2, 1996:

[T]he Declaration on Principles of International Law concerning Friendly Relations and Cooperation among States in accordance with the Charter of the United Nations… stipulates that every State has the duty to refrain from, inter alia, acquiescing in organized activities within its territory directed towards the commission of terrorist acts in another State. As of this very principle, it becomes inevitable for a country to resort to necessary and appropriate force to protect itself from attacks from a neighbouring country, if the neighbouring State is unwilling or unable to prevent the use of its territory for such attacks.


  • Turkey’s Article 51 letter to the Security Council, July 24, 1995:

As Iraq has not been able to exercise its authority over the northern part of its country since 1991 for reasons well known, Turkey cannot ask the Government of Iraq to fulfil its obligation, under international law, to prevent the use of its territory for the staging of terrorist acts against Turkey. Under these circumstances, Turkey’s resorting to legitimate measures which are imperative to its own security cannot be regarded as a violation of Iraq’s sovereignty. No country could be expected to stand idle when its own territorial integrity is incessantly threatened by blatant cross-border attacks of a terrorist organization based and operating from a neighbouring country, if that country is unable to put an end to such attacks.


  • Also see letter from the Turkish Foreign Minister to the UN Secretary General and the President of the Security Council, July 14, 1997.


10. Israel


Territorial State(s): Lebanon


Non-state Actor: Hezbollah


Year(s): 2006


Official statements:


  • Israel’s Article 51 letter, July 12, 2006 (see also former Israeli Ambassador to the UN Dan Gillerman’s speech, p. 5):

Responsibility for this belligerent act of war lies with the Government of Lebanon, from whose territory these acts have been launched into Israel… The ineptitude and inaction of the Government of Lebanon has led to a situation in which it has not exercised jurisdiction over its own territory for many years


Israel thus reserves the right to act in accordance with Article 51 of the Charter of the United Nations and exercise its right of self-defence when an armed attack is launched against a Member of the United Nations.


Territorial State(s): Lebanon


Non-state Actor: Hezbollah


Year(s): 1996


Official statements:


  • Israeli Ambassador to the UN Gad Yaacobi’s address to the Security Council, April 15, 1996 (p. 6):

Israel’s primary obligation is to protect the security of all of its citizens. We will not allow our civilian population centres to be held hostage by Hezbollah. The Lebanese Government does not have the ability — or the will — to control Hezbollah activities. Therefore, Israel must defend the security of its north by all necessary measures.


Territorial State(s): Lebanon


Non-state Actor: Hezbollah, Popular Front for the Liberation of Palestine and others


Year(s): 1993


Official statements:


  • Israel’s letter to the Security Council (invoking the right of self defense in general terms), July 26, 1993.


Territorial State(s): Tunisia


Non-state Actor: Palestinian Liberation Organization (PLO)


Year(s): 1985


Official statements:


  • Then-Israeli Ambassador to the UN Benjamin Netanyahu’s address to the Security Council, October 2, 1985 (paras. 65-69):

Indeed, scores of Member States, many of them in this chamber today, have often claimed precisely this right to act in self-defence to curb armed attacks from other countries. The only question that may arise is whether other remedies are available. In this case none existed. On the contrary, Tunisia did not show an inkling of a desire or an intention to prevent the PLO from planning and initiating terrorist activities from its soil.


Territorial State(s): Lebanon


Non-state Actor: PLO


Year(s): 1978-1982


Official statements:


  • Former Israeli Ambassador to the UN Haim Herzog’s address to the Security Council, March 17, 1978 (paras. 53-54):

53. What Israel did is what any self-respecting sovereign State would do in the circumstances. What Israel did is fully in accordance with the norms of international law and the Charter of the United Nations. International law is quite clear on this subject… the subject is clearly dealt with by Fawcett:


“where incursion of armed bands is a precursor to an armed attack, or itself constitutes an attack, and the authorities in the territory, from which the armed bands came, are either unable or unwilling to control and restrain them, then armed intervention, having as its sole object the removal or destruction of their bases, would – it is believed – be justifiable under Article 51”.


54. I do not wish to presume upon the time of the Council by going into a lengthy legal discussion on the issue except to say that the aforementioned legal passages reflect international law on the subject and support Israel’s legal position.


  • UN Yearbook 1979 (p. 332):

Israel said it was exercising its inherent right of self-defence. If States were unwilling or unable to prevent terrorists from operating out of their countries, they should be prepared for reprisals.


  • Former Israeli Ambassador to the UN Yehuda Blum’s address to the Security Council, July 17, 1981 (paras. 54-55):

54. Members of the Council need scarcely be reminded that under international law, if a State is unwilling or unable to prevent the use of its territory to attack another State, that latter State is entitled to take all necessary measures in its own defence.


55. The Government of Israel is in fact exercising the inherent right of self-defence enjoyed by every sovereign State, a right also preserved under Article 51 of the Charter of the United Nations. Israel’s response to PLO terror is what any self-respecting sovereign State would do in similar circumstances.


  • Israel’s letter to the UN Secretary General, May 28, 1982:

…Lebanon’s duty to prevent its territory from becoming used for terrorist attacks against other States is based on general international law. [Quoting Oppenheim and Lauterpacht] “States are under a duty to prevent and suppress such subversive activity against foreign Governments as assumes the form of armed hostile expeditions…”


  • See also former Israeli Ambassador to the UN Yehuda Blum’s address to the Security Council, June 6, 1982, here, in particular para. 54.

