Catholic Teaching Concerning a Just War

Editor’s Introduction: Catholic doctrine is never an “untimely” thing. However, certain doctrines come to the fore from time to time due to circumstances in the Church and the world. Presently, there is a “perpetual war for perpetual peace,” as one clever commentator quipped, which brings the Catholic doctrine of the just war into the spotlight — or it should, anyway. The sad reality is that, not only do very few understand this doctrine, most don’t care to know. Slogans, not doctrine, guide their thoughts.

Catholics are neither pacifists nor war hawks. “My country right or wrong,” or “Kill them all, let God sort them out” is just as un-Catholic as the position of a Quaker or hippie who thinks that war is intrinsically evil. We have principles which guide us through these extremes. Regarding slogans, it must be said that with top-ranking military officials telling the public that “killing is fun,” we have entered a stage of ideological barbarism which would alarm an aggressive Moslem-slaying Crusader of the ages of Faith.

The scope of the following article is very limited. It is not a controversial piece. It is not “applied theology.” It simply advances the basics. But these are the principles from which a practical application must be made. Our copy editor — a man who likes thoroughness — reproached me with the inadequacy of this piece in the face of modern warfare’s present realities. There are, indeed, a host of issues to be addressed: “weapons of mass destruction” which do not discriminate between combatant and non-combatant; women in combat positions; wars of sheer aggression; so-called “preventive” wars; US military personnel putting themselves into harm’s way for the good of the anti-American, anti-Catholic, and deeply racist state of Israel; etc.

We cannot address all these things in one short article. In lieu of that, we will make a recommendation. Light in the Darkness Publications has just come out with a two-volume opus on the war in Iraq, Neo-Conned , and Neo-Conned Again , collections of essays by Catholics and some non-Catholics applying the just war doctrine to present realities. Included among the contributors are personal acquaintances of this editor, men who have deeply ruminated the traditional social teaching of the Church, and who have served this country as officers in the military, one of them having served as a Green Beret in Vietnam.

War: Who can escape it? The media surrounds us with vivid reminders — on every nightly newscast, in every daily newspaper — images of destroyed property, broken bodies, family members overcome with grief. The onslaught is overwhelming. Human nature being what it is, overexposure to anything has its down side. If we are not directly affected by the violence, we eventually become immune to it. To those of us who feel safe and secure, what is one more dead soldier, one more dying child, one more fatherless family? For most of us, this is a necessary psychological response. In the safety of our protected environment, too much influence of this type can cause us to become depressed and discouraged. As a result of this emotional torpor, it is easy to begin to accept the belief that all conflict is evil — all war is to be condemned. Those terrible images of death and destruction seem so unnecessary. Why can’t people get along with one another? Why must they maim and kill? Overloaded with images of death and destruction, extreme pacifism can be a real temptation for a modern American Catholic. Yet, is condemnation of all war the true Catholic teaching?

Our Lady has told us without qualification that war is a punishment for sin. Few knowledgeable Catholics would doubt this for a second. Most people are also familiar with the adage, “War is hell.” Anyone who has experienced the terrible reality of war will readily confirm this to be the case. On the other hand, from the earliest times, the Church has taught that there is such a thing as a “just” war. When we consider that “just” is defined as conformable to divine or human laws and “good” is defined as having excellent qualities, pious, moral, we appear to have a problem. In effect, the terms “good” and “just” can be used interchangeably. This seems to imply that war can also be good. How is it possible that war can be good and bad at the same time? Is that not an obvious contradiction?

In this article, we will examine what the Church has traditionally taught concerning war and when it is justified. We will look at the elements that are necessary for a war to be called “just.” Finally, we will apply these principles to recent conflicts and discuss the morality of fighting for one’s country at our point in history.

Basic “Just War”Theory

Moral theologians define war as “a contention carried on by force of arms between sovereign states or communities having in this regard the right of states.” St. Augustine (A.D. 354-430) provided the basics of what is today’s Catholic teaching concerning warfare. That the concept of this state of violent conflict may be more clarified in one’s mind, the African doctor first contrasts “warfare” with “peace,” defining the latter as “the tranquility of order.” Peace is the unity of wills rather than a harmony of opinion. He demonstrated from Holy Scripture that Christ did not condemn war. Further, in the Old Testament certain wars were commanded by and directed by God Himself. Ecclesiastes 3:3 states plainly that there is “a time to kill.” The primary point was that peace was the goal, even if there was no other means to achieve it but by force of arms.

