Home EJIL Analysis The Constructive Ambiguity of the Security Council’s ISIS Resolution

The Constructive Ambiguity of the Security Council’s ISIS Resolution

Published on November 21, 2015        Author: 
Security Council Adopts Resolution on Fighting ISIL

UN Photo/Loey Felipe

On Friday, the UN Security Council unanimously adopted resolution 2249 (2015), condemning a series of recent terrorist attacks by Islamic State (IS, ISIS or ISIL). The text of the resolution, together with statements of Council members, is available here. This resolution was proposed by France and superseded two competing earlier drafts by Russia. The resolution determines that IS constitutes “a global and unprecedented threat to international peace and security.”

But the resolution itself is, perhaps, an equally unprecedented measure by the Security Council. The resolution is clearly designed to provide legitimacy for the measures being taken, and to be taken, against IS by giving the Council’s imprimatur to such measures. In particular, the resolution is worded so as to suggest there is Security Council support for the use of force against IS. However, though the resolution, and the unanimity with which it was adopted, might confer a degree of legitimacy on actions against IS, the resolution does not actually authorize any actions against IS, nor does it provide a legal basis for the use of force against IS either in Syria or in Iraq.

The main operative paragraph of the resolution is para 5, in which the Council:

“5.   Calls 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 also known as Da’esh, in Syria and Iraq, to redouble and coordinate their efforts to prevent and suppress terrorist acts committed specifically by ISIL also known as Da’esh as well as ANF, and all other individuals, groups, undertakings, and entities associated with Al-Qaida, and other terrorist groups, as designated by the United Nations Security Council, and as may further be agreed by the International Syria Support Group (ISSG) and endorsed by the UN Security Council, pursuant to the statement of the International Syria Support Group (ISSG) of 14 November, and to eradicate the safe haven they have established over significant parts of Iraq and Syria;”

Before we attempt to decipher what this paragraph actually means, it is important to note that the resolution was not adopted under Chapter VII of the Charter. Or rather, the resolution does not use the “acting under Chapter VII” formula that is usually used to signal that the Security Council intends to take binding action, despite a couple of determinations in the preambular paragraphs about the existence of a threat to international peace and security, which (determinations) presumably are made under Article 39 of the Charter. In op. para. 1 of the resolution, the Council similarly “regards all such acts of [IS] terrorism as a threat to peace and security,” which again implicitly invokes Article 39. As the ICJ’s Namibia Advisory Opinion makes clear, the lack of reference to Chapter VII in a resolution does not mean that it is not to be regarded as binding nor does it mean that the resolution does not have operative legal effect. However, for the resolution to have those effects the Council must actually decide to do something or to authorize something.

What is particularly significant about Resolution 2249 is that it calls upon states to “take all necessary measures” (or more commonly “all necessary means”). As is well known, the expression “all necessary measures/means” when used in Security Council resolutions is code for the use of force. (For a rigorous overview of the Council’s practice in adopting Chapter VII resolutions, see this 2008 research paper at Security Council Report).

However, in this case, the Council does not authorize “all necessary measures,” nor does it decide that they be taken, but rather “calls upon” states to take such measures. This difference in language itself suggests that though the Council contemplates, and perhaps would even welcome, the use of force by states, it does not authorize such action. This lack of authorization is made clearer from the fact that the resolution calls for all necessary measures, “in compliance with international law, in particular the United Nations Charter”. This wording suggests that measures taken should comply with other rules of international law, including the jus ad bellum rules in the Charter. Thus, the resolution is to be seen as only encouraging states to do what they can already do under other rules of international law. It neither adds to, nor subtracts from, whatever existing authority states already have.

The use of the “all necessary measures” formula in an operative paragraph of a Council resolution which does not contain a decision appears to be novel. Its closest equivalent could be the rather dated resolution 221 (1966) which in its op. para. 5 “called upon” the UK government “to prevent, by the use of force if necessary,” of tankers bringing oil to Southern Rhodesia.

Similarly novel is the use of the “all necessary measures” formula in a resolution that does not state that it is adopted “acting under Chapter VII.” The closest equivalent to this formulation that we could find is resolution 2213 (2015), in which the Council expressed grave concern about terrorist groups in Libya proclaiming allegiance to IS and “reaffirm[s] the need to combat by all means, in accordance with the Charter of the United Nations and international law including applicable international human rights, refugee and humanitarian law, threats to international peace and security caused by terrorist acts”. Although that resolution was adopted under Chapter VII, it speaks of “all means” rather than “all necessary means”, and more importantly, the text just quoted was in a preambular paragraph, thus making it clearer that the Council was not authorizing anything, let alone the use of force.

Resolution 2249 is not the first time that a Security Council resolution has referenced the right of states to use force without itself authorizing such a use of force. Perhaps the best and clearest examples of such a referencing are resolutions 1368 and 1373 (2001) which reaffirm the inherent right of individual and collective self-defence after the 9/11 attacks. Those resolutions did not authorize US and allied actions in Afghanistan, but gave a Security Council stamp of legitimacy to them. Yet in those  post 9/11 resolutions the support was expressed in the preambular paragraphs and not in an operative paragraph. And it is clear what legal argument the Council or members of the Council were supporting with respect to Afghanistan – a self defence argument – even if the exact legal theory behind that argument remained contested and unclear.