(*) Note: A few recent incidents exist involving use of force by Israel against non-state actors in third States, for which no legal justification has been provided: Israel’s alleged attacks against Hezbollah in Syria in, e.g., 2013, 2014, 2015, and 2016, and several reported attacks in Sudan intended to curb the flow of weapons to Hamas in Gaza (2009, 2011, 2012, 2015).


(*) Note: we only cite the major military operations Israel has conducted against non-state actors in third States. For a comprehensive overview of additional incidents involving Israel, see Wettberg, pp. 230-239.



Category II: Implicit Endorsement



1. Belgium


Territorial State(s): Syria


Non-state Actor: ISIL


Year(s): 2016 –


Official statements:


  • Belgium’s Article 51 letter, June 9, 2016:

ISIL has occupied a certain part of Syrian territory over which the Government of the Syrian Arab Republic does not, at this time, exercise effective control. In the light of this exceptional situation, States that have been subjected to armed attack by ISIL originating in that part of the Syrian territory are therefore justified under Article 51 of the Charter to take necessary measures of self-defence. Exercising the right of collective self-defence, Belgium will support the military measures of those States that have been subjected to attacks by ISIL. Those measures are directed against the so-called “Islamic State in Iraq and the Levant” and not against the Syrian Arab Republic.



2. Iran


Territorial State(s): Iraq


Non-state Actor: Mujahedeen-e-Khalq (MKO/MEK)


Year(s): 2000-2001


Official statements:


  • Iran’s Article 51 letter, April 19, 2001:

…the Islamic Republic of Iran expects the Government of Iraq to take appropriate measures in conformity with the rules and principles of international law as well as its obligations under the relevant Security Council resolutions… to put an end to the use of its territory for cross-border attacks and terrorist operations against the Islamic Republic of Iran, which would render unnecessary measures in self-defence in accordance with Article 51 of the Charter of the United Nations.


  • Annex to Iran’s letter to the UN Secretary General, enclosing a letter from the Iranian Foreign Ministry to the Iraqi embassy in Tehran, March 26, 2001:

The Government of the Islamic Republic of Iran… holds the Government of the Republic of Iraq responsible for the adverse consequences of [acts of hostility] resulting from the provision of sanctuary to the terrorists of MKO on Iraqi soil and the creation of favourable conditions for them to organize armed acts of terrorism and sabotage against the Islamic Republic of Iran, which are in flagrant contravention of international norms and principles and the United Nations Charter, as well as the principles of good- neighbourly relations.



Territorial State(s): Iraq


Non-state Actor: Mujahedeen-e-Khalq (MKO/MEK)


Year(s): 1999


Official statements:


  • Iran’s Article 51 letter, July 12, 1999:

The Government of Iraq, by providing sanctuary and unhesitating support to this terrorist organization, violates its obligations under the basic principles of international law and disregards the continuous call by the United Nations to further strengthen cooperation between States in order to prevent, combat and eliminate terrorism in all its forms and manifestations…


… in the exercise of its right of self-defence under Article 51 of the Charter, the concerned authorities of the Islamic Republic of Iran targeted a well-known active terrorist camp, located in the territory of Iraq, on 10 June 1999. This proportionate action was a necessary defensive measure against the perpetrators of the terrorist crimes that had already been carried out against Iran and its citizens. It also aimed to prevent further recurrence of similar terrorist operations… As stated in the past, Iran holds the Iraqi regime fully responsible for the consequences of any terrorist acts and operations which are planned and nurtured in Iraq and directed against Iranian citizens and territory…


Territorial State(s): Iraq


Non-state Actor: Mujahedeen-e-Khalq (MKO/MEK)


Year(s): 1996


Official statements:


  • Iran’s Article 51 letter, July 29, 1996:

As you are aware, owing to prevailing circumstances, the Government of Iraq is not in a position to exercise effective control over its territory in the northern part of that country. Consequently, in recent weeks transborder armed attacks and sabotage operations by terrorist groups against Iranian border towns, originating from Iraqi territory, have been intensified and escalated…


In response to these encroachments by terrorist armed groups and in accordance with its inherent right of self-defence enshrined in Article 51 of the Charter, the Islamic Republic of Iran took immediate and proportional measures, which were necessary for curbing and suppressing such aggressive activities.


(*) Note: Iran’s legal justifications for the next two incidents are ambiguous as to the extent to which Iran was attributing MEK’s actions to Iraq. It is therefore difficult to tell whether Iran advanced a state responsibility argument or an “unwilling or unable” argument.



