Hungarian Conservative

Can a War Ever Be Justified?

Luca Giordano, The Defeat of Sisera (ca. 1692). Museo del Prado, Madrid, Spain
The inherent dilemma regarding the rules of engagement in a just war is that they tend to become either vague or restrictive when military operations fail to achieve victory or a ceasefire leading to peace.

This article was published in Vol. 3 No. 3 of our print edition.

Thomas Paine, the English-born political philosopher who supported revolutionary causes in America, once said: ‘War ought to be no man’s wish.’1 At the same time, referring to the American Revolution, he remarked: ‘We fight not to enslave, but to set a country free, and to make room upon the earth for honest men to live in.’2

There are those today who, given the brutality of what war entails, see no morality to it. Instead, such military exigencies are viewed as serving only the interests of the state, or, as in the case of Russian President Vladimir Putin’s invasion of Ukraine or the war in Darfur, Africa, where government forces continually attack civilians living there, those of the despot.

Yes, war is horrible, for in it, even if only to preserve innocent life, man must conform himself to take another man’s life. Yet the just war doctrine presumes such legitimate use of force if it is to preserve peace. It also establishes ethical boundaries on the waging of war, which presents two fundamental questions: when is it morally and legally justified to go to war? And what moral precepts are to be followed during war?

Just War Doctrine

The just war doctrine is concerned with the ethical justifications for military action, and the forms that warfare may or may not take, as well as a historical body of rules or agreements that have been enforced in various military campaigns.

Marcus Tullius Cicero was the first to use the expression bellum iustum (just war).3 In his Republic (54–51 BC), he affirmed that a state had the right to use military action on a group of people who were not capable of exercising justice.4 The natural state of man, according to the great Orator, was that of peace, for which war was an unnatural breach. Hence, he argued: ‘Wars, then, are to be waged in order to render it possible to live in peace without injury’,5 i.e. they should advance some good beyond merely self-interested expansion. In other words, the principle of self-defence against physical aggression would putatively be the only acceptable basis for a war, though it can also be extrapolated to anticipate probable hostile acts of aggression.

It was, however, Saint Augustine of Hippo (354–430) who, influenced by Cicero, developed the just war philosophy into the doctrine familiar to us today.6 The Augustinian position is based on a naturalistic morality, i.e. the natural law written in the heart of God’s sentient creatures.7 By nature, Augustine holds, no one has the right of dominion over another human being, and therefore a war can be fought ‘only to prevent or to punish the unjust actions of the aggressor’.8 Since the object is peace, he explains: ‘[W]ar should be waged only as a necessity, and waged only that God may by it deliver men from the necessity and preserve them in peace. For peace is not sought in order to the kindling of war, but war is waged in order that peace may be obtained.’9 Once a war has begun, it must be fought in a manner which:

  • represents a proportional response to the wrong to be avenged, with violence being constrained within the limits of military necessity;
  • discriminates between proper objects of violence (that is, combatants) and non-combatants, such as women, children, the elderly, the clergy, and so forth;
  • observes good faith in its interactions with the enemy, by scrupulously observing treaties and not prosecuting the war in a treacherous manner.10

The ‘Justification’ of War in the Old Testament?

Many Christians, specifically those who identify themselves as fundamentalists, appeal to the Old Testament to legitimize not only ‘just’ wars, but offensive measures for territorial expansion. They refer, for example, to the Books of Deuteronomy and of Joshua in which the God of the Israelites ordered Joshua to wipe out the Canaanites, Jebusites, and others:

  • ‘Only in the cities of these peoples that the Lord your God is giving you as an inheritance, you shall not leave alive anything that breathes. But you shall utterly destroy them: the Hittite and the Amorite, the Canaanite and the Perizzite, the Hivite and the Jebusite, as the Lord your God has commanded you, so that they may not teach you to do according to all their detestable things which they have done for their gods, so that you would sin against the Lord your God.’ (Deuteronomy 20, 16–18)
  • ‘When Joshua and the men of Israel had finished slaying them with a very great slaughter, until they were wiped out, and when the remnant which remained of them had entered into the fortified cities, all the people returned safe to Joshua in the camp at Makkedah; not a man moved his tongue against any of the sons of Israel.’ (Joshua 10, 20–21)

Such military campaigns, as with David’s war with the Amalekites (1 Samuel 30) or with the Philistines (2 Samuel 5, 17–25), were not just wars but ‘holy wars’ in order to highlight the socio-political role of God’s chosen people over others. They can allegorically be understood within a story that reveals a God who is determined to eliminate sin and renew his creation, notwithstanding revulsion towards military conquest.