Resolution 2249, on the other hand, is constructed in such a way that it can be used to provide political support for military action, without actually endorsing any particular legal theory on which such action can be based or providing legal authority from the Council itself. The creative ambiguity in this resolution lies not only in the fact that it does not legally endorse military action, while appearing to give Council support to action being taken, but also that it allows for continuing disagreement as to the legality of those actions.

Many states are already taking action against ISIS in Syria and Iraq, but they have different legal bases for doing so. The US-led coalition relies on consent with regard to action taken within Iraq, and the collective self defence of Iraq with regard to action taken in Syria. But the US, the UK and perhaps France (see here, here and the wonderfully ambiguous French letter to the Council in S/2015/745) have also made reference to individual self-defence with regard to strikes in Syria. Russia for its part (and presumably Iran) would rely on consent from the Syrian government with regard to their action in Syria, and like Syria regard actions taken by Western states in Syria without the consent of the Syrian government to be unlawful.

The US-led coalition will no doubt claim that resolution 2249 implicitly validates or confirms the legality of their current actions. In the UK, the Prime Minister is already using the resolution to build support for a decision to join the military action in Syria and it would not be a surprise to see the resolution used in response to concerns expressed about the legality of UK action in Syria. However, the resolution is also worded in such a way that it equally allows Russia, Syria and others to insist that the use of force in Syria without consent of the Syrian government is unlawful. This, therefore, is the resolution’s constructive ambiguity: it allows the major players in Syria to politically move closer together without departing from the legal positions that they had previously adopted, and without compromising their essential interests.

Two other minor points may be noted about resolution 2249. First, although the resolution speaks of “all necessary measures . . . on the territory under the control of ISIL also known as Da’esh”, it is not clear precisely what the necessary measures are supposed to be directed at. The single sentence in the paragraph is so long and convoluted that the objective that the measures are meant to achieve is not easy to decipher. It appears that states are called upon to take all necessary measures are to (i) redouble and coordinate their efforts to prevent and suppress terrorist acts committed by ISIL and others, and (ii) eradicate the safe haven they have established in Iraq and Syria.

Another point of note is that the resolution calls on states to take all necessary measures in compliance with international human rights law as well as international humanitarian law (and refugee law). This is standard language in relation to counter terrorism measures not involving the use of force (see, e.g., resolutions 2213 and 2214 (2015), Libya). However, here there is a call for a use of force but there is still a reference to international human rights law (IHRL). Although this may not have been the intention of the drafters, the fact the resolution covers and was intended to cover the use of force extraterritorially, but still included a call for compliance with IHRL, could be used as evidence that the even the Security Council has endorsed the view that IHRL does indeed apply to extraterritorial uses of force by states.

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57 Responses

  1. Lorand Bartels Lorand Bartels

    It is also relevant that Syria has now consented to use of force on its territory as per the resolution: “Welcome to everybody who finally woke up and joined the club of combating terrorists,” Syria’s U.N. Ambassador Bashar Ja’afari told reporters ahead of the vote on the French-drafted resolution (

  2. Duncan French

    Great blog Dapo and Marko – one question. As the operative clause neither decides not authorises, is it a “decision” for purposes of article 25 UN?

  3. Nigel Rodley

    Thanks to Dapo and Marko for the excellent instant commentary. Aren’t the resolution’s key words these: ‘on the territory under the control of ISIL …’, thus by-passing the need for consent of Syria (or Iraq) and so not requiring Security Council ‘authorisation’? It would not be enforcement action needing to override the will of a member state of the UN.

  4. Alessandra Asteriti

    I think the statement by the Syrian representative is as ambiguous as the resolution. What Syria certainly welcomes is the elimination of any reference to the Syrian government in negative terms (while surely preferring the Russian draft’s reference to supporting the Syrian government in its fight against terrorism). It (the statement) certainly is not an open endorsement of military action within Syrian territory by foreign forces without Syrian consent.

  5. Richard Hoyle

    Might this wording also provide some clarification on the boundaries of self-defence in this situation? In the Wall Opinion, the ICJ at [139] decides that “Article 51 of the Charter thus recognizes the existence of an inherent right of self-defence in the case of armed attack by one State against another State” and then went on to determine that it could not be relied upon by Israel because the attacks in question were essentially internal. The ICJ expressly distinguished this from the 9/11 resolutions. The ISIS resolution arguably puts Iraq more into the position of the 9/11 resolutions – providing support both in terms of a response to an attack which is partially internal, and regarding the “unwilling and unable” Syrian question, in terms of the language “eradicate the safe haven”. This would obviously have contingent consequences for collective self-defence arguments.

  6. Dapo Akande Dapo Akande

    Dear Lorand,

    I agree with Alessandra that the comment by the Syrian representative is too ambiguous to be regarded as consent.

  7. David Goddard

    I’m not sure too much can be read into the reference to IHRL. Given that it only calls upon States to redouble efforts, the resolution is directed at both Iraq and Syria, as well as other member States that choose to intervene. It is now uncontroversial (even for the United States) that human rights treaties continue to apply during armed conflict, though the relationship remains controversial. Both Iraq and Syria are parties to the ICCPR and CAT, so would both be bound to some extent by norms contained therein. Furthermore, nobody would disagree that certain specific provisions of CAT continue to apply extraterritorially during armed conflict for all States Parties (especially the obligation to criminalise acts of torture committed by nationals wherever committed), nor some norms of customary IHRL (e.g. the prohibition of genocide). While these are perhaps narrow points, in the past the Security Council has erred on the side of caution in referring to potentially applicable bodies of law. Note, for example, UNSCR 1851, which referenced both IHL and IHRL in the authorisation for member States to tackle piracy in Somalia. This was merely a recognition that the authorised action could plausibly engage IHL – certainly not that it inevitably would. Likewise here, on any view, IHRL could plausibly be engaged, without relying on any controversial notions of extraterritorial application.