Territorial State(s): Iraq


Non-state Actor: Mujahedeen-e-Khalq (MKO/MEK)


Year(s): 1994


Official statements:


  • Iran’s Article 51 letter, November 10, 1994:

The Islamic Republic of Iran has, on numerous occasions, notified the Government of Iraq of its serious concern about and the unacceptability of transborder armed attacks and sabotage operations by terrorist groups against Iranian border towns that originate from the territory of Iraq and constitute a grave violation of sovereignty and territorial integrity of the Islamic Republic of Iran. The Government of the Islamic Republic of Iran has consistently objected to the Government of Iraq for the presence in its territory of terrorist groups enjoying its military, financial, logistical and intelligence supports…


In response to these transborder armed attacks and in accordance with its inherent right of self-defence enshrined in Article 51 of the Charter of the United Nations, the Islamic Republic of Iran took two proportional and necessary steps…


Territorial State(s): Iraq


Non-state Actor: Mujahedeen-e-Khalq (MKO/MEK)


Year(s): 1993


Official statements:


  • Iran’s Article 51 letter, May 26, 1993:

Notwithstanding the fact that the Islamic Republic of Iran has, on numerous occasions, warned the Government of Iraq against the use of its territory for launching armed attacks on and incursions into Iran, today’s air raid against the terrorists’ military bases in Iraq, a purely defensive measure in the exercise of its inherent right to self-defence, is without prejudice to Iran’s policy of respecting the sovereignty and territorial integrity of Iraq…


(*) Note: Iran has also used force against the PJAK on Iraqi territory several times, including in 2007 (here and here), 2009 and 2011. However, the Security Council records for those years (2007, 2009, 2011) indicate that Tehran did not notify the Council of the attacks or articulate the legal basis for them.


(*) Note: Similarly to Russia, Iran has recently objected to U.S. use of force against ISIL in Syria. Iranian President Hassan Rouhani has said that use of force in Syria absent a UN mandate or the consent of the affected State is illegal (quoted here, September 23, 2014).




3. South Africa


Territorial State(s): Botswana


Non-state Actor: African National Congress (ANC)


Year(s): 1985-1988


Official statements:


  • Statement by the South African representative to the Security Council, June 14, 1985 (UN yearbook 1985, p. 189):

In a statement of 14 June, South Africa provided its version of the events. It said it had repeatedly warned Botswana to curtail the activities of ANC members inside Botswana and in particular their planning and execution of terrorist activities in South Africa, and had provided Botswana with information on such activities. South Africa had no alternative but to protect itself from the increasing terrorist attacks emanating from Botswana.


  • See also UN yearbook 1988, pp. 160-161.


Territorial State(s): Lesotho


Non-state Actor: African National Congress (ANC)


Year(s): 1982, 1985


Official statements:


  • The South African representative’s address to the Security Council, December 30, 1985:

I have been instructed by my Government to object in the
strongest possible terms to the charges of “unprovoked armed aggression against 
Lesotho by South Africa”…


It needs to be recorded that South Africa has on numerous occasions in the past sought to solicit Lesotho’s co-operation to address mutual security problems. Lesotho has, however, consistently been unwilling, for obvious reasons, to commit itself to co-operation in this regard…


South Africa has experienced terrorist violence emanating from Lesotho’s territory, where the ANC is given sanctuary… The fact is that Lesotho welcomes and harbours these persons – people who plan violence and kill indiscriminately in South Africa.


  • See also UN Yearbook 1985, pp. 193-196.


Territorial State(s): Angola


Non-state Actor: South West Africa People’s Organization (SWAPO)


Year(s): 1978-1984


Official statements:


  • Letter from the South African Minister of Foreign Affairs to the UN Secretary General, August 27, 1981:

The growing commitment of certain Governments in Africa to the philosophy of violence and officially sanctioned acts of subversion is not limited to the southern part of Africa or for that matter to Africa. It is a global threat. By providing sanctuary to the perpetrators of terrorism these Governments are just as guilty as if they were accessories... Not much time is left for the responsible leaders of southern Africa in particular to reflect on the consequences of the impending cycle of conflict which confronts them. Unless they take a resolute stand against allowing their territories to serve as launching sites for aggression against a neighbouring state, the entire sub-continent is headed for a turbulent era with potentially catastrophic dimensions.


Territorial State(s): Mozambique


Non-state Actor: African National Congress (ANC)


Year(s): 1980-1981


Official statements:


  • Letter from the South African Minister of Foreign affairs to the UN Secretary General, February 6, 1981:

The Mozambique Government was warned on several occasions that unless practical steps were taken to put an end to [ANC] activities South Africa would be forced to act and take appropriate steps.


[…]


I am constrained to reaffirm the South African Government’s position on terrorism, namely that it is resolutely committed to act against the threat which terrorism poses to South Africa and its people, whether it originates within South Africa or in a neighboring country. A country actively or passively supporting those who plan and commit terrorism and subversion, and which, in addition, harbours them, will have to bear the consequences.


  • See also Note from the Department of Foreign Affairs of South Africa addressed to the Ministry of Foreign Affairs of Mozambique, February 19, 1980 (in annex II).


Territorial State(s): Zambia


Non-state Actor: SWAPO


Year(s): 1979-1980


Official statements:


  • Letter from the Minister of Foreign Affairs of South Africa to the Security Council, April 10, 1980:

As has been pointed out to the Secretary-General in numerous communications, a situation of instability exists in the border area between South West Africa/ Namibia on the one hand and Zambia and Angola on the other hand, because of the presence of armed SWAPO terrorists who are allowed to attack South West Africa/ Namibia from bases in Angola and Zambia…


South Africa remains responsible for the peace and security of South West Africa/Namibia and its inhabitants. It, therefore, has no alternative but to take protective action against aggression committed from Zambian soil. South Africa's actions are in direct response to the threat posed by these terrorist activities. They are aimed solely at the elements committing aggression and not against the countries concerned or their citizens. Zambia must bear full responsibility for allowing terrorist elements to establish sanctuaries in and operate from, its territory.