‘Cicero […] affirmed that a state had the right to use military action on a group of people who were not capable of exercising justice’

A note to the reader: I as a Christian, more so as a Roman Catholic priest, find it challenging to reconcile the God who smites innocent people11 and commands war in the Old Testament with the merciful God revealed in the Gospels, such as when Jesus Christ forgave the adulteress who, according to the Mosaic law, should have been stoned to death.12 Yet the purpose of this section is to distinguish a ‘just war’ from a ‘holy war’, not a moral exegesis of the latter.

The Flaw in Pacifism

Pacifists argue that even for defensive purposes a ‘just war’ is inherently immoral, while others suggest that there is no place for ethics in war. Conscientious objectors, like Jehovah’s Witnesses and certain Catholics and Protestants, maintain the incompatibility of the use of force with biblical passages, such as:

  • ‘Thou shall not kill.’ (Exodus 20, 13);
  • ‘Do not resist evil, if someone strike you on the right cheek turn to him the left also.’ (Matthew 5, 39);
  • and ‘He who lives by the sword, dies by the sword.’ (Matthew 26, 52)

Naturally, peaceful resistance is ideal, but it could also be destructive since it has historically been proven, at times, to facilitate an aggressor’s objectives, as it did with the National Socialists prior to the Second World War.

The Commandment ‘Thou Shalt not Kill’ is God’s proscription to not single out any innocent life and terminate it, as in the case of abortion or euthanasia. Simultaneously, as taught by the Catechism of the Catholic Church: ‘The legitimate defence of persons and societies is not an exception to the prohibition against the murder of the innocent that constitutes intentional killing. The act of self-defence can have a double effect: the preservation of one’s own life; and the killing of the aggressor. […] The one is intended, the other is not.’13

Arnold Böcklin, The War (1896). Galerie Neue Meister, Dresden, Germany. PHOTO: Wikipedia

Pacifists, nonetheless, refer to what Saint Thomas Aquinas (1225–1274) said in his Summa Theologiae, II, IIae, Q. 40 (Of War), article 1: ‘Whether It Is Always Sinful to Wage War?’ They say that the title in itself expresses a clear prohibition against the use of force, i.e. by ‘starting with the idea that war might be sinful, Aquinas seems to establish a burden of proof in favour of nonviolence and against war’.14

The Angelic Doctor, while highlighting peace, rejected the principle of non-resistance (‘turn the other cheek’). He explained that it was not God’s intention to prohibit resistance to evil when it is carried out for love of the public good. The evangelical command was rather to halt the act of revenge on behalf of one’s violated private good.15 He further says: ‘[T]o have recourse to the sword (as a private person) by the authority of the sovereign or judge, or (as a public person), [is not] to arm oneself in order to take the life of anyone [i.e. commit murder] […] but to use it as commissioned by another, wherefore it does not deserve punishment.’16 Yet for a war to be just, and here he parallels St Augustine, three things are necessary:

  • The authority of the sovereign by whose command the war is to be waged.
  • A just cause, namely that those who are attacked (the aggressors), should be attacked because they deserve it on account of some fault.
  • A rightful intention on the part of the combatants, so that they intend the advancement of good, or the avoidance of evil.

At the same time, while civilians may not be targeted in war, all combatants, on the other hand, are morally permitted to target one another, even when doing so can foreseeably harm some civilians. A question thus arises regarding the legitimacy of a state entering a war in order to aid another country under attack. The first to tackle this was the Spanish Dominican Friar Francisco de Vitoria (1483–1546).

International Intervention

In his Reflectiones Theologicae, discovered after the First World War,17 which is still discussed in today’s multicultural age of military intervention to protect human rights, Vitoria sought to address the conflicts of his time by applying natural law. These conflicts included the spread of Protestantism, the continuous wars between the French and Habsburg monarchs (complicated by the Ottoman Turkish threat), and the Spanish campaigns of colonial conquest in the Americas.

For Vitoria, the principle of ‘responsibility to protect’ was the foundation of every action taken by those in government with regard to the governed. At a time when the concept of national sovereign states was first developing, the Dominican friar described this duty as one aspect of natural reason shared by all nations.

Vitoria’s concept was also critical of the idea of conquest by divine right. He was fully convinced on scriptural evidence, as he wrote his most notable work, De Indis (On the American Indians, 1532), that the European states’ claim to universal jurisdiction could not be qualified as a de facto or de iure reality.18

In like manner, he refuted the argument that war could be waged on a group of people just because they were pagans or refused to accept Christianity—for religious belief was an act of the will and could not be forced. Nor could they be castigated for their offences against God, especially since Christians themselves committed just as many such misdeeds as pagans. Vitoria did, however, justify conquest in order to protect innocent life from cannibalism and human sacrifices that were committed on large scale by the indigenous peoples of the New World, as in the case of the Aztecs.19


US President Woodrow Wilson, after a policy of neutrality at the outbreak of the First World War, led America, with Congressional approval, into war in order to ‘make the world safe for democracy’. As during the conflict with the Axis Powers, there are times when the use of force must be carried out if innocent life is to be safeguarded. This is not just a right, but a duty, even if it results in the deaths of those fighting for peace.