  8. Dapo Akande Dapo Akande

    Dear Duncan,

    Thanks for that question. Decisions for the purposes of Art. 25 of the Charter are binding, as that Article says. The point that Marko and I were making is that operative paragraph 5 does not make a decision which is binding or which has operative legal effect, in the sense of authorising an action that could not otherwise be taken. Essentially, the task at hand is an interpretive one. The following points seem to us to indicate how one should undertake that task:

    – the language of the resolution is the starting point and will usually give an indication as to whether the Council has made a decision for the purposes of Art. 25. Some words (“decides”, “demands”, “authorise”) suggest that it has. Other words would indicate that it has not (eg “encourages”, “invites”).

    – In addition to the text, the drafting history of the resolution would be important if it gives an indication that the Council (or its members) intend the resolution (or part thereof) to be binding, or not binding.

    – The context in which the resolution was adopted and context of the key words (i.e other words used) would also be important indicators as to whether a decision has been made.

    – The words “calls upon”, which is what is used in this resolution, do not ordinarily indicate that a decision has been made or that an authorization has been given. However, one cannot rule out that those words do contain an authorization. For example, the resolution 221 (1966) on Rhodesia which we point to is probably a case where one would come to the conclusion that the UK was authorised to use force despite the words “calls upon” being used.

    – One important question would be whether the council was calling upon a state to do something that it could not otherwise do absent the resolution. Where that is the case, this is an indication that the Council intends to make a decision or to authorise something to be done. In the case of Rhodesia, UK would have had no power to stop vessels or to arrest them (as it was called upon to do by the Council resolution), absent the Council resolution and this was clearly evident. For that reason a Council resolution calling on the UK to take these actions must be taken as authorising action

    – In the case of the Syria resolution, the fact that the Council’s call for action is qualified by reference to compliance with international law and particularly by reference to the UN charter suggests that Council was not intending to confer a right not otherwise present

    – Also the limited drafting history we have from the press release shows France saying that action can be taken under Art. 51 suggesting that the drafter did not intend to confer a new power.

    For all those reasons, we would say no decision is made under Art. 25

  9. Dapo Akande Dapo Akande

    Dear Nigel,

    Thank you for the comment. Is the suggestion that because force is to be used only on territory not under the control of the government, that therefore the consent of the government is not needed for military action. It is not clear to me if that is the argument here but if so I would not concur with that view myself. The prohibition of the use of force in Art. 2(4) applies whenever the action is against the territorial integrity of a state, and that territorial integrity is deemed to be violated whenever force is used on the territory of another state without its consent. If the prohibition of the use of force did not apply because the government had lost control of some part of the territory that would be a very significant hole in the prohibition and open up the possibilities of ‘lawful’ uses of force across the globe. In any event, I don’t think states read Art. 2(4) in this way hence the desire by western states to get Iraq’s consent for the use of force against IS in Iraq.

  10. Dapo Akande Dapo Akande

    Dear Rick,

    One of the things about this resolution is that it can be read as providing support for so many different things and inconsistent things too! I don’t necessarily disagree with your analysis with regard to Iraq (that the threat it faces is artly external, thus opening the door to a collective self defence argument with regard to action taking in Syria). However, I don’t think the resolution provides greater support for that view, as compared with a view that says that there is no right of self-defence in response to attacks by non-state actors coming from across the border.

  11. Lorand Bartels Lorand Bartels

    Dear Alessandra, Dapo

    I should probably have said ‘apparently consented’. That said, I cannot see what is ambiguous in the statement.

    I would agree however with Alessandra that ‘It (the statement) certainly is not an open endorsement of military action within Syrian territory by foreign forces without Syrian consent.’ But not for the same reasons. The reason I would agree is that the statement constitutes (apparently) that Syrian consent.

    Where I think there is room for debate is whether the Syrian representative’s statement was intended to have legal consequences. But the meaning of the words seem to me entirely plain. I cannot see what else they can mean other than that Syria (or at least Syria’s Ambassador) has no objection – indeed it expressly ‘welcomes’ – foreign military action against ISIS on its territory.

  12. Kriangsak

    The reference to IHRL, refugee law, and IHL are to ensure that there be no gap in international law applicable to the situation at hand. I have heard the view of some international lawyers/States that ISIL is just an organized criminal gang whose resort to the various means of violence has not given rise to a situation of armed conflict, international or non-international. If so, IHL would not be applicable, according to this view, but IHRL would.

  13. Constantine Antonopoulos

    Dear dapo and Marco,
    This is a very interesting post. However, I would like to raise three points:
    First, is it necessary to explicitly make the reference “Acting under Chapter VII of the Charter” as long as there is the express determination focused on ISIS (rather than international terrorism in general) that it constitutes a threat to international peace and security? This appears to be quite a clear Article 39 UN Charter determination.
    Secondly, by “calling” (instead of “authorizing”) on all States to take all necessary measures against ISIS, does the SC not give its authority (and legitimacy) to military action as voluntary sanction going beyond the requirements of self-defence? That the action is to be restricted to the territory under the control of ISIS appears to indicate the exclusion of any measure that may be incidentally directed against the government of Syria (thus, excluding a repetition of what happened in Libya in 2011).
    Thirdly, does SC Res. 2249 (2015) not offer the States using force against ISIS under unilateral resort to force justifications a better alternative of lawful resort to force? The experience of Iraq and the (untenable) interpretation of SC Res. 678 (1990) (providing a temporally open-ended authorization) suggests that States prefer SC authorization to justifications pertaining to ulilateral uses of force. I think SC Res. 2249 (2015) offers as a matter of requisite consensus the possibility to the States currently using force against ISIS to fall in behind the SC and pursue their action under the umbrella of collective action.What is interesting, though, is that there is not a unified coalition acting against ISIS but that SC Res. 2249 may contribute to forming one ex post facto.