  • See also South Africa’s letter to the Security Council, September 17, 1979.

(*) Note: South Africa has criticized Turkey’s incursions into Iraq in the NAM framework. See the South African ambassador to the UN’s letter to the UN Secretary General, transmitting the final document of the 2000 NAM Ministerial Conference, June 6, 2000 (para. 137):


We strongly condemn the repeated actions of Turkish armed forces violating the territorial integrity of Iraq under the pretext of fighting guerilla elements hiding inside Iraqi territory. These actions of Turkish armed forces constitute stark illegal violations of the international boundaries mutually recognised between the two countries… We also reject the so-called “hot-pursuit” measures adopted by Turkey to justify such actions that are abhorrent to international law and to the norms of practice amongst States.



Category III: Ambiguous Cases


1. France


Territorial State(s): Syria


Non-state Actor: ISIL


Year(s): 2015 –


Official statements:


  • France’s Article 51 letter, September 9, 2015:

By resolutions 2170 (2014), 2178 (2014) and 2199 (2015) in particular, the Security Council has described the terrorist acts of [ISIL], including abuses committed against the civilian populations of the Syrian Arab Republic and Iraq, as a threat to international peace and security. Those acts are also a direct and extraordinary threat to the security of France.


In a letter dated 20 September 2014… the Iraqi authorities requested the assistance of the international community in order to counter the attacks perpetrated by ISIL.


In accordance with Article 51 of the Charter of the United Nations, France has taken actions involving the participation of military aircraft in response to attacks carried out by ISIL from the territory of the Syrian Arab Republic.



Territorial State(s): Tunisia


Non-state Actor: Algerian rebels (FLN)


Year(s): 1957-1959


Official statements:


  • Letter from the French ambassador to the UN to the President of the Security Council, February 14, 1958:

In bringing a complaint before the Security Council, it is the purpose of the French Government to make it clear that the Tunisian Government has not shown itself capable of maintaining order on the Franco-Tunisian frontier, or disposed to do so. Tunisia thus stands in violation of the obligations assumed by it under Article 4 of the Charter…


It is in these circumstances that the Algerian rebels, aided and abetted by the Tunisian authorities, have been able in recent months to establish in Tunisia a complete organization enabling them to carry out numerous border violations and incursions into French territory where they commit particularly heinous crimes…


The French Government had warned the Tunisian Government of the heavy responsibility it was assuming by lending its assistance to the rebels. It had suggested measures to prevent the recurrence of such incidents. These warnings have unfortunately been without effect and no positive response has been made to our suggestions.


  • See also UN yearbook 1958, pp. 77-79, and the French ambassador’s June 2, 1958 address to the Security Council, beginning at para. 70.


(*) Note: Since 2013, France has been using force in Mali against al-Qaeda affiliated Islamist groups. In this context, France has also attacked a convoy moving weapons to Mali on the territory of Niger. There has been some debate about the legal basis for France’s actions (see, e.g., Hakimi, pp. 11-12). The initial intervention was likely sanctioned by UNSC (but see here), and current operations appear to be conducted with the consent of the Malian government. These actions therefore do not appear to implicate the “unwilling or unable” test.



2. Denmark


Territorial State(s): Syria


Non-state Actor: ISIL


Year(s): 2016 –


Official statements:


  • Denmark’s Article 51 letter, January 13, 2016:

I am writing in accordance with Article 51 of the Charter of the United Nations to report to the Security Council that the Kingdom of Denmark, as called for by the Council in its resolution 2249 (2015) and in response to the request by the Government of Iraq, is taking necessary and proportionate measures against [ISIL] in Syria in exercise of the inherent right of collective self-defence as part of international efforts led by the United States of America.


The Security Council recognized in its resolution 2249 (2015) that ISIL constitutes a global and unprecedented threat to international peace and security. In this respect, the Council noted the letters… from the Government of Iraq stating that ISIL has established a safe haven outside Iraq’s borders that is a direct threat to the security of the Iraqi people and territory. Furthermore, the Council condemned the horrifying terrorist attacks perpetrated by ISIL including in Sousse, Ankara, Beirut and Paris and over Sinai, and noted that ISIL has the capability and intention to carry out further attacks.


The Security Council called upon Member States to prevent and suppress terrorist acts committed by ISIL and to eradicate the safe haven ISIL has established over significant parts of Iraq and Syria. In accordance with Article 51 of the Charter of the United Nations, the Kingdom of Denmark is taking measures against ISIL in support of this call.



3. Norway


Territorial State(s): Syria


Non-state Actor: ISIL


Year(s): 2016 –


Official statements:


  • Norway’s Article 51 letter, June 3, 2016:

I am writing in accordance with Article 51 of the Charter of the United Nations to report to the Security Council that the Government of Norway is taking necessary and proportionate measures against the terrorist organization [ISIL] in Syria in the exercise of the right of collective self-defence.