The inherent dilemma regarding the rules of engagement in a just war is that they tend to become either vague or restrictive when military operations fail to achieve victory or a ceasefire leading to peace. Consequentialism then becomes the decisive factor when it is thought that more will be gained than lost from breaking the rules, and then there are no limits to the brutality.

The most salient example in modern time occurred when the United States dropped atomic bombs over the cities of Hiroshima and Nagasaki—it brought the war in the Pacific to an immediate halt. Nevertheless, as G. K. Chesterton is quoted in saying, ‘The true soldier fights not because he hates what is in front of him, but because he loves what is behind him.’20


1 Thomas Paine, Quotes about War, 2, www.azquotes. com/author/11249-Thomas_Paine/tag/war?page=2, accessed 3 December 2022.

2 Paine, Quotes from Famous People, https://quotepark. com/quotes/1787741-thomas-paine-we-fight-not-to-enslave-but-to-set-a-country-free/, accessed 3 December 2022.

3 Andrea Keller, ‘Cicero: Just War in Classical Antiquity’, in From Just War to Modern Peace Ethics,, accessed 4 December 2022.

4 ‘Cicero’s Just War Theory Analysis’, in IPL,, accessed 4 December 2022.

5 Marcus Tullius Cicero, De Officiis, ed. John Woo, in Hoover Institute,, accessed 3 December 2022.

6 Cf. Berit Van Neste, ‘Cicero and St. Augustine’s Just War Theory: Classical Influences on a Christian Idea’, Scholar Commons, 7–11, https://digitalcommons.usf. edu/cgi/viewcontent.cgi?article=4978&context=etd, accessed 4 December 2022.

7 Mario Alexis Portella, ‘The Value of Reviving the Natural Law’, Hungarian Conservative (28 November 2021),, accessed 4 December 2022.

8 Herbert A. Deane, The Political and Social Ideas of Saint Augustine (New York: Columbia University Press, 1966), 158–159.

9 St. Augustine of Hippo, ‘Letter 189’, in New Advent,, accessed 4 December 2022.

10 St. Augustine, ‘Jus ad Bellum and Jus in Bello’, in Internet Encyclopaedia of Philosophy,, accessed 4 December 2022.

11 ‘When the Lord goes through the land to strike down the Egyptians, he will see the blood on the top and sides of the doorframe and will pass over that doorway, and he will not permit the destroyer to enter your houses and strike you down. […] At midnight the Lord struck down all the firstborn in Egypt, from the firstborn of Pharaoh, who sat on the throne, to the firstborn of the prisoner, who was in the dungeon, and the firstborn of all the livestock as well.’ (Exodus 12, 23 and 29)

12 Cf. Gospel of John 8, 1–11.

13 Catechism of the Catholic Church, 2nd ed., n. 2263–67 (Vatican City: Liberia Editrice Vaticana, 1997), 545–546.

14 Richard B. Miller, ‘Aquinas and the Presumption against Killing and War’, The Journal of Religion, 82/2 (April 2002), 181,, accessed 3 December 2022.

15 Gregory M. Reichberg, ‘Thomas Aquinas between Just War and Pacifism’, The Journal of Religious Ethics, 38/2 (June 2010), 229–230.

16 St. Thomas Aquinas, ‘Of Contention’, in Summa Theologiae, II, IIae, Q. 40, a.1 (New York: Benzinger Brothers, Inc., 1947), 1360.

17 Cf. Francisco Vitoria, De Indis and De Jure Belli, ed., J. B. Scott (Washington, DC: Carnegie Institute of Washington, 1917), Preface; Inderjeet Paramar, Foundations of the American Century: The Ford, Carnegie, and Rockefeller Foundations in the Rise of American Power (New York: Columbia University Press, 2012, 2), 68–96.

18 Cf. Adrien Jahier, ‘Francisco de Vitoria and on the American Indians: A Modern Contribution to International Relations’, E-International Relations (24 September 2009),, accessed 4 December 2022.

19 Lizzie Wade, ‘Feeding the Gods: Hundreds of Skulls Reveal Massive Scale of Human Sacrifice in Aztec Capital’, Science, human-sacrifice-aztec-capital, accessed 4 December 2022.

20 ‘War and Politics’, Society of G. K. Chesterton,, accessed 4 December 2022.

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The inherent dilemma regarding the rules of engagement in a just war is that they tend to become either vague or restrictive when military operations fail to achieve victory or a ceasefire leading to peace.