4.44 May Christians enlist in the army or wage wars?

The Lord proclaimed “Blessed are the peacemakers” (Matthew 5:9). He called for peace of heart and denounced the immorality of anger which is a desire for revenge for some evil suffered. He also denounced hatred which leads one to wish evil on one’s neighbor. These attitudes, if voluntary and consented to in matters of great importance, are mortal sins against charity. [CCCC 480]

Earthly peace requires the equal distribution and safeguarding of the goods of persons, free communication among human beings, respect for the dignity of persons and peoples, and the assiduous practice of justice and fraternity. [CCCC 482]

This responsibility belongs to the prudential judgment of government officials who also have the right to impose on citizens the obligation of national defense. The personal right to conscientious objection makes an exception to this obligation which should then be carried out by another form of service to the human community. [CCCC 484]

Even during a war the moral law always remains valid. It requires the humane treatment of noncombatants, wounded soldiers and prisoners of war. Deliberate actions contrary to the law of nations, and the orders that command such actions are crimes, which blind obedience does not excuse. Acts of mass destruction must be condemned and likewise the extermination of peoples or ethnic minorities, which are most grievous sins. One is morally bound to resist the orders that command such acts. [CCCC 485]

Because of the evils and injustices that all war brings with it, we must do everything reasonably possible to avoid it. To this end it is particularly important to avoid: the accumulation and sale of arms which are not regulated by the legitimate authorities; all forms of economic and social injustice; ethnic and religious discrimination; envy, mistrust, pride and the spirit of revenge. Everything done to overcome these and other disorders contributes to building up peace and avoiding war. [CCCC 486]

Peace is the consequence of justice and the sign of love put into action. Where there is peace, “every creature can come to rest in good order” (Thomas Aquinas). Earthly peace is the image of the peace of Christ, who reconciled heaven and earth.

Peace is more than the absence of war, more than a carefully maintained balance of powers (“balance of terror”). In a state of peace, people can live securely with their legitimately earned property and freely exchange goods with one another. In peace the dignity and the right of self-determination of individuals and of peoples are respected. In peace human coexistence is characterized by brotherly solidarity. [Youcat 395]

Paul says, “Be angry but do not sin; do not let the sun go down on your anger” (Eph 4:26).

Anger is initially a natural emotion, a reaction to perceived injustice. If anger becomes hatred, however, and someone has ill-will toward his neighbor, this normal feeling becomes a serious offense against charity. All uncontrolled anger, especially thoughts of revenge, are detrimental to peace and destroy “the tranquility of order”. [Youcat 396]

Jesus places a high value on nonviolent action. He commands his disciples: “do not resist one who is evil. But if any one strikes you on the right cheek, turn to him the other also” (Mt 5:39).

He rebukes Peter, who wants to defend him with force: “Put your sword into its sheath” (Jn 18:11). Jesus does not call his disciples to take up weapons. He remains silent before Pilate. His way is to take the part of the victims, to go to the Cross, to redeem the world through love, and to call the peacemakers blessed. Therefore the Church, too, respects people who for reasons of conscience refuse to be part of the armed services but place themselves at the service of society in some other way. [Youcat 397]

The Church strives for peace but does not preach radical pacifism. Indeed, no one can deny either the individual citizen or particular governments and alliances the fundamental right of armed self-defense. War is morally justifiable only as a last resort.

The Church unmistakably says no to war. Christians should do everything possible to avoid war before it starts: They oppose the stockpiling of arms and trafficking in weapons; they fight against racial, ethnic, and religious discrimination; they work to put an end to economic and social injustice and thus promote peace. [Youcat 398]

The use of military force is possible only in an extreme emergency. There are several criteria for a “just war”: (1) Authorization by the competent authority; (2) a just cause; (3) a just purpose; (4) war must be the last resort; (5) the methods used must be proportionate; (6) there must be a prospect of success. [Youcat 399]