The Security Council recognized in its resolution 2249 (2015) that ISIL constituted a global and unprecedented threat to international peace and security and called upon Member States to prevent and suppress terrorist acts committed by ISIL and to eradicate the safe haven that ISIL had established over significant parts of Iraq and Syria... In that respect, the Council noted the letters… from the Iraqi authorities stating that ISIL had established a safe haven outside Iraqi borders in Syria that was a direct threat to the security of the Iraqi people and territory. The Government of Iraq requested the United States to lead international efforts to strike ISIL sites and military strongholds.


Pursuant to that request, the Government of Norway is taking measures against ISIL in accordance with Article 51 of the Charter of the United Nations. The measures are directed against ISIL, not against the Arab Republic of Syria.



4. Portugal


Territorial State(s): Senegal


Non-state Actor: Anti-Portuguese rebels


Year(s): 1969–1971


Official statements:


  • UN Yearbook 1969, The Portuguese representative’s address to the Security Council, December 1969 (p. 138):

Since the beginning of the year… there had been many border violations involving firing of mortars and heavy artillery from Senegal, and armed attacks in which Senegalese troops had sometimes participated. The crux of the problem… was that all such incidents resulted from armed attacks by anti-Portuguese organizations that were allowed to operate from bases inside Senegal…


Portugal had limited itself to actions strictly in conformity with the needs of its rightful duty of self-defence.


Territorial State(s): Guinea


Non-state Actor: Anti-Portuguese rebels


Year(s): 1969


Official statements:


  • UN Yearbook 1969, The Portuguese representative’s address to the Security Council, December 1969 (p. 142):

… Portugal's representative denied Guinea's allegations of shelling supposed to have taken place on 10 September and 13 November 1969, and said his Government had no evidence of any air raid; [sic] or shelling alleged to have occurred over the previous six months. He claimed that three Portuguese Guinea villages had suffered four attacks on 12 and 17 December by shelling or by armed bands from Guinea. Whatever action Portuguese forces might have taken in reply, its representative emphasized, had occurred on Portuguese territory, and had always been exclusively in self-defence, the right to which was clearly enshrined in Article 51 of the United Nations Charter.


Territorial State(s): Zambia


Non-state Actor: Anti-Portuguese rebels


Year(s): 1969


Official statements:


  • UN Yearbook 1969, The Portuguese representative’s address to the Security Council, July 1969 (p. 136):

The representative of Portugal denied the specific Zambian allegation concerning Lote village, stating that between 30 June and 3 July Portuguese security forces had been attacked by armed raiders from Zambia. Describing encounters with Zambian soldiers and armed raiders inside Portuguese territory on 21 and 23 June, he said that he could cite many more such violations of Portuguese territory.


It was not in self-defense, he said, that Zambia had authorised hostile elements to establish bases on its territory and had permitted frequent armed attacks on the adjoining Portuguese territories. Zambian armed forces, including the air force, had also been involved. Zambia must assume responsibility for attacks by elements proceeding from its territory and fleeing back for sanctuary. The Portuguese Government ensured obedience to strict instructions to its own forces to respect the territorial integrity of Zambia…


  • See also: UN yearbook 1967, pp. 131-132; UN yearbook 1968, p. 159; UN yearbook 1970, pp. 187-192 ; UN yearbook 1971, pp. 116-121 (describing additional skirmishes between Portugal and Senegal, Zambia, and Guinea).


5. Members of the GCC, Egypt, Iraq, Jordan, Lebanon


Territorial State(s): Syria


Non-state Actor: ISIL


Year(s): 2014 –


Official statements:



The participating states agreed to do their share in the comprehensive fight against ISIL, including: stopping the flow of foreign fighters through neighboring countries, countering financing of ISIL and other violent extremists, repudiating their hateful ideology, ending impunity and bringing perpetrators to justice, contributing to humanitarian relief efforts, assisting with the reconstruction and rehabilitation of communities brutalized by ISIL, supporting states that face the most acute ISIL threat, and, as appropriate, joining in the many aspects of a coordinated military campaign against ISIL.


(*) Note: The members of the GCC, Egypt, Iraq, Jordan and Lebanon are also members of the Arab League. In December 2015, the Arab League adopted resolution 7987, condemning Turkey for using force in Iraq. The resolution demands that “the Turkish Government refrain from violating Iraqi sovereignty in the future under any pretext whatsoever”. See also previous Arab condemnations of Turkish incursions into Iraq (Arab League 1996; GCC 1997).



(*) Note: On several occasions in 2014, Egypt and the UAE reportedly attacked Islamist-allied militias in Libya. Neither State publically acknowledged the strikes, and therefore provided no clear legal justifications for its actions (see here).



(*) Note: On February 16, 2015 Egypt attacked ISIS targets in Libya, in response to the beheading of 21 members of the Egyptian Coptic minority. At the Security Council session on February 18, 2015, Egypt appeared to argue that Libya had consented to use of force by Egypt on its territory (p. 7):


Egypt has decided to respond to the requests and needs of the Government of Libya and has provided military assistance. We will not hesitate to confront the terrorist threat that challenges our region with its ugliest face. This despicable organization is seeking to spread terror throughout the Arab and Islamic world — from Iraq to Syria to Libya and through them to the heart of Europe, which is the closest continent to our region and the most susceptible to the threat that this and similar organizations pose.


