Episode 12 – Tom Ruys on the Exercise of Self-Defense to Recover Occupied Territory

In this episode, I speak with Tom Ruys, Professor at the Faculty of Law, Ghent University, Belgium. We discuss a debate he recently sparked with a blog post on the question of whether states my invoke the right of self-defense to justify the use of force to recover previously occupied territory, looking specifically through the lens of the recent seizure of territory in Nagorno-Karabakh by Azerbaijan in a short sharp armed conflict with Armenia. Tom and his co-author, Filipe Rodriguez Silvestre, argue that the initial occupation (in the 1988-94 conflict in the case of Nagorno-Karabakh) cannot be characterized as a continuing armed attack, and that self-defense cannot justify the use of force to recover the territory. In a responding blog post, Dapo Akande and Antonios Tzanakopoulos of Oxford argue that such a use of force can indeed be an act of self-defense, and that Azerbaijan’s actions are in fact so justified — and so we explore the competing arguments. To start things off, however, we do discuss Tom’s seminal book, ‘Armed Attack’ and Article 51 of the UN Charter, both to lay the foundation for discussing self-defense in Nagorno-Karabakh, and to explore whether any of his positions have evolved since publication of the book ten years ago. Finally, we discuss briefly his recent work on economic sanctions, and the relationship between sanctions and the collective security regime. Not to be missed!


‘Armed Attack’ and Article 51 of the UN Charter: Evolutions in Customary Law and Practice (2010).

– “The Nagorno-Karabakh Conflict and the Exercise of “Self-Defense” to Recover Occupied Land,” Just Security, Nov. 10, 2020 (with Filipe Rodriguez Silvestre).

– “Sanctions, Retorsions and Countermeasures: Concepts and International Legal Framework,” in Research Handbook on UN Sanctions and International Law (Larissa van den Herik, ed., 2017).

Reading Recommendations:

– Craig Forcese, Destroying the Caroline: The Frontier Raid that Reshaped the Right to War (2018).

– Ian Urbina, The Outlaw Ocean: Journeys Across the Last Untamed Frontier (2019).

– Erika de Wet, Military Assistance on Request and the Use of Force (2020).