In the thirteenth century, St. Thomas Aquinas provided the three minimum conditions for a war to be considered “just”:

  • It must be waged by lawful public authority in defense of the common good;
  • It must be waged for a just cause;
  • It must be waged with the right intention — not vengefully nor to inflict harm.

St. Thomas added that it is not lawful for bishops or clerics to fight in a war; they may participate, but in a capacity which is consonant with their orders, such as ministering to the spiritual and medicinal needs of the soldiers. It is not right that the same hands that are consecrated to shed Christ’s blood should shed the blood of men. When safeguarding the common welfare, it is lawful to conduct a just war even on Sundays and holy days. Ambushes are allowed since they are not wrong in themselves.

Following St. Thomas, further refinements were made of his basic tenets. Despite development, St. Thomas’s ideas remain the foundation for the discussion of a just war. This has been evident in the current debate, within Catholic circles, over whether or not the United States’ war on Iraq is just.

The Source of the Right to Conduct War

Natural Law 1 is the source of the right to conduct war. The Catholic Encyclopedia (1912 edition) states that right as follows: “Every perfect 2 right, i.e., every right involving in others an obligation in justice [or a deference thereto] to be efficacious and, consequently, a real and not an illusory power, carries with it at the last appeal the subsidiary right of coercion. A perfect right, then, implies the right of physical force to defend itself against infringement, to recover the subject matter of right unjustly withheld, or to exact its equivalent, and to inflict damage in the exercise of this coercion wherever, as is almost universally the case, coercion cannot be exercised effectively without damage.” In other words, a sovereign power can resort to force of arms in order to exercise or defend its legitimate rights. Without the ability to use coercion to defend them, all other rights are just illusions.

War, in general, is divided into two classes — defensive and offensive. The first occurs when an armed attack has been made on a peaceful society, and arms are taken up in self-defense. The second class, offensive war, is the armed response to an injurious action other than a direct attack or invasion. Theologians have traditionally held that no special moral justification is needed when taking up arms to defend oneself from an armed attack. Although the attacked nation is subject to certain moral limitations when conducting the war, waging war in response to a direct attack is to exercise the natural right of self-defense — pure and simple.

The other class, offensive (also called “aggressive”) war needs to be justified. It is to this second category that the following conditions of a just war must be considered before deciding to go to war. All of these conditions must be present at one and the same time.

  • Just cause: force may be used only to correct an evil to the nation or community that is lasting, grave, and certain.
  • All other means of securing or defending its rights must have been shown to be impractical or ineffective.
  • There must be a serious probability of success.
  • Proportionality: the expected good to be achieved must be greater than the destruction and disorder that will be caused by the use of force. (Modern weapons of mass destruction must be seriously considered when evaluating this condition.)
  • Force may be used only as a last resort.

First, a “just cause” means that the community or nation is in danger of suffering damage that is lasting, grave, or certain. It is not justified to wage war in order to gain new territory, increase wealth, subjugate other peoples, or to expand the sphere of influence. This does not mean that it is necessary for the aggressor to strike first. A moral certainty that aggression will occur is sufficient. This is particularly important when an aggressor can attack from a distance with little or no warning. An injury to the natural right of the nation to existence, self-preservation, property, or free action within its own sphere may be sufficient cause for making war.

Second, force may be used when all peaceful alternatives have been tried and found to be ineffective or impractical. These include diplomacy, embargoes, blockades, covert actions, raids, and other means that avoid an all-out war. It is not necessary that all of these be tried and found wanting. It is sufficient that they are seriously considered and, if found to be impractical, are not actually employed.

Third, there must be a serious prospect of success. Of course, there is no way to know the outcome of a war in advance. Many factors can change the outcome — other nations unexpectedly entering the conflict, loss of public will, internal betrayal, new political considerations, change in government, etc. What is required is the serious possibility of success before war is engaged.

