Chatham House Paper on Aiding and Assisting by States

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When states engage in armed conflict today, it is often the case that they do so with some support from other states. The same is true with respect to counter-terrorism efforts. That support may come in many forms: from being part of a coalition that engages in actual fighting; to logistical support that enables the fighting to take place; to supply of weapons; to intelligence sharing; or capacity building in one shape or another. One only has to look at the network of state assistance to other states on all sides of the conflict in Syria, and also in Yemen. A couple of weeks ago Chatham House published a paper –  “Aiding and Assisting: Challenges in Armed Conflict and Counterterrorism” – that I would like to commend to readers. The paper, authored by Harriet Moynihan who is Associate Fellow in the International Law Programme at Chatham House, seeks to set out:

“a clear statement of the law on aiding and assisting as it stands, with particular regard to its application in situations of armed conflict and counterterrorism. The paper also aims to provide guidance to governments on best practice in their cooperation in armed conflict and counterrorism, taking into account the legal and policy issues raised by the various rules in this area.” (para. 6)

A central question addressed in the paper is: when will a state that provides assistance that is used by another state to carry out actions that are wrongful in international law, responsible for assisting that wrongful act? The paper addresses this issue by first considering (in Chapter 2) the general rule that is established with regarding to aiding and assisting in Article 16 of the International Law Commission’s Articles on the Responsibility of States 2001. Chapter 3 then pays some attention to more specific rules of international law that deal with aiding and abetting, eg Common Article 1 of the 1949 Geneva Conventions, some treaties dealing with weapons transfers and some applicable rules of international humanitarian law.

Much of the analysis in Chapter 2 deals with the tricky question of the mental element that must be fulfilled in order to establish a breach of Article 16 of the ILC Articles on State Responsibility. The paper provides an excellent overview of the issues, starting with the tension between the text of Art. 16 that requires knowledge and the ILC’s own commentary that seems to require that assistance be given “with a view” to, or with the intent of, facilitating the commission of wrongful act. The clarity in the analysis is extremely useful, setting out the key issues methodically and examining the arguments in detail. There is much to be learned here. On the question of whether knowledge alone suffices, the paper states that: “On the whole, the better view appears to be that intent is a necessary part of Article 16, in addition to knowledge.” [para. 64] However, it then states elegantly that “[k]knowledge or virtual certainty that the recipient state will use the assistance unlawfully is capable of satisfying the intent element under Article 16, whatever its desire or purpose”. [para. 70] On this view, purpose is not required, intent is but knowledge will usually satisfy the intent requirement. In this way, the gap between the calls for a standard based on knowledge and that based on intent is virtually (if not entirely) eliminated, as long as we accept that purpose is not part of the intent requirement.

While the paper deals mainly with assistance by states to other states, some parts of it (in both chapters 3 & 4) address issues that arise with respect to assistance by states to non-state actors. The final chapter sets out some strategies and recommendations for governments to reduce the risk of assisting unlawful acts by other states. For governments this may well be the most important chapter as it sets out practical steps and decision making processes that they can adopt in order to avoid being responsible for aiding unlawful conduct.

In addition to the paper, I would also commend to readers the mini-forum on the paper that was recently held on the Just Security blog. That forum included an introduction to the paper by Harriet Moynihan, with responses from Shaheed Fatima, Miles Jackson, Alex Moorehead, and Gabor Rona and Ryan Goodman.

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Vladyslav says

November 28, 2016

Dear Dapo,

Thank you for bringing this excellent paper by Harriet Moynihan (Chatham House) to the attention of EJILTalk readers. For those readers who may not already be aware, Chatham House will hold an event launching the paper on 6 December 2016 (

Ms. Moynihan has done an excellent job of analysing the level of knowledge or intent that must be shown on the part of the purportedly complicit State. I have analysed elsewhere the statements and practice of States and international organisations on the question of knowledge/intent underlying the scope of Article 16 ARSIWA, and on balance have argued that the test of actual knowledge of the circumstances of the internationally wrongful act is sufficient, without any need to prove intent of the complicit State vis-à-vis the principal wrongful act (whether it is construed as a purpose or knowledge-based intent).

Among many parts of the paper that are to be praised for a skilful technical analysis, I have three brief comments on the areas where I believe that issues raised in the paper could benefit from further discourse. These areas are: (i) the material content of assistance; (ii) the causal nexus between aid or assistance and the principal wrongful act; and (iii) the opposability of the obligation breached, or as the paper calls it, ‘the double obligation rule’.

First, in relation to the positive character of assistance, I am concerned about the conclusion presented in the paper that complicity can only arise out of positive actions (paras 19-20). The key test in practice is whether a given aid or assistance has actually facilitated the commission of an internationally wrongful act. Whether the conduct that amounts to aid or assistance is an action or an omission is irrelevant to the possibility of triggering responsibility for aid or assistance. Allowing complicity to capture both actions and omissions is consistent with the foundations of the law of responsibility and the constituent elements of an internationally wrongful act. The resulting breadth of possible qualifying aid or assistance is counter-balanced by the requirements of actual knowledge of the principal wrongful act and a causal link between the aid or assistance and the principal wrongful act.

Second, there remains large degree of ambiguity in literature, both terminological and substantive, in relation to how causal considerations at the level of the origins of responsibility should be handled in situations of complicity and, separately, in the context of the implementation of responsibility for complicity (ie whether the traditional test(s) of causation between the breach and the injury are even appropriate to cases of complicity). This is not a reproach to the paper, as in paragraph 9 it specifically excludes any considerations of implementation of responsibility for complicity, but it is an area that could benefit from further analysis. The Second Report of the Special Rapporteur Arangio-Ruiz on the question of how multiple causes should be handled is particularly instructive as it provides some guidance on how the burden of reparation should be allocated between multiple wrongdoers. It is questionable, however, whether complicity can be treated as one of such intervening causes where an injured party seeks reparation from the principal wrongdoer, and whether the reparation due from the principal wrongdoer is necessarily attenuated due to complicity.

My third and final comment is that – the question of opposability of the obligation breached is dealt with very succinctly in the paper (paras 28-29) and appears to assume that the position taken by the ILC in Article 16(b) of the ARSIWA is a correct one. I have argued in my book that this requirement (which was an afterthought at the second reading of the ARSIWA, instigated by comments of Sweden and the Netherlands, albeit later retracted by the latter) is not only overly restrictive to the practical effect of responsibility for complicity but also does not find support in practice and opinio juris.

The above comments should in no way detract from the well-researched and significant contribution of this paper to the study of complicity in the law of international responsibility.

Finally, and with apologies for the shameless self-promotion, my recently published monograph on complicity may be of interest to readers as it discusses many of the issues covered in Ms. Moynihan’s paper as well as some others, including the responsibility for complicity in respect of international organisations and the question of implementation of responsibility for complicity (

Thank you.