6. Colombia


Territorial State(s): Ecuador


Non-state Actor: Revolutionary Armed Forces of Colombia (FARC)


Year(s): 2008


Official statements:


  • Columbia did not clearly articulate the legal justification for its use of force on Ecuador’s territory, and was heavily criticized in the aftermath of the incident. For extensive discussion of the incident, see Deeks, from p. 537.


7. Uganda


Territorial State(s): Democratic Republic of the Congo (DRC)


Non-state Actor: Ugandan rebels


Year(s): 1998-1999 (the post-consent period)


Official statements:


  • The Position of the High Command on the Presence of the UPDF [Uganda People’s Defense Force] in the DRC (quoted in the ICJ’s DRC v. Uganda Judgment, 2005, at para. 109):

WHEREAS for a long time the DRC has been used by the enemies of Uganda as a base and launching pad for attacks against Uganda;


AND


WHEREAS the successive governments of the DRC have not been in effective control of all the territory of the Congo;


AND


WHEREAS in May 1997, on the basis of a mutual understanding the Government of Uganda deployed UPDF to jointly operate with the Congolese Army against Uganda enemy forces in the DRC;


[…]


NOW THEREFORE the High Command sitting in Kampala this 11th day of September, 1998, resolves to maintain forces of the UPDF in order to secure Uganda’s legitimate security interests which are the following:


1. To deny the Sudan opportunity to use the territory of the DRC to destabilize Uganda.


2. To enable UPDF [to] neutralize Uganda dissident groups which have been receiving assistance from the Government of the DRC and the Sudan.


3. To ensure that the political and administrative vacuum, and instability caused by the fighting between the rebels and the Congolese Army and its allies do not adversely affect the security of Uganda.


4. To prevent the genocidal elements, namely, the Interahamwe, and ex-FAR, which have been launching attacks on the people of Uganda from the DRC, from continuing to do so.


5. To be in position to safeguard the territory integrity of Uganda against irresponsible threats of invasion from certain forces.”



8. Rwanda


Territorial State(s): Democratic Republic of the Congo (DRC)


Non-state Actor: Hutu rebels


Year(s): 2004


Official statements:


  • Letter from the Rwandan ambassador to the UN to the Security Council, November 30, 2004:

We therefore ask once again, for how long will the Rwandan people have to live with the spectre of genocide on their doorstep? We have waited 10 years for an answer from the Security Council. We find it difficult to wait any longer.


What are the options in resolving this problem? We have repeatedly called on the Congolese authorities to deal with this situation decisively. Cognizant of stated incapacities of that country and the lack of an effective response from the international community, we have offered to work jointly with the Government of the Democratic Republic of the Congo to deal with this problem. This has been rejected. We have even been willing to place Rwandan troops under Congolese command and control to deal with the problem. This has not been accepted either. It seems to us that Rwanda is expected to simply wait and fold its arms while its people are killed, its infrastructure is destroyed and destabilization continues. This Rwanda is not willing to do.


  • Letter from the Rwandan ambassador to the UN to the President of the Security Council, April 29, 2004:

The Rwanda Government is dismayed by the continued failure of the Government of the Democratic Republic of the Congo to comprehensively address the problem of Interahamwe that are based in their territory. Over the last 10 years, Rwanda has also tried to engage successive Governments in Kinshasa in finding a solution to the problem, but instead of working with us towards solving the problem, Kinshasa Governments have actively sponsored these negative forces and, in violation of the Lusaka and Pretoria agreements and Security Council resolutions, have allowed them to operate freely in their territory and even recruited them to serve in the very ranks of the Kinshasa Governments’ armed forces.



Again in December 2004, Rwanda invoked the DRC's failure to prevent attacks by Hutu rebel groups as a ground for military operations of the Rwandese army in Eastern Congo. Rwanda did not accuse the DRC of supporting the rebels, yet argued that Congo and MONUC (the UN peacekeeping mission in the DRC) had not complied with their obligations under Resolution 1565 (2004) to disarm these groups. Therefore, Rwanda would take whatever means necessary to protect its borders, even if this meant attacking rebels inside the DRC. Rwanda did promise, however, not to attack Congolese troops.


(*) Note: In the letters cited above Rwanda consistently denied the DRC’s allegations that Rwandan forces had operated on DRC territory. The UN Organisation Mission in the Democratic Republic of Congo (MONUC), however, presented evidence to the contrary, and on December 7, 2004, the Security Council issued this press statement expressing “its very deep concern at multiple reports of military operations by the Rwandan army in the Eastern part of the Democratic Republic of the Congo and at threats by the Government of Rwanda in this regard.”



9. Ethiopia


Territorial State(s): Somalia


Non-state Actor: Islamist Forces of the Union of Islamic Courts (UIC)


Year(s): 2006


Official statements:


  • Report of the special representative of the Secretary General and head of the UN political office for Somalia to the Security Council, December 26, 2006 (quoting an Ethiopian statement, p.3):

On 23 December, leaders of the Union of Islamic Courts issued a call for jihad against the Ethiopian troops, whom they accused of invading Somalia, and appealed to foreign fighters to join that jihad. The Ethiopian Government, on 24 December, admitted the presence of its combat troops inside Somalia. In an official statement, Prime Minister Meles Zenawi declared that his country had “taken self-defensive measures and started counter-attacking the aggressive extremist forces of the Islamic Courts and foreign terrorist groups”.


