prepared by Father Tom Knoblach, Ph.D.
Consultant for Healthcare Ethics, Diocese of Saint Cloud

Introductory Note: this brief summary only gives highlights of current Magisterial teaching on just war theory. It does not review the history or development of this teaching, does not consider contemporary theologians' comments on the teaching, does not review statistics, public opinion, or current international law related to war, and does not apply the teaching to any particular cases.

God's gift of peace is necessary for individual and social human development. This peace is more than just an absence of war, more than a precarious balance of power among adversaries. Rather, peace is a positive reality, the attainment of a just social order that safeguards and fosters the basic human rights of each person. Peace is the fruit of justice and charity.

Throughout human history, conflict, violence, and war have marked our common life. These fruits of anger and envy defy God's desire for peace, and have often dramatically shaped the destinies of individuals and whole nations. Ultimately, our faith tells us that war arises as an effect of original sin, a deeply-rooted alienation of the human person from God, self, and others. While the human person, created in the image of the Truine God, is naturally social, the power of sin distorts this sense of community and makes us into competitors and adversaries for social goods.

While peace remains the ideal goal of the human community, experience amply demonstrates that aggression, violence, and injustice often affect us. Catholic teaching acknowledges the right and at times duty of communities or nations to defend themselves in an effort to re-establish peace when it has been disrupted by the actions of others.

The Catechism of the Catholic Church expresses contemporary Church teaching on war quite clearly and directly.

2307 -- The fifth commandment forbids the intentional destruction of human life. Because of the evils and injustices that accompany all war, the Church insistently urges everyone to prayer and to action so that the divine Goodness may free us from the ancient bondage of war (see Gaudium et spes 81, 4).

2308 -- However, as long as the danger of war persists and there is no international authority with the necessary competence and power, governments cannot be denied the right of lawful self-defense, once all peace efforts have failed (Gaudium et spes 79, 4).

This teaching clearly speaks of the genuine need for legitimate self-defense as the prerequisite for actions of war. This is an extension of the principle of legitimate self-defense for individuals, in which the threat of harm must be grave, real, and immediate; there are no alternatives to violent resistance; and the force used to resist the harm must be only that which is necessary. Thus Catholic teaching would in no way justify initiating violent conflict, attacking others without due provocation, or in other ways inciting war. Further, it would oblige us to first seek non-violent means to resolve conflict, such as diplomacy, economic sanctions, and trade embargoes.

Due in part to its understanding of the effects of original sin on the human condition and on the necessity to struggle against evil in the world, Catholic tradition has been consistent in interpreting the Gospel as allowing a Catholic to participate in and support a war for national defense in certain carefully delineated conditions. The Catechism summarizes them neatly:

2309 -- The strict conditions for legitimate defense by military force require rigorous consideration. The gravity of such a decision makes it subject to rigorous conditions of moral legitimacy. At one and the same time:

• the damage inflicted by the aggressor on the nation or community must be lasting, grave, and certain;
• all other means of putting an end to it must have been shown to be impractical or ineffective;
• there must be serious prospects of success;
• the use of arms must not produce evils and disorders graver than the evil to be eliminated by their use. The power of modern means of destruction weighs very heavily in evaluating this condition.

These are the traditional elements enumerated in what is called "just war" doctrine. The evaluation of these conditions for moral legitimacy belongs to the prudential judgment of those who have responsibility for the common good.

The Catechism also notes several other moral factors involved in the waging of war:

• public officials have the right and duty to impose obligations on their citizens necessary for national defense;
• military service can be a laudable contribution to the common good and the attainment of peace;
• conscientious objection must be allowed, although those who refuse to bear arms have the responsibility to contribute to the common good in some other way;
• the moral law remains in force, even during armed conflict; conditions of war do not justify violations of human life or dignity
• non-combatants, wounded soldiers, and prisoners must be treated humanely;
• one is morally obliged to resist orders to commit genocide;
• only combatants may be targeted for violent resistance; the indiscriminate destruction of whole cities or territories is never justified.

Again, these statements are at the level of principle. To apply these principles to specific cases is always more difficult. An adequate understanding of a particular situation requires an investigation in the reasons for attack by the aggressor nation, which often attacks due to its belief that it has suffered previous injustice.

The justification of any war absolutely requires that its sole aim be to re-establish peace and defend the rights of the innocent. Ultimately, the peace we seek to establish on earth among and within nations is a foreshadowing of the Messianic peace that Christ alone can bring. Nonetheless, it remains an essential duty of all Christians and all people of good will to seek and strive after peace.