One of the few moral ideas about warfare that is generally agreed upon is that the use of armed force can be justified in the cause of national self-defense. This aspect of traditional 'Just War' doctrine is widely accepted by public opinion and is enshrined in international law, including the Charter of the United Nations. David Rodin's remarkable and original book mounts a powerful attack on this idea. His method is that of moral comparison. The tradition justifies a right to national self-defense as a parallel to the right of self-defense possessed by an individual person, a right which in certain circumstances can allow the use of lethal force. It is this supposed parallelism—'the domestic analogy', as it is called by Michael Walzer, a defender of the tradition—that Rodin criticizes.
In the first part of his book, he examines the basis of a personal right to self-defense, and carefully identifies conditions in which that right can justify the use of lethal force. In the second part, he argues that these conditions have no sufficient parallel in the national case. One question his argument takes up is whether it is the nation as such or its individual people that are supposed to figure in the analogy. Defenders of the tradition, Rodin points out, have notably disagreed with each other about this, and neither answer, he argues, will deliver what the supposed analogy requires. There is a further question of what is being defended—autonomy? a culture? a way of life? Again, what moral difference will it make if the government which is attacked is at war with some of its own people? There are further arguments based on general matters of fact. For instance, it is true of very many armed conflicts between states that each party can make a case that it is defending itself, or pre-empting aggressive action by the other.
Rodin builds a very powerful case against 'the domestic analogy'. He might be expected to end up with a pacifist conclusion, but he does not do so. Rather, he argues for the possible moral acceptability of armed force brought against states in police actions; though in his view this ultimately calls for the presently Utopian ideal of a universal state.
Although Rodin refers to international law and to historical examples, and he is fully aware of the brutal circumstances of actual life which 'realists' in these matters have in mind, his argument is