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Reconciling new interpretations of the UN Charter with the customary international law on the use of force

Published on November 26, 2019        Author: 


In a recent lecture, published as a post on this blog, Professor Dapo Akande analysed the diversity of the rules on the use of force in international law and the implications for the evolution of the law in this area. In this post I wish to address one issue arising from this discussion but not directly addressed in Dapo’s lecture: the impact of changes to the UN Charter on the customary international law rules on the use of force.

In his lecture, Dapo argues persuasively that there are structural difficulties surrounding the evolution of Charter rules, and that these could be avoided if UN members were to interpret the UN Charter through subsequent practice under Article 31(3)(b) VCLT so that a ‘Uniting for Peace’ resolution of the UN General Assembly ‘would be deemed not to be a breach of the prohibition of force under Art. 2(4) in the same way that a Council resolution authorizing force would have that effect.’ However, while this route would avoid the obstacles Dapo discusses that make it difficult to imagine customary international law bringing about a change in the Charter rules on the use of force, it raises the opposite question: how would modification of the Charter rules impact the customary prohibition on force?

As clarified by the ICJ in Nicaragua (Merits, para 179), customary law continues to exist and apply separately alongside even identical treaty provisions. Since the customary and treaty prohibitions exist independently, even if the Charter were to be interpreted so that force authorised through Uniting for Peace was no longer considered a breach of Article 2(4), this interpretation of the Charter wouldn’t automatically change custom to match. A priori, force lawfully authorised by the General Assembly under the Charter would therefore still be in violation of the customary prohibition on force. One could argue that the new treaty rule would simply prevail over the customary prohibition to the extent they conflict, but this seems difficult when the customary prohibition is probably also a jus cogens norm. Indeed, it seems rather that the purported interpretation of the Charter would – by analogy with a new treaty amendment conflicting with jus cogens which would presumably be caught by Article 53 VCLT – be invalid. Read the rest of this entry…


France Speaks Out on IHL and Cyber Operations: Part II

Published on October 1, 2019        Author: 

In the first part of this post I discussed the position paper’s articulation of the views of France on the applicability of IHL to cyber operations, on the classification of armed conflicts, and on their geographical scope in the cyber context. In this part I will examine the position paper’s views on the concept of “attack,” on the conduct of hostilities and on data as an object.

The Meaning of the Term “Attack”

The issue of the meaning of the term “attack” has occupied center stage from the very inception of legal thinking about cyber operations during an armed conflict. It is a critical one because most key IHL “conduct of hostilities” rules are framed in terms of attacks – it is prohibited to direct “attacks” against civilians or civilian objects (distinction), an “attack” expected to cause collateral damage that is excessive to the anticipated military advantage is prohibited (proportionality), parties must take precautions in “attack” to minimize harm to civilians (precautions in attack), etc.  These prohibitions, limitations, and requirements beg the question of when a cyber operation qualifies as an “attack” such that the rules govern it.

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France Speaks Out on IHL and Cyber Operations: Part I

Published on September 30, 2019        Author: 

The French Ministry of the Armies (formerly the Ministry of Defense) has recently released Droit International Appliqué aux Opérations dans le Cyberspace (International Law Applicable to Operations in Cyberspace), the most comprehensive statement on the applicability of international law (IHL) to cyber operations by any State to date.  The position paper dealt definitively with many of the current unsettled issues at the forefront of governmental and scholarly discussions.

This two-part post builds on an earlier post at Just Security in which I examined the position paper’s treatment of the relationship between peacetime international law, including that set forth in the UN Charter regarding uses of force, and hostile cyber operations. The focus here, by contrast, is on France’s views as to how IHL applies in the cyber context. Key topics addressed in the paper include the applicability of IHL in cyberspace; classification and geography of cyber conflict; the meaning of the term “attack” in the cyber context; the legal nature of data during an armed conflict; and other significant IHL prohibitions, limitations, and requirements on cyber operations.

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