  14. Raphael Van Steenberghe Raphael van Steenberghe

    Thanks for this interesting post. I just would like to complement it. I fully agree with your interpretation of that quite exceptional resolution: it does not authorize UN member States to use force in Syria and does not take any position on the legality of the foreign interventions which are already taking place in Syria. Basically, the question of the legality of such interventions remains open.

    In that regard, I do not share the opinion that the French letter sent to the UNSC on 9 September 2015 (UN Doc. S/2015/745), before the terrorist attacks in Paris, is so ambiguous. The argument invoked in that letter is collective self-defence, even if the first paragraph of the letter indicates that “[the terrorist acts of the Islamic State] are also a direct and extraordinary threat to the security of France”. It is true that French politicians seem to have referred to individual (and even preventive) self-defence in some of their political speeches before the French population, i.e. at the national level. Yet, their concern was only to convince the French people about the necessity of a military operation, involving French soldiers, although such operation was very far away from France. Their aim was not to express the legal position of France with respect to the applicable international law rules regulating interstate use of force. Therefore, such national justifications should not be considered as reflecting the legal position upheld by France at the international level (as expressing its opinio juris), especially since the justification given at the international level is different.

    The fact that France relied on collective self-defence before the terrorist attacks in Paris is confirmed in a recent statement made by the permanent representative of France to the United Nations. This statement also confirms that France now considers that it can also act in individual self-defence in response to these terrorist attacks. The French representative, M. Delattre, indeed stated before the UNSC on 20th November:

    “Les attentats du 13 novembre ont constitué une agression armée contre la France. Nos actions militaires dont nous avons informé le Conseil de sécurité dès l’origine, qui étaient justifiées par la légitime défense collective, peuvent désormais se fonder également sur la légitime défense individuelle conformément à l’article 51 de la Charte des Nations Unies » (

    In addition, France has requested the application of Art. 42.7 of the UE Treaty, a mutual defense clause which contains an obligation for the EU member States to help any member which is victim of an armed aggression, in accordance with Article 51 of the UN Charter. No EU member State opposed the French request. This again confirms that the French authorities, supported in that respect by all EU member States, consider that the terrorist attacks in Paris amount to an armed attack under Art. 51 of the UN Charter and that France is allowed to respond to it in individual self-defence. This also an additional practice which confirms that armed attacks by non-State actors (in which no State is substantially involved) may amount to an armed attack under Art. 51 of the UN Charter.

    Yet, this does not necessarily mean than the legality of the actions undertaken by France and the other States in self-defence in Syria is undisputable. As already explained (in my post of 23 October 2015), some ambiguity remains due to the refusal of those intervening States to cooperate with the Assad regime and, therefore, questions arise with respect to the necessity of their actions. In this respect, I share the opinion that the statement of the Syrian representative just after the adoption of the UNSC resolution 2249, in which he said that “everybody who finally woke up and joined the club of combating terrorists [is welcome]” is not an open endorsement of any military operation conducted on the Syrian territory against ISIS, even without the consent of the Assad regime. It only seems to reiterate an offer made to Western States to coordinate their efforts with this regime and, therefore, with its consent.

  15. Dapo Akande Dapo Akande

    Dear Constantine,

    Many thanks for your comments. I agree with your first point that a resolution may be binding or authorise action even if it does not state that it is adopted under Chapter VII and we made this point in the post.

    With regard to your second and third points, please see my reply to Duncan French above with regard to how one should interpret the expression “calls upon” in tis resolution. Our view is that this resolution cannot be interpreted as providing authorization beyond such authorization as may already exist in international law.

  16. Alessandra Asteriti

    Dear Lorand
    yes, actually all this should be read in the background of US military operations (from the air) already taking place in Syrian territory with, one might say, Syrian acquiescence. So yes, is this a step forward by the Syrian representative, or is it an acknowledgement of the reality, or is it creating a new legal basis for action? I would say yes to the first two, no to the third.