  • See also this analysis of the legal basis for the Ethiopian incursion into Somalia by Christine Gray (pp. 250-251):

There is some uncertainty as to the precise legal basis for the Ethiopian action. Ethiopia generally denied the presence of its forces in Somalia until December 2006. It then claimed self-defence. This was clearly not self-defence against an armed attack by government forces, but apparently self-defence as part of the ‘war on terror’ against the threat posed by the UIC, and against its past terrorist attacks. There was no report to the Security Council under Article 51. Ethiopia did not offer any reasoned legal case in defence of its use of force in the UN. Its major military operations extending far beyond the border area look more like action to protect the TFG government [the Ethiopian-backed transitional government in Somalia] against the UIC than self-defence of Ethiopia. A stronger legal basis for intervention might have been intervention at the invitation of the legitimate (though ineffective) government supported by the UN, in response to prior foreign intervention as set out in the UN reports. The Prime Minister of the TFG after the event spoke of ‘Ethiopia’s intervention on behalf of the UN-backed TFG’. There were indications in the speech of the Prime Minister to the Ethiopian parliament on 2 January 2007 that this was an additional basis for its use of force, but it was not entirely clear how far this was being put forward as a legal argument.


10. India


Territorial State(s): Pakistan


Non-state Actor: Jaish-e-Mohammad (JeM)


Year(s): 2019


Official statements:


  • Statement by the Indian Foreign Secretary on the strike on a JeM training camp in Balakot (Feb, 26, 2019):


On 14 February 2019, a suicide terror attack was conducted by a Pak based terrorist organization Jaish-e-Mohammad., [ ] JeM has been active in Pakistan for the last two decades, and is led by MASOOD AZHAR with its headquarters in Bahawalpur.


This organization, which is proscribed by the UN, has been responsible of a series of terrorist attacks including on the Indian Parliament in December 2001 and the Pathankot airbase in January 2016.


Information regarding the location of training camps in Pakistan and PoJK [Pakistan-occupied Jammu and Kashmir] has been provided to Pakistan from time to time. Pakistan, however, denies their existence. The existence of such massive training facilities capable of training hundreds of jihadis could not have functioned without the knowledge of Pakistan authorities.


India has been repeatedly urging Pakistan to take action against the JeM to prevent jihadis from being trained and armed inside Pakistan. Pakistan has taken no concrete actions to dismantle the infrastructure of terrorism on its soil.


Credible intelligence was received that JeM was attempting another suicide terror attack in various parts of the country, and the fidayeen jihadis were being trained for this purpose. In the face of imminent danger, a preemptive strike became absolutely necessary.


[…]
The Government of India is firmly and resolutely committed to taking all necessary measures to fight the menace of terrorism. Hence this non-military preemptive action was specifically targeted at the JeM camp. The selection of the target was also conditioned by our desire to avoid civilian casualties. […]


The Government of Pakistan had made a solemn commitment in January 2004 not to allow its soil or territory under its control to be used for terrorism against India. We expect that Pakistan lives up to its public commitment and takes follow up actions to dismantle all JeM and other camps and hold the terrorists accountable for the actions.


  • For analysis of the legal implications of India’s statement, see, e.g., Henderson, O’Connell, Pillai and Burra.


Objectors


1. Syria


Territorial State(s): Syria


Non-state Actor: ISIL


Year(s): 2014 –


Official statements:


  • Syria’s letter to the UN Secretary General and the Security Council, December 29, 2015:

[A]ny attempt to invoke Article 51 of the Charter to justify military action on Syrian territory without coordination with the Syrian Government manipulates, distorts and misinterprets the provisions of that Article. The international community recognizes that the exercise of legitimate defence is subject to conditions that were put in place in order to uphold international law and the principles of sovereignty and non-interference, and to prevent the threat or use of force. Among the conditions required by Article 51 are that there should be an ongoing and effective act of aggression on the part of an armed force against a Member State, that the response should be temporary, and that it should respect the authority and responsibility of the Security Council. The military actions taken by Britain and other States in Syria do not meet those conditions. As a result, they belong outside the scope of international law, absent full cooperation and prior coordination with the Syrian State and its legitimate institutions as is the case with the Syrian and Russian Governments.


  • Syria’s letter to the UN Secretary General and the Security Council, September 21, 2015:

The United States, Britain, France, Canada and Australia have sought to justify their intervention in Syria by citing the fight against ISIL. They have invoked Article 51 of the Charter of the United Nations, but have not consulted with the Syrian Government. That course of action distorts the provisions of the Charter and manipulates international law.


2. Venezuela


Territorial State(s): Syria


Non-state Actor: ISIL


Year(s): 2014 –


Official statements:


  • The Venezuelan ambassador’s address to the Security Council, August 17, 2015 (p. 4):

We reiterate our commitment to the sovereignty, territorial integrity and political independence of the Syrian Arab Republic, in line with international law, including the Charter of the United Nations.



3. Ecuador


Territorial State(s): Syria


Non-state Actor: ISIL


Year(s): 2014 –


Official statements:


  • Statement of the foreign ministry of Ecuador regarding the U.S. Offensive on Syrian Territory, September 24, 2014 (unofficial translation):

The Government of Ecuador rejects the bombing today by the United States and other countries on Syrian territory, conceived as the beginning of an offensive designed to combat the jihadist organization "Islamic State".


