Abstract: This book describes and explains the basic tenets of just war theory and gives a precise, succinct, and highly critical account of its present status and of the most important and controversial current debates surrounding it. Rejecting certain traditional, in effect medieval assumptions of just war theory and advancing a liberal outlook, it argues that every single individual is a legitimate authority and has, under certain circumstances, the right to declare war on others or the state. It also argues that just cause cannot be established independently of the other criteria of ius ad bellum (the justification for entering into war), except for right intention, which the book interprets more leniently than is traditional. Turning to ius in bello (which governs the conduct of a war) the book criticizes the doctrine of double effect and concludes that insofar as wars kill innocents, albeit as ‘collateral damage’, they cannot be just, but at best justified as the lesser evil. The book gives particular attention to the question why soldiers, allegedly, are legitimate targets and civilians not. Discussing four approaches to the explanation of the difference, it is argued that the four principles underlying them should all be taken into account and outlines how their comparative weighting can proceed when applied to concrete cases. The resulting approach does not square the distinction between legitimate and illegitimate targets with that between soldiers and civilians: this has extremely important consequences for the conduct of war. Finally, the book analyses the concept of terrorism, arguing that some forms of ‘terrorism’ are not terrorism at all and that, under certain circumstances, even terrorism proper can be justified.

Keywords: doctrine of double effect, innocence, jus ad bellum, jus in bello, just cause, just war theory, legitimate authority, non-combatant immunity, principle of discrimination, terrorism