  17. olivier corten

    Dapo and Marco, thanks for this very convincing comment! Even if some of its terms are not devoid of certain (constructive) ambiguities, the SC did not authorize any military action, as can be understood both from a comparison of the text with other previous resolutions and a reading of the debates having preceded the adoption of Res 2249 (2015). Two short additional comments, in view of some reactions posted above.
    In my view, the thesis of an implicit consent cannot be excluded, even if it is debatable. Since the aftermath of 13th November, France has begun to cooperate closely with Russia in the fight against ISIS. This means that, de facto, on the field, there is now a cooperation between Damas, Moscow and Paris (and probably with Washington) against the Islamic State. As far as I know, the Syrian authorities have (and this is quite understandable) not protested since against the French military operations. Against this background, when the Syrian representative expressly states “Welcome to everybody who finally woke up and joined the club of combating terrorists,” it would not be excessive to consider that there is an implicit consent, covering all the actions led with the cooperation of Russia (and indirectly Syria).
    Secondly, I think the ‘constructive ambiguity’ of the resolution also covers the ‘self-defence’ issue. On the one hand, France, the US and some other Western Powers invoke this argument for months to justify their strikes in Syria. But, on the other hand, we cannot find an element clearly consecrating it in the text of the resolution. The SC did not evoke self-defence, or Article 51 of the UN Charter, as it did for example in SC Res 1368 (2001). It rather evoked —referring not only to the Paris but also to Beirut, Sousse, Sinaï and Ankara—, ‘acts of terrorism’ constituting a ‘threat to peace and security.’ This (rather vague) terminology seems to reflect the traditional view taken by the Council in many other precedents when it prompted cooperation between States (and not actions led unilaterally from certain States against others) in the fight against terrorism. Of course, other interpretations of the resolution could be supported but, at the very least, it is difficult to deny that this text remains ambiguous. In my view, this reflects the current division among the UN Members about the possibility to invoke self-defence against a non-State actor, at least to the extent it implies crossing the boundary of a sovereign State without its consent and without its implication in any armed attack.

  18. Pierre d'Argent

    Dear Dapo and Marko,

    Thanks for this post on this important resolution and thanks to the various commentators.

    I agree that the binding character of the resolution (under chapter VII or Art. 25) is somehow beyond the point: the Resolution would not have been adopted if it were drafted as an authorization to use force, which would a contrario have meant that what happened before its adoption was illegal. Tabled by France and unanimously adopted, such outcome was to be avoided at all costs. And the contructive ambiguity indeed stems from the fact that it does not create any legal basis for the current air strikes by all parties. The reason for this is that there is no need for such a new, separate or additional, basis: all parties engaged in those operations consider (rightly or wrongly) that they have sufficient legal ground for doing what they do. And, on this, the resolution, without conferring a legal basis but also without choosing among the various alleged grounds for conducting air strikes, is not ambiguous. As rightly pointed in the post, by “only encouraging states to do what they can already do under other rules of international law … [the resolution] neither adds to, nor subtracts from, whatever existing authority states already have.”

    This being said, I think we should go one step further. Together with Nigel, I agree that the important words are “on the territory under the control of ISIL”. Also very important and powerful words are, I think: “and to eradicate the safe haven they have established over significant parts of Iraq and Syria”. “Eradicate” is quite a verb (“éliminer le sanctuaire” in the French version).

    Also, the resolution begins by “Reaffirming its respect for the sovereignty, territorial integrity, independence and unity of all States”.

    But if “Member States that have the capacity to do so” are “call[ed] upon” “to take all necessary measures” in order “to eradicate” the safe haven established by ISIS “on the territory under [its] control in Syria and Iraq”, and that doing so does not breach the territorial integrity of those latter States, is it not time to reconsider our usual understanding of the rules? In other words, is it still the opinion of States that (as Dapo replied to Nigel) “The prohibition of the use of force in Art. 2(4) applies whenever the action is against the territorial integrity of a state, and that territorial integrity is deemed to be violated whenever force is used on the territory of another state without its consent.”

    Honestly, in light of this resolution, our usual understanding needs to be revisited. What is not ambiguous in the resolution is that using force on the territory of Syria and Iraq in order to eradicate ISIS’ safe haven is NOT a use of force against the territorial integrity of those States, whatever the legal basis of the purported air strikes might be.

    The resolution is perhaps ambiguous for obvious political reasons, but it seems to me very clearly based on a distinction between the use of force ON a territory and the use of force AGAINST the territorial sovereign. Maybe that is new and disturbing and not in conformity with our traditional understanding of the rules, but we cannot fail to see that evolution. And, as positivists, we need to remember that the resolution was unanimously adopted.

    Therefore, I would not like the resolution being dismissed as “ambiguous” just in order to avoid questioning and thinking about the grammatical changes we need to confront.

  19. Marko Milanovic Marko Milanovic

    Many thanks for these last two comments, Olivier and Pierre. I would just add Pierre, that although I don’t think your reading of the resolution is necessarily excessive and implausible, our point about ambiguity is not one of avoiding confronting the hard questions. Rather, ambiguity here is a deliberate (and very effective) tool of law and policy-making. And whoever it was that drafted the resolution and op. para. 5 in particular is a true master of ambiguity as an art form, the Rembrandt of ambiguity, as it were – so kudos to them.

  20. Fred Kennedy NKUSI

    Dear Dapo and Marko,thanks for your incisive analyses, and those of commentors. I wish to underscore that Article 25 of the UN can be binding or non-binding, depending on the language used,whether it’s mandatory or exhortatory.

  21. Dear Dapo and Marko,

    Many thanks for a very thought-provoking post.

    When considering the value of the use of the phrase “calls upon” in the resolution, it is interesting to note that Chapter VII of the Charter itself suggests that the Security Council may “call upon” States to take certain action under Article 40 (provisional measures), Article 41 (sanctions), and Article 44 (utilising Member State’s forces). The inclusion of this phrase in the context of powers where the Security Council can both order and recommend action suggests to me that binding or non-binding nature of the phrase really depends on the context in which it was used.

