Symposium on Erin Pobjie’s Prohibited Force: The Meaning of ‘Use of Force’ in International Law – Introduction

[Alonso Gurmendi is Fellow in Human Rights and Politics at LSE and Contributor Editor at Opinio Juris]

At Opinio Juris we are extremely happy to present the present online symposium on friend-of-the-blog, Erin Pobjie’s recent book, Prohibited Force: The Meaning of ‘Use of Force’ in International Law (available on open access here). In this fascinating contribution to the law on the use of force, Erin addresses a fundamental paradox: that despite the fundamental importance of the prohibition of the use of force between states, there remains genuine uncertainty in the international and academic community about what this term actually means. Thus, instead on tackling the meaning of “armed attack” or “aggression”, Erin studies use of force itself; as she notes: “scholarly analysis of the meaning of an unlawful ‘use of force’ leaves unclear the actual content and meaning of a prohibited ‘use of force’, namely, its elements, the relationship between those elements, and the lower threshold of prohibited force”.

This often understudied analysis is important and has significant practical implications. As the book sets out, “the definition of prohibited force and its lower threshold have direct relevance for the right to self-defence and the lawful responses available to States to security threats”. Since self-defence is not triggered by all unlawful uses of force – only those that arise to the level of an armed attack – then “[t]he lower threshold of a prohibited use of force affects the size of the gap between prohibited force under article 2(4) and an armed attack giving rise to a right of self-defence under article 51 by making the gap larger (if article 2(4) has a low threshold) or smaller (if article 2(4) has a high threshold)”. Addressing this “gap” means reducing existing legal uncertainty in international relations.

Prohibited Force is an essential contribution to this complicated and uncertain legal outlook, proposing an original framework to identify unlawful uses of force, especially those at the lower end of the gravity spectrum. It ultimately argues that “an unlawful ‘use of force’ is not a concept (with a checklist of necessary elements) but rather a type, characterised by a basket of elements which must not all be present and which must be weighed and balanced to determine whether the threshold for the definition is met and an act is an unlawful ‘use of force’ under article 2(4) of the UN Charter”.

To celebrate the launch of this excellent book, we have collected a group of amazing scholars who will tackle different themes found within the book. The symposium opens today with Professor Claus Kreß, who offers an introductory reflection on Erin’s book. Tomorrow, Adil Haque addresses the book’s main argument in the context of self-determination. On Wednesday, Tomohiro Mikanagi, focuses on the application of Erin’s theory to the acquisition of territory by force while Andrew Clapham tests the book’s central premise in light of so-called “anomalous cases”. On Thursday, the issue of “anomalous cases” is taken up again by Alejandro Chethman, and James A. Green reflects on Erin’s main proposition – the “Type Theory” approach to the meaning of use of force. The symposium closes on Friday, with Erin’s response.

Before closing this introduction and inaugurating the symposium, I wated to acknowledge the fact that, despite our efforts to present the most diverse panel possible, including scholars from different parts of the world, personal backgrounds and scholarly traditions, we were unable to secure women colleagues in the roster. We reached out to five women scholars and quickly confirmed how the burdens of academic citizenship and administrative work fall disproportionately on them. Given these difficulties, we had to postpone the symposium on two occasions, as we tried to secure the right panel. After these delays, two women scholars agreed to contribute to the symposium, but due to these unequal burdens, they informed us they would need to decline participation last minute. Despite our efforts to find a suitable replacement, the last-minute nature of the situation meant we would need to postpone the symposium once again or cancel it. We only decided to move forward once it became clear that further delays would be prejudicial to the timeliness of the symposium and prevent us from showcasing Erin’s important work effectively. I apologise for these failings in organisation, which are entirely my own and not Erin’s, and want to reassure our readers that we did not take this decision lightly. We thought it would be better to note these gender inequalities in academia, rather than keep suspending or cancelling our showcasing of a talented scholar’s work.

I truly hope you will enjoy this symposium and look forward to the discussion.