Fourth, the foreseen evil consequences caused by the war must not be greater than the evil to be eliminated. War always kills people and damages property. With the advent of modern weapons of mass destruction, the damage to people and property can be enormous — out of all proportion to the end that might be achieved by a war. In addition, war creates economic burdens and changes the alignment of national alliances. Those who are responsible for deciding to go to war must do their best to attempt to foresee if the damage caused by starting a war will be greater than if things are allowed to run their course or other methods of resolving the conflict, however inadequate, are employed.

Fifth, force should be used only as a last resort. This is similar to number two above. All other peaceful means should be examined and, if possible, utilized before the decision is made to go to war.

Although a just war is based upon the natural law of self-defense, a nation that conducts a war is very different from an individual who defends himself against an aggressor. An individual, intending to defend himself, is justified if he unfortunately kills his assailant in the process. However, an individual is not justified if he takes matters into his own hands and begins to kill foreigners whom he views as enemies of his country, state, or city. The decision to go to war is reserved to the sovereign state — specifically, to those who govern the state. The state has an obligation in justice to its citizens to use physical force in order to protect or defend their individual rights. When foreigners impinge upon these rights, the state must protect its subjects. To do otherwise would deny justice to the state’s subjects. It is up to the state itself to determine when to exercise its right of coercion — subject to the limitations and considerations outlined in this article. The Church has conceded to the State the full natural right of declaring war.

Limitations on the Conduct of War

In either class of armed conflict, defensive or offensive, certain rules must be followed. First, sacred places must not be harmed, unless there is a real military necessity.

Second, noncombatants such as civilians, priests, chaplains, medical personnel, and people who are neutral must not be deliberately targeted. To willfully kill these people is murder. On the other hand, the indirect killing of noncombatants or neutrals falls under the natural law of self-defense. Such killing is unavoidable and unintended. When innocent people are unintentionally killed during a war, it involves the principle termed the “double-effect.” That is, a morally good or justified action may be performed even when it is known that an additional effect will be produced that is bad. The doer intends the good effect, but not the bad. Also, the good effect is produced independently of the bad, not as a result of it. 3 Prisoners of war should not be tortured or placed as human shields to protect one’s own troops. Although they must be fed and treated humanely, it is not necessary that they be treated better than one’s own soldiers. Citizens must never be deliberately targeted. When prisoners are taken, they must not be harmed even if the enemy fails to make promised concessions or violates previous agreements.

Third, private property must be respected and may only be taken when necessary to conduct the war. Looting is not justified. On the other hand, the enemy’s military property may be confiscated or destroyed. Public, non-military property may also be occupied or confiscated.

Fighting to gain only a stalemate is immoral. Although only lawful means should be used, the goal of the war should be victory. If the war is justified and the object of the war is to restore peace, then anything less than victory is not just. To put one’s subjects through the suffering that accompanies any war, when the conditions at the end of the war will be little different from those before the war began, is gross injustice.

When deciding to go to war, the sovereign should use the same degree of moral certitude as that applied by a jury trying a suspect for a capital crime. The case for war should be beyond a reasonable doubt. If the government decides to go to war, it will, in effect, sentence many people to death.

Although it is not right for an individual to attempt to wage war, individual provinces or states of a larger nation may do so if its citizens are in danger from a foreign power. Normally, an individual state would not take up arms on its own unless there is not enough time to wait for the country to wage the war, or if it is determined that assistance could not or would not be provided by the nation. For example, if Mexico suddenly invaded Arizona, the State could wage war in defense of its citizens, even if the country as a whole did not participate.

Before the war is undertaken, if possible, an ultimatum should be issued to the opposing country offering final terms and a last opportunity to make satisfaction or the required apology. Innocent foreigners and ambassadors should be given the opportunity to settle their affairs and leave the country within a reasonable amount of time.

It may be justified to go to war with a third party in order to assist the inhabitants who are being tyrannized by the reigning government or to help a weaker country that is being bullied by a stronger one. It may also be lawful to make war on another nation in order to impose order on one that is in a state of chaos and lacks a civilized government that benefits the people. On the other hand, if the uncivilized country has an existing government that is orderly and at peace, war is not lawful; nor is war justified merely to gain a commercial advantage, to maintain the “balance of power,” or the prevention of difficulties at home.