    I recall that there was a brief discussion during the Palestine Question in 1948 when a resolution was adopted after changing language in the operative paragraph from “orders” to “calls upon”, with some States highlighting the recommendatory nature of the proposed measure in question.
    (see 302nd Meeting here

    and Security Council Repertoire, Cases 8 and 9, here )

    If “calls upon” in the context of Res 2249 (2015) does indeed highlight a recommendation by the Council, then this would include a recommendation to use force – since that is clearly the very purpose of the resolution. However, the Council is competent only under Chapter VII to make such a recommendation. The Council is not competent under Chapter VI, for example, to recommend the use of force.

    Article 39 guides the Council, once a determination of a threat to the peace or otherwise has been made (as it has done in Res 2249), to make recommendations or decide on measures under Articles 41 or 42. Since the Council does not take action under Article 41 or 42, the recommendation must either be a general Chapter VII recommendation within the meaning of Article 39, or a ‘provisional measure’ under Article 41. But it is unlikely to be the latter, because Article 41 explicitly applies to action before substantive recommendations are made “in order to prevent an aggravation of the situation”, without prejudice to the rights, claims, or position of the parties concerned.

    The Council first recommended the use of force during the Korean War early in the life of the Council
    (see ).

    But there is, of course, debate as to whether this is a recommendation to utilise collective self-defence, or a standalone basis to use force (i.e. an authorisation).

    Even if the Council is recommending a use of force that is already legal under self-defence, Article 51 only allows such force “until the Security Council has taken measures necessary to maintain international peace and security.” In this case, the Council decides to make a recommendation for the continuation of the use of force against ISIS and other “necessary measures” to prevent and suppress this threat, and eradicate their safe haven. By addressing the ongoing military action – even if not explicitly referring to self-defence – does the Council bring any ongoing self-defence into its purview under Article 51 through this Chapter VII recommendation? Is it now seized of the matter?

    Finally, the question that has been posed is whether a recommendation to use force equates to an ‘authorisation’ or a ‘decision’. But an ‘authorisation’, by its very nature, can be non-binding. It may not bind the states using force, but it may indirectly bind the State upon whose territory the force is being used. Hence why we have had ‘coalitions of the willing’ in the past – States have not always been ordered or compelled to take part in some of the Council’s enforcement operations. Perhaps the Council has only ever ‘recommended’ that they do so.

    Of course, the problem with this resolution is that it seems to have been drafted in such a way to make a compromise between the P5’s different interests and positions in Syria, and unfortunately all legal certainty was lost with that compromise. Perhaps, as you suggest, that was the intention.

  22. Marty Lederman

    Professor Corten writes of “the current division among the UN Members about the possibility to invoke self-defence against a non-State actor, at least to the extent it implies crossing the boundary of a sovereign State without its consent and without its implication in any armed attack.”

    I do not doubt that there is some anxiety or reluctance of some Members to come out and publicly *say* that the “inherent” right of self-defence can be invoked against a non-State actor that has engaged in an armed attack, even when it means using force in the territory of a sovereign State without its consent and without its implication in any such armed attack.

    But is there any actual evidence of a “current division”? Even putting to the side the Sept. 12, 2001 UNSCR, many states today are acting upon the view that the inherent right of self-defense extends to such a situation (e.g., the U.S., the U.K., Canada, Australia, France, Turkey, Russia (incursions into Georgia), UAE, Jordan, Iraq, Israel), and most of those have said so. Is there *any* state that has publicly adopted the opposite view?

  23. Raphael Van Steenberghe Raphael van Steenberghe

    I think that the “constructive ambiguity” not only covers the legal ground invoked by the US-led coalition, i.e. self-defence, but also the one raised by Russia, i.e. consent (which is explicit in a letter sent to the UNSC on 15 October 2015 [UN Doc. S/2015/792]). The legality of such argument, like self-defence, is not indisputable either, and this for two main well-known reasons. Firstly, the validity of the Syrian request may be called into question, as it only comes from the Assad regime, that is, Syrian authorities which have lost control over significant parts of the Syrian territory and which are no longer universally recognized as the legitimate government of Syria. The Russian airstrikes have been condemned by the National Coalition of Syrian Revolution and Opposition Forces (UN Doc. S/2015/750). Secondly, to the extent that Russia also targets moderate rebel groups that Syria include among the terrorists, it amounts to an intervention in an civil war, that many scholars consider as being prohibited under international law, regardless of whether this intervention is requested by the effective and legitimate authorities of the requesting State.

    The “constructive ambiguity” in relation to the legality of the interventions of both the US-led coalition and Russia derives from the sentence used in the resolution, that the necessary measures must be taken “in compliance with international law, in particular the United Nations Charter”. As both Russia and the US-led coalition consider that they are using force in Syria in full conformity with the UN Charter while intervening on different grounds, each of them can now argue that the UNSC resolution 2249 endorses its own intervention but, at the same time, they retain the possibility to interpret the resolution as a disapproval of each other’s interventions.

    Regarding the “within versus against” a State as a test for determining the scope of application of Art. 2, §4 of the UN Charter, this should indeed be further examined in my view. One should nonetheless keep in mind that there are many factual situations in which it is hard to determine whether force is used against a State or only within a State against non-State actors (such as armed groups). At least, in such situations, the identification of whom the intervening State intends to affect by using force should not only depend on its declarations/intent. In any case, resort to such a test, rather than the traditional one, makes the application of Art. 2, §4 less clear-cut.

    With respect to the impact of the UNSC resolution 2249 on the ongoing exercise of the right of self-defence by the US-led coalition, I think that it does not put an end to that exercise. Practice seems to show that even strong measures, such as an arms embargo (South Africa cases) or the authorization given by UNSC to use force (Iraq/Kuwait case), have not been viewed as the “necessary measures to maintain international peace and security” considered under Art. 51 of the UN Charter. Actually, according to state practice as well as the preparatory works of the UN Charter, those measures must effectively lead to the maintenance of the peace already restored. This is not the case here, at least not yet.

