Can an occupier invoke the right of self-defence against terrorism stemming from territories which it occupies? In its Advisory Opinion on the Legal Consequences of the Construction of a Wall in the Occupied Palestinian Territory the International Court of Justice responded to this question in the negative. This article critically analyses the reasoning presented by the Court concerning the specific question of the right of self-defence, not least in the light of the fact that it was harshly criticized by a number of judges in their individual opinions and by the Supreme Court of Israel in the subsequent Mara'abe (Alfei Menashe) case. It is also suggested that the issues discussed in this article, such as state responsibility for an armed attack, the principle of effective control, and the interplay between jus ad bellum and jus in bello, loom beyond the scope of the concrete question and concern more theoretical issues of international law.