Lawful means in war

In a just war all means that conduce to the end of gaining victory over the enemy are lawful, provided that they are not against the law of nature and international law or agreement. International agreements are only binding if they are faithfully adhered to by the adverse party. In modern war it is the practice to spare the persons and property of non-belligerents as far as possible. In naval warfare not only the enemy’s ships of war may be attacked and taken, but his merchantmen, and any British vessel or vessel of an ally trading with or acting in the service of the enemy at war with England, or any neutral vessel engaged in the same way or in the carriage of contraband, and blockade runners, may be captured and made lawful prize by duly commissioned British ships. war on land is restricted to arms, ammunition, Booty of and military provisions and stores. Private property on land is no longer liable to capture and confiscation, but requisitions and contributions of men for labour, money, victuals, etc., are still levied on the invaded territory by duly qualified officials of the invading army. Beyond these limits, or at least beyond what is permitted by lawful authority, it is not allowed to appropriate private property belonging to the enemy.

What is lawful to do against the enemy in war? - In a just war it is lawful to do all things against the enemy which are necessary and apt for obtaining the just end of war, yet according to the command and express or tacit will of the commander of the war. The reason is that he who has a right to the end also has a right to the necessary and apt means. Therefore in a just war it is lawful to do against the enemy all things which are necessary and apt for obtaining the just end of war. Which are necessary and apt; for other things harmful to the neighbor, which are not necessary for such an end, cannot justly be inflicted, and the damage afterward must be repaired. The just end of war, namely to overcome the enemies. Laym. 9; Sporer 112; Struggl 45; L. 409.

You will resolve: In a just war it is lawful to fight in open warfare, and to use ambushes and stratagems. These are not reputed lies, because the adversaries are deceived by their own fault, since those means are customarily used in war. But deceits are unlawful which cannot be guarded against by prudence. It is lawful to deprive cities of water; but it is not lawful to infect wells and fountains with poison, or otherwise to use methods of bringing slaughter which can be avoided by no human prudence, or which bring grave harm even to the innocent, or which savor of cruelty and atrocity, S. Th. 2