Those actions were carried out in contravention of international law, as the United Nations General Assembly has not been informed and there was no Security Council authorization.


Moreover, the said offensive has been carried out without the consent of the government of Syria, which has made repeated offers to cooperate with the international community to address the threat posed by the advance of the Islamic State. Therefore, the military action this morning constitutes a violation of the sovereignty of the Syrian State and a threat to its territorial integrity…


Territorial State(s): Ecuador


Non-state Actor: Revolutionary Armed Forces of Colombia (FARC)


Year(s): 2008


Official statements:


  • Ecuador’s letter to the Security Council, March 3, 2008:

…In the framework of international law, the Ecuadorian State has always cooperated with the Colombian authorities in actions that are consistent with the two countries’ laws and with human rights. Unfortunately, such bilateral cooperation was not in evidence in relation to the [Colombian incursion], which therefore constitute[s] a violation of Ecuador’s territorial integrity and legal framework.


The Government of Ecuador is deeply disappointed by the actions of the Colombian forces. At the same time, it rejects the presence of members of irregular Colombian groups in its territory. The Government of Ecuador reiterates its strong determination not to allow the nation’s territory to be used by third parties for the conduct of military operations or as a base of operations in the context of the Colombian conflict... No military force, whether regular or irregular, may take action in Ecuadorian territory…


(*) Note: See also the declaration of the Organization of American States (OAS), March 5, 2008, condemning Colombia’s incursion into Ecuador, and stating that it “constitutes a violation of the sovereignty and territorial integrity of Ecuador and the principles of international law”.



4. Cuba


Territorial State(s): Syria


Non-state Actor: ISIL


Year(s): 2014 –


Official statements:


  • Statements of the Cuban representative before the UN Human Rights Council, February 28, 2016:

Taking into account recent cases in which we have seen a manipulation of the U.N. Charter as well as the double standard of the United States and other NATO members, we reject any attempt to undermine the sovereignty, independence, and territorial integrity of Syria.


5. Brazil


Territorial State(s): N/A


Non-state Actor: N/A


Year(s): 2018


Official statements:


  • Statement of Ambassador Mauro Vieira, Permanent Representative of Brazil to the United Nations, May 17, 2018


The tendency to associate most of the current threats and wrongdoings to non-state armed groups rather than to particular States has led to problematic interpretations of the law of self-defense. A few States have been arguing that self-defense could be applied as a response to "non-State actors", sometimes adding as a condition the criterion of "unwillingness" or "inability" of the territorial State to respond to those “non-State actors”. Brazil does not agree with such an interpretation.


  • Statement of Brazil during the United Nations Security Council’s 8262 Meeting, May 17, 2018


Given the spread of terrorism, there have been attempts to depart from the collective security system towards actions that reflect pre-Charter understandings. They have included reinterpretations of the law on self-defence as well as problematic readings on the letter of Article 2, paragraph 4, of the Charter. Some have been arguing that self-defence could be applied as a response to non-State actors, sometimes adding as a condition the criterion of unwillingness or inability on the part of the territorial State. Brazil does not agree with such interpretations.



6. Mexico


Territorial State(s): N/A


Non-state Actor: N/A


Year(s): 2016-2018


Official statements:


  • Statement of Mexico at the United Nations General Assembly Sixth Committee, October 12, 2018 (our translation)


My country considers that Article 51 of the Charter cannot be invoked to justify a response to an armed attack perpetrated by a non-state actor that has no relationship with the State, and, moreover, opens the door to undermining the territorial integrity of another State when the latter presents a lack of will or capacity (is "unable or unwilling") to act against said private entities.



Elena Chachko is the inaugural Rappaport Fellow at Harvard Law School. She is also an academic fellow at the Miller Institute for Global Challenges and the Law at Berkeley Law School. Elena’s scholarship at the intersection of administrative law, foreign relations law, national security law and international law has been published or is forthcoming in the California Law Review, the Georgetown Law Journal, the Stanford Technology Law Review, the Yale Journal of International Law, and the American Journal of International Law Unbound, among other publications. It has won several awards, including the 2020 Mike Lewis Prize for national security law scholarship, the Harvard Law School Irving Oberman constitutional law writing prize, and the Harvard Law School Mancini writing prize. Elena previously held fellowships at the University of Pennsylvania’s Perry World House, the Harvard Kennedy School’s Belfer Center, and the Harvard Weatherhead Center. She received her doctoral degree from Harvard Law School. Prior to her doctoral studies, Elena clerked for Chief Justice Asher D. Grunis on the Supreme Court of Israel. She has also worked at the United Nations Office of Counterterrorism and the Israeli Ministry of Foreign Affairs, where she focused on arms control and non-proliferation of weapons of mass destruction.
Ashley Deeks is the Class of 1948 Professor of Scholarly Research in Law at the University of Virginia Law School and a Faculty Senior Fellow at the Miller Center. She serves on the State Department’s Advisory Committee on International Law. In 2021-22 she worked as the Deputy Legal Advisor at the National Security Council. She graduated from the University of Chicago Law School and clerked on the Third Circuit.

Subscribe to Lawfare