PIL Discussion Group: The ICJ’s Conception of an Illegal Occupation in the 2024 Palestine Advisory Opinion

In its 2024 advisory opinion on the Legal Consequences arising from the Policies and Practices of Israel in the Occupied Palestinian Territory, including East Jerusalem, the International Court of Justice ruled not only that Israeli policies and practices in the occupied territory systematically violated international law, but also that the occupation as such has become illegal and that Israel had to withdraw from the occupied territories as rapidly as possible. The Court’s finding that Israel engaged in a sustained abuse of its position as an occupying power, through annexation and frustration of Palestinian self-determination, was central to its reasoning. So was its holding that the legality of the occupation was to be judged against the jus ad bellum. This talk, based on a draft article, unpacks the concept of an illegal occupation, as understood by the Court and in the individual opinions of its judges. It argues that, as matter of the jus ad bellum, only the right to self-defence could even potentially justify Israel’s continued occupation. Curiously, however, the Court does not mention self-defence in its opinion, although it preoccupied many of the judges writing separately. The talk shows that there are five ways in which the opinion’s approach to the occupation’s ad bellum illegality could be understood. It then argues that two approaches to the occupation’s ad bellum illegality can be defended: that the occupation could not meet the necessity and proportionality criteria of lawful self-defence, and that even a valid self-defence claim can be vitiated by a predominant ulterior purpose.

Marko Milanovic is Professor of Public International Law at the University of Reading School of Law, and Director of the Global Law at Reading (GLAR) research group. He is co-general editor of the ongoing Tallinn Manual 3.0 project on the application of international law in cyberspace and the Special Adviser on Cyber-Enabled Crimes to the Prosecutor of the International Criminal Court. He is also co-editor of EJIL: Talk!, the blog of the European Journal of International Law, as well as a member of the EJIL’s Editorial Board. Professor Milanovic was formerly Professor of Public International Law and Co-Director of the Human Rights Law Centre at the University of Nottingham School of Law, and served as Vice-President and member of the Executive Board of the European Society of International Law.  Professor Milanovic held visiting professorships at Michigan Law School, Columbia Law School, Deakin Law School, the University of Bologna, the University of the Philippines College of Law, Union University Belgrade Faculty of Law, and the Geneva Academy of International Humanitarian Law and Human Rights.