  24. Dan Joyner Dan Joyner

    Very useful piece, Dapo and Marko. I’m reminded of Michael Byers’ piece in Global Governance about Resolution 1441, in which he used a similar term “intentional ambiguity.” I think both resolutions in question were meant to do just what you say – bring everyone together on a text that they could all vote for, while preserving each state’s respective, and contrasting, views of the substantive legal issues.

  25. Courtney Hoyt

    Fantastic post! Are you aware of any previous UNSC resolution that has called on states to use ‘all necessary measures’ ‘in compliance with international human rights’?

  26. Jordan

    Patrick has made some excellent points. The phrase “calls upon” can logically involve an authorization, even a direction, and use of such a phrase in (1) the Charter, and (2) pre-Charter practice is informing. A straight-jacket textualist approach is not necessary or necessarily determinative.
    p.s. some disagree that use of force “on” foreign territory without the consent of that state is necessarily a use of force “against” the “territorial integrity” of that state.

  27. Jordan

    p.s. “Calls upon Member States … to take all necessary measures … in Syria and Iraq, to redouble and coordinate their efforts to prevent and suppress terrorist acts” should be interpreted with awareness of the acts of warfare that have been occurring (also as part of self- and collective-self defense) against the insurgent ISIS in Syria and Iraq by military forces of several countries. It impliedly sanctifies those efforts retrospectively.

  28. David Goddard

    Courtney –

    As I mentioned in my post above, UNSCR 1851 included the following (acting under Chapter VII):

    “…may undertake all necessary measures that are appropriate in Somalia, for the purpose of suppressing acts of piracy and armed robbery at sea, pursuant to the request of the TFG, provided, however, that any measures undertaken pursuant to the authority of this paragraph shall be undertaken consistent with applicable international humanitarian and human rights law.”

  29. […] Akande and Marko Milanovic have an excellent analysis of this provision on EJILTalk!  There, they note that this provision is unprecedented. […]

  30. […] the factual and the legal situation (on the, albeit ambiguous, Security Council Res. 2249/2015 see here), and both the Chief Prosecutor and the UN Security Council should take renewed action in […]

  31. Nicolas Boeglin

    Dear Dapo and Marko,

    Many thanks for this new post on this resolution and thanks to the different comments of our colleagues. If you have the link with access to the original draft presented by France, let us know and share it with all of us. In an official press release of UN, Russian delegate explained last Friday that explicit references to UN CHarter in 2249 Resolution result from Russia´s suggestions: ”M. Churkin s’est cependant félicité de ce que des amendements apportés à la demande de sa délégation, notamment les références à la Charte des Nations Unies, figurent désormais dans le texte”. Source:

  32. […] Em artigo publicado no Blog do European Journal of International Law (21/11), Dapo Akande & Marko Milanovic discutem a ambiguidade da resolução do Conselho de Segurança da ONU para combater o “Estado Islâmico” (EI). Apesar de ela sugerir algum apoio do órgão para o uso de força contra o EI, não o autoriza de fato nem estabelece um parâmetro legal para tal. A ambiguidade construtiva reforça tanto as posições legais da coalizão liderada pelos EUA quanto as da Rússia, mas ambas são aproximadas politicamente com a unanimidade da luta contra o EI. […]

  33. john r morss

    As one tends to take for granted, an excellent post by DA and MM. many thanks. I wonder Marko if you could at some time expand on your defence of ambiguity as smart (law- and)policy-making(there apparently is also Byers on this as noted above)? I think I see the point but it seems to raise more questions than it answers. Does the Security Council generate ‘policy’? What would this mean? Is this Higginsian realism’? Or is it Koskenniemian? or…. ? JRM

  34. […] But confusingly, despite the wording used in the text, Resolution 2249 (2015) does not purport to add to the legal authority already claimed by the states using force in Iraq (see the previous post by Dapo and Marko). […]

  35. […] The website for the European Journal of International Law (EJIL) promptly pointed out the obvious: […]

  36. Adrian Gallagher

    Historically, I feel it is worth noting that the UN Charter was constructed in an ambiguous manner in order to aid flexibility. The Covenant (1919) was viewed as too rigid, thus, the drafters of the UN Charter used ambiguous language to avoid this trap. See Paul Kennedy’s discussion of ‘artful language’ in The Parliament of Man. In this sense, ‘new’ ambiguous UN Resolutions perhaps should be seen as part of the norm rather than an exception to it. For as the authors state “The resolution’s constructive ambiguity: it allows the major players in Syria to politically move closer together without departing from the legal positions that they had previously adopted.” This, at least to me, seems part of existing UN practice rather than something new (though I accept questions of authorisation and lack of Chapter VII is interesting). This is not to say the authors are claiming this does in fact represent something new, but that we should simply put such ambiguity in historical context and also note that ambiguity is often referred to as a negative when in fact it has many positive aspects. On that last point see Widmaier and Glanville ‘The benefits of norm ambiguity: constructing the responsibility to protect across Rwanda, Iraq and Libya’, Contemporary Politics, 21:4. 2015. 367-383.

  37. Toby Fenwick

    Firstly many thanks to Dapo and Marko for a very thought provoking article.

