For every follower of Christ the slaying of a fellowman is a terrible thing. That one nation should have to march out against another and compel it by sheer force to refrain from evil and do good seems quite contrary to the spirit of our Master. His Sermon on the Mount, so full of its high idealism of "turning the other cheek," of submitting to rather than repelling violence and giving the coat to him who takes the cloak, strikes the whole note of the Gospel yet can hardly be made to fit in with the traditional practice of Christian nations. The figure of Christ in its austere gentleness rebukes the swaggering truculence of actual Christians. It is true that there are phrases, too, in the New Testament which imply the opposite, startling and broken expressions about swords, not peace, as the gift He gave; injunctions to sell clothing and to purchase weapons; metaphors about war within the family, and parents and children set in fierce opposition: even as a child, it was predicted of Him that He should cause sorrow to His Mother, and that many should fall as well as rise in Israel on His account. But these do not seem at all to disturb the even tenor of His other teaching. Through all their violence and fierceness still echoes the gentle voice that bade men learn of Him, for He was meek and humble of heart; and the octave of Beatitudes are surely the true notes of His perfect harmonies, for the Law of Fear has at last given way to the Law of Love not the fierce slaying of the enemies of Israel, but the conversion of their hearts to the Lord their God.
But just as we have had to realize that it is possible to be angry and yet not to sin, so it is also possible to make war and yet not sin. To grasp how this can be, for the word "war" substitute the expression "employment of physical force." Now here it is obvious that the very observance of law requires physical force as a necessary adjunct. Legislation is worse than useless unless it can be enforced; and to enforce legislation is quite simply to employ force in the carrying out of its enactments. We may not personally obey the Acts of Parliament or Congress because of the policeman, but the policeman is essential to the Parliament in case we do try to disobey. For the same reason it is futile to oppose arbitration to " the employment of physical force," since the weakness of arbitration consists precisely in this that it has no soldiers at its back to carry its decisions into effect. The Hague Tribunal, while merely a tribunal, will be a standing travesty of peace: consequently even if international wars were abolished, international law would still have to be enforced by international police. Armies and navies will be for ever necessary, at least to carry out the awards of an international judiciary. It follows, then, that the employment of some sort of physical force may not be denounced as unchristian in itself. Force and law are necessary for righteousness. Hence when the Church blessed the Crusades, she simply turned war from its evil course; she did not destroy, but tried to sanctify it.
While therefore war, whether as a protection or a punishment, must always be necessary in this sinful world, very much may be done to mitigate it. The Church herself insists upon three conditions to be fulfilled before any war can be called just: (a) the matter of the quarrel must be grave, for the price of it is the most costly of all prices; (b) all other means of adjusting the difficulty must have been tried, because physical force is the final and ultimate method of affording either protection or punishment; (c) there must be some considerable hope of success. This last condition sounds at first cynical, in that it appears to justify all rebellion and only rebellion that is successful. But the real meaning of the proviso is that it is foolish to spill human life and undertake terrible risks of enterprise, unless there is some chance of good being eventually effected. If it is impossible to right the wrong, then it is foolish of me and unjust to others if I rouse a whole people and end by leaving their condition worse than it had been: I am forcing on them an evil which can have no reasonable justification. Then, too, it is incumbent upon all who are in any sense responsible, to take care that the fever for war is not fanned for political purposes, still less out of party politics. In matters where the consequences are so appalling, especial care and deliberation are required, even when the cause itself is righteous. Wars of aggrandisement, wars of partition, wars that are based only upon religious differences cannot bring ultimate peace. My influence for justice must necessarily be limited; but the united influence of each is supreme.
- text taken from Meditations for Layfolk by Father Bede Jarrett, O.P.