How do we Decide when it is Right to Fight for Our Country?

The Church teaches that only the sovereign has the authority to make the decision to go to war. Unless there is some good reason to think otherwise, individuals may presume that their sovereign’s decision is justified. Individuals rarely know all of the facts that are considered in the decision. They are not privy to a great deal of information that may be sensitive and confidential.

Individuals who are not certain that the cause is just may have some choice in whether they serve; however, if they are called to fight for their country, they should do so, even if in doubt. The presumption is usually on the side of the government. On the other hand, volunteers who are not already enlisted may choose not to offer their service to a belligerent unless they are certain that the cause is just. Even if the government is not justified, the individuals are usually of good faith because they normally lack a full understanding of the facts or merits of the controversy.

When one reviews Catholic writings concerning a just war (or even the majority of the Protestant and secular writings), the serious turpitude of our nation and of our modern world becomes glaringly apparent. Before the late twentieth century, moral theologians presumed some basic level of Christian morality when discussing the topic. For example, sacred places, members of religious orders, and clerics were to remain unharmed. Whenever possible, fighting should be avoided on Sundays and Holy Days. Prisoners were to be treated humanely. Non-combatants were not to be intentionally harmed. A basic idea of Christian justice was assumed. Men were considered answerable to their Creator. While warfare was not condemned, it was not glorified either.

Excessive pacifism in the face of a morally evil enemy was considered a grave sin. When facing an enemy that was committed to immorality and cruelty, to attacking Christianity, war was not only justified, but also virtuous. Motives for making war such as pride, jealousy, and greed were commonly recognized as immoral. While all moral writers recognized the terrible consequences of waging war, they avoided both extremes of unnecessarily glorifying it and condemning it out-of-hand.

When we examine the wars and smaller “police actions” of the past several decades, we are forced to conclude that our country, our Civilization, has effectively abandoned its Christian heritage. We’ve seen the use of atomic weapons and aerial bombing firestorms that target innocent civilians, the torture and slaughter of prisoners, wars intentionally fought to a stalemate, conflicts prolonged for personal and political gain. All of these terrible crimes have been the result of the diminished influence of the Catholic Church. As the Western World faces the resurgence of the violent frenzy called the “Islamic jihad ,” it has no means to fight against it, other than that of brute force. With no truly moral grounds for initiating a war and no universally recognized guidelines for conducting one, the chance for success in the “war against terror” seems dismal, at best. These factors complicate the Catholic’s decision to fight or not.

With these considerations in mind, is it possible for a Catholic to fight for his country when he knows that it has become, effectively, a pagan empire? The answer is found in the principles of the just war. Even a pagan country can act in self-defense and, to a greater than lesser degree, fight for what is just and defend the rights of its citizens. The individual can presume that his government has, in general, followed the long-accepted principles of a just war, unless it is clearly not the case. If the motives and facts are unclear, he can presume in favor of his sovereign and fight for his country if necessary. Even if his country, while prosecuting a war, commits acts that are not morally justified, he can fight, if the overall cause seems to be good. Errors and excesses are part of every war, even if the cause is noble.

At the beginning of this article the question was posed, how is it possible that Our Lady would state, without qualification, that war is a punishment for sin, while the Church allows that war can be not only justified but virtuous. War is the result of our sinful, disordered nature. Sin, be it greed, lust, pride, envy, or any of the others, is the ultimate cause of war. On the other hand, the defense of what is good and true, of those who are helpless and whose God-given rights are violated is good — and virtuous. The Crusades were called by the Church for the defense of Christendom against the fierce onslaught of the Mohammedans. To fight for the defense of the One True Faith is required of all confirmed Catholics. Even as it is virtuous to defend the helpless, it can also be virtuous to assist one’s country in the defense of a weak ally against a more powerful, unjust aggressor.