    However, I’m a little confused, as I think that 2249 does significantly expand the authority to use force against ISIL/Daesh for those states who until now have not operating in Syria under collective self-defence at the request of the Assad regime.

    In making this case, it may be helpful to think about the practical implementation of 2249 by asking the question “what can I bomb”?

    Prior to the passage of 2249 there appear to be two firm and one contested basis for the use of force against ISIL inside Syria without the request of the Syrian Government. These are:

    i) As part of collective self-defence at the request of the Iraqi government;

    ii) As self-defence of the UK in response to a direct threat to the UK;

    iii) the humanitarian exception of R2P.

    Setting (iii) aside, both (i) and (ii) come with significant operational limitations.

    Under (i), the ISIL/Daesh target would have to be supporting attacks in Iraq, and in the much narrower case of (ii) there would need to be both a specific nexus with the UK and it would need to pass the Caroline immediacy test. In practical terms, either of these would severely limit the ISIL/Daesh targets that can be attacked.

    By contrast, OP5 of 2249 is expansive, and calls for all necessary measures “on the territory under the control of ISIL also known as Da’esh, in Syria and Iraq” – ie, including ISIL targets not involved in operations against Iraq, and therefore outside the limits of (i), and removes the UK-nexus and Caroline immediacy requirements in (ii).

    As a result, irrespective of the words of the Syrian Perm Rep, 2249 in effect provides Member States with the same basis for action inside Syria against ISIL/Daesh as an invitation for collective self-defence from the Assad regime – and it represents a potentially (very) significant increase in the number of targets that can be struck.

    If this is correct, then 2249 does authorise the use of force where it didn’t exist for all states before. As such, the Council can only do so under Art 41 whether it is explicit or not – and it is worth recalling that SCRs 82 – 85 authorised the UN’s largest use of force without mentioning Ch VII, Art 41 or even “all necessary means”.

    Thank-you again.


  38. It is difficult to see how UN member states responding to the Security Council’s call could try to “prevent and suppress terrorist acts” by ISIL on territory that it controls, or in particular “to eradicate the safe haven [ISIL] have established over significant parts of Iraq and Syria” without using military force.

    I would conclude that it does authorise armed force but does so by implication. If it does not, the resolution has little meaning. Any armed force would have to be in accordance with the other terms of the resolution.

  39. […] it was adopted provide a legal basis for the use of force against IS either in Syria or in Iraq (source). In short, the Resolution does not actually authorise […]

  40. […] military action more likely to be legal, the legality still depends upon the actions to be taken. Many argue that the UN security council resolution changes nothing, because it does not authorise the use of […]

  41. […] basis. The ambiguity of Resolution 2249 gives a lot of leeway to states (EJIL:Talk! provides a good analysis of the resolution[ii]). Regardless, the resolution could not legitimize previous military strikes, […]

  42. […] and member of the Executive Board of the European Society of International Law have examined the issue in depth and […]

  43. […] The website for the European Journal of International Law (EJIL) promptly pointed out the obvious: […]

  44. […] of the Security Council’s resolution 2249 (2015), that Dapo and I extensively addressed in our previous post, was used by the MPs during their […]

  45. Mark Serlin

    I am fundamentally confused about one thing, presumably because I am not a lawyer.
    The article states “…it is important to note that the resolution was not adopted under Chapter VII of the Charter. Or rather, the resolution does use the “acting under Chapter VII” formula that is usually used to signal that the Security Council intends to take binding action”

    Surely, the resolution does NOT use the “acting under Chapter VII” formula?

    It does say “in particular with the United Nations Charter” though. Is there a distinction between this and Chapter VII specifically?

    Respectfully, but struggling to understand,
    M Serlin

  46. Dapo Akande Dapo Akande

    Dear Mark,

    There was a typo in our piece. It should read “Or rather, the resolution does NOT use the “acting under Chapter VII” formula. It has now been corrected.

    Thanks for pointing this out!


  47. Mark Serlin

    You’re most welcome. Typos notwithstanding, thank you for an outstanding analysis in such readable style.

    Here in the UK last night 2249(5) was indeed cited as both an argument for action and due to the Chapter VII issue an argument against being compelled to act.

    I can see now how this has come about. My reading of it after your analysis is that the resolution is saying a state “may” act if they can swing it politically (so to speak) rather than “must” act.

    It is doubly interesting to me as the UNSC Charter was cited in Tony Benn’s speech in 1998 arguing against military involvement in Iraq, while 2249(5) was cited in his son Hilary’s speech arguing for military involvement in Syria. This is muddied somewhat by issues of unilateralism/multilaterlism in the respective cases, but is interesting nonetheless for that as both speeches are generally regarded as exceptional.

    They are here if you’re interested: (feel free to cut)
    Tony Benn
    Hilary Benn

  48. […] but also that it allows for continuing disagreement as to the legality of those actions». Cf. “The Constructive Ambiguity of the Security Council’s ISIS Resolution”, D. Akande y M. Milanovic, EJIL Talk, 21 de noviembre de […]

  49. […] militärischer Gewalt autorisiert oder nicht, ist bereits andernorts Vieles gesagt worden (hier und hier). Geht man nun, wie Sophia Müller, davon aus, dass der fehlende Verweis auf Kapitel VII […]

  50. […] but also that it allows for continuing disagreement as to the legality of those actions“. Vgl. “The Constructive Ambiguity of the Security Council’s ISIS Resolution”, D. Akande & M. Milanovic, EJIL Talk, November 21, […]