CHAPTER VI
ON WAR
i. WAR, or an armed struggle between sovereign states, is defensive when it is undertaken to resist attack; otherwise it is offensive when undertaken to avenge an injury, or in vindication of a right.
2. When a quarrel has arisen between two sovereign states, if it is clear that one of the parties is in the wrong, it is bound to make reparation to the offended party. In national quarrels, however, this is seldom the case; as a rule, international disputes are matters of great complexity, and it is very difficult to say on which side right and justice lie. In ordinary cases, then, defensive war is always lawful, for if individuals have the right of self-defence the same right must a fortiori be conceded to a sovereign state. Even offensive war is lawful, provided that certain conditions be fulfilled. This is the certain teaching of Catholic theology, although the Church constantly prays to be delivered from all wars and from the terrible evils to which they give rise. Although war is a great evil, yet it is sometimes a hard necessity if still greater evils are to be avoided. For there is no higher tribunal to which sovereign states can have recourse to settle their disputed rights, and nothing is left but the final arbitrament of the sword. In modern times arbitration courts have been established, and they have done useful work, but cases arise in which their aid cannot be invoked with effect.
3. The conditions on which war may be lawfully waged are three:
(a) The public authority of a sovereign state is requisite to declare war, for war, except in just defence, cannot be made on private authority, or by a less than sovereign state; for private persons and subject states can always have recourse to higher authority for the vindication of their rights.
(b) A just and weighty cause is necessary, for the cause should be such as to outweigh the grave evils and risks which always accompany war. Such causes, in the judgement of divines, are: the retaking of a conquered country or rebellious province, the avenging of a grave insult or injury offered to
