Pope Pius XII on wars of aggression

Every war of aggression against any ordinance which God gives to man in the interests of peace and bids him respect and endorse, preserve and defend, is a sin and a crime. It is an attack upon the Majesty of God, the Creator and Orderer of the World. If any people threatened with, or already the victim of, an unjust aggression be minded to think and act in a Christian way, it cannot remain in a passive indifference. All the more does the solidarity of the family of peoples forbid the other members to behave like simple onlookers in an attitude of unconcerned neutrality.

Who can ever measure the harm done in the past by such indifference, so far removed from Christian feeling, towards aggressive wars? How pointedly it has given proof of the lack of security among the "great" and, above all, among the "little". Has it, on the other hand, brought any advantage at all? On the contrary, It has only reassured and encouraged the authors and favourers of aggression, by forcing single peoples, abandoned to themselves, to a necessary and indefinite increase of their armaments.

Resting upon God and upon the order established by Him, the Christian will for peace is, accordingly, strong as steel. It is of a temper very different from the mere humanitarian sentiment, too often nothing but a sensitiveness which detests war only because of its horrors and atrocities, its havoc and its dire results, but not also because of its injustice.

In such a sentiment, hedonistic and utilitarian in character, and materialistic in origin, there is wanting the firm foundation of a strict and unconditional obligation. It forms the kind of soul in which the empty sham of compromise takes root, the attempt to save oneself at the cost of others, and in every case the success of the aggressor.

So true is this that neither the consideration of the sorrows and evils following from war, by itself, nor the exact balancing of action and advantage, suffice for a final decision whether it is morally lawful or, in a given concrete case, morally binding, to resist the aggressor (supposing always a well-founded likelihood of success).

One thing is certain: the precept of peace is of Divine right. Its end is the protection of things that constitute the good of mankind, in so far as it is the good of the Creator. Now among these are some so important for human society that their defence against unjust aggression is beyond question fully lawful. The United Nations as a body are bound to defend them, having the duty not to forsake the nation assaulted.

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