Abstract: This book explores the moral response to war and aggression within the context of self-defence. Two main projects are undertaken: to explain defensive rights in their most general form, and determine whether this explanation can be used as grounds for a right of national self-defence. It contends that although a coherent account of self-defence can be built around the idea of personal rights, the attempt justify war based on the conception of self-defence faces significant obstacles and ultimately fails. Self-defence has significant consequences for the entire enterprise of normative international relations, given its position as the centrepiece of the modern jus ad bellum (the rules specifying the conditions for a just war).

Keywords: self-defence, national-defence, war, aggression, international relations