Individuals who fight in a war, even if they are forced to serve on the side that is unjust, can be virtuous. If they intend to do what is just and they act in a manner that is in accordance with Catholic moral principles, they can gain grace and grow in goodness. If they fight, but not out of anger or vengeance; if they treat prisoners, non-combatants, sacred places and persons and property according to Catholic moral principles; they can actually grow in holiness while fighting for their sovereign. If they offer their lives to the service of Our Lord and Our Lady and treat both friend and foe with Catholic Charity, they cannot only grow in virtue, but also win others to the One True Faith — on and off the battlefield. They can baptize or pray with those in danger of death. They can practice any and all of the corporal and spiritual works of mercy — counseling the doubtful, comforting the sorrowful, visiting the sick, burying the dead, and so forth. If one reads the lives of the early Christian saints, he is struck by the number of soldiers in their august company.

One more serious matter needs to be considered. What is a Catholic to do if he chooses to fight for his country and, in the course of the war, is given an order to do something that he knows for certain is morally wrong or goes directly against his Catholic Faith? For example, let us say he is ordered to shoot down prisoners of war or destroy innocent non-combatants. God willing, he will never be faced with this choice. If it happens, however, that he must choose between obeying the order to commit a sin (or something he knows is unjust) or suffer the consequences of refusing to obey an order, the Catholic must choose to obey the higher law — that of God and of the Church. He may have to suffer severe personal consequences for his choice to obey God’s Law rather than the command to commit an immoral act. He could be court-martialed and even executed for disobeying a direct order. These are not easy decisions to make. Neither were these choices easy for the great martyr-soldiers like Saint Sebastian, Saint Joan of Arc, Saints Maurice, Victor, and the members of the Theban Legion, along with countless others who chose to remain faithful witnesses to the Truths of their Faith in the face of severe penalties — even death.

It is true that war is a punishment for sin. However, as with everything that is evil, a faithful Catholic, with the help of God’s grace, can bring good out of the evil. After all, we are members of the Church Militant. When we received the Sacrament of Confirmation, we became “soldiers of Christ.” The Church has excellent reasons for using these war-like phrases. In order to save our souls, we must “fight the good fight .” The reality is that our fallen world includes war. In the spiritual sense, in order to save our souls, we must wage war against Satan and his legions.

If enlisted or forced into service, we may have to participate in some way, or even fight, in a war. Catholics are not extreme pacifists. We can fight for our country, even with all of its increasingly pagan and anti-Catholic influences. However, we must do it as Catholics — just, moral, brave, practicing charity and putting God’s Law above all selfish considerations. We have seen that, while war is punishment for sin, some wars can be just — even virtuous. Further, it is possible that, as good Catholics, we can even be purified and sanctified during the chastisement of a war and through the challenging conditions such a terrible conflict forces upon us. If we remain true to our Faith, we can save our souls and the souls of others in the process.

Having concluded our brief look at Catholic teaching concerning a just war, it is important for us, as Americans living in the world as it is today to continue to do our part for peace in our nation and in the world. We owe it to our soldiers to pray for their safety and, most importantly, for their spiritual welfare. Whether our country engages in war or not, whether we serve or not, whether our relatives are enlisted to fight or not, we must pray for the conversion of our nation — every day — without fail. Only when our nation has become Catholic can we ever hope truly to fulfill the requirements for a just war. Our Lady said that war is punishment for sin. She also gave us the solution — the daily Rosary and the collegial consecration [the Pope and bishops] of Russia, by name, to her Immaculate Heart. Let us pray the Rosary, each and every day, for the conversion of America and the consecration of Russia. We owe this to our nation, our children, and ourselves. As good Catholics we know that Our Lady is our only hope.


1 Natural Law is the universal, practical, obligatory judgments of reason, knowable by all men as binding them to do good and avoid evil. St. Thomas states it is “nothing else than the rational creature’s participation in the eternal law.”

2 “Perfect” means complete or whole; fully in act; having all the actual qualities and good attributes that are requisite to its nature or kind.

3 An example of using a bad action to attempt to produce a good effect was dropping the atomic bomb on Nagasaki and Hiroshima. The United States desired to kill a large number of innocent citizens with the intended result of ending the war with Japan. Although the intent to end the war was a good, the deliberate killing of civilians for this purpose was not justified and was, therefore, murder.