Chapter VI. War

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.

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.

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 the State, the freeing of the unjustly oppressed, the refusal of infidel states to allow the Gospel to be preached in their dominions. There is considerable difference of opinion as to whether certainty of the existence of a sufficient cause is required or not for the lawfulness of a war. Some divines hold that a probability of right is sufficient, for with such a probable right a private person may commence an action at law, and states should not be in a worse position than private persons in the prosecution of their claims. However, on account of the grave public evils connected with war, and because it is unlawful to deprive another of what he possesses on the ground that it is only probably mine, it would seem that at least a more probable right or even a moral certainty of right is required on the side of the state that begins the war.

(c) There must be an upright intention of advancing the cause of good or preventing evil. Mere delight in the excitement of war, or the desire of showing one’s prowess or obtaining promotion, would not justify war.

When the end of the war has been sufficiently obtained the victorious party should be ready to make peace on proper guarantees being given.

Where conscription exists or soldiers have already enlisted before the outbreak of war, they are not bound to make inquiries about the origin of the war in order to satisfy their consciences of its justice; they may presume that their country is in the right unless it is evident that it is in the wrong, and in doubt they are bound to obey the commands of their lawful superiors. If the war is clearly unjust it only remains for the conscientious soldier to abstain from inflicting unjust damage on the enemy, otherwise he will be a co-operator in injustice. Volunteers who had not enlisted at the outbreak of war are bound to satisfy their consciences as to its lawfulness before they take any part in it, just as they are bound to form a morally certain conscience about the lawfulness of any action that they undertake, as we saw in the Book on Conscience.

In a just war all means that conduce to the end of gaining victory over the enemy are lawful, provided that they are not against the law of nature and international law or agreement. International agreements are only binding if they are faithfully adhered to by the adverse party. In modern war it is the practice to spare the persons and property of non-belligerents as far as possible. In naval warfare not only the enemy’s ships of war may be attacked and taken, but his merchantmen, and any British vessel or vessel of an ally trading with or acting in the service of the enemy at war with England, or any neutral vessel engaged in the same way or in the carriage of contraband, and blockade runners, may be captured and made lawful prize by duly commissioned British ships. war on land is restricted to arms, ammunition, Booty of and military provisions and stores. Private property on land is no longer liable to capture and confiscation, but requisitions and contributions of men for labour, money, victuals, etc., are still levied on the invaded territory by duly qualified officials of the invading army. Beyond these limits, or at least beyond what is permitted by lawful authority, it is not allowed to appropriate private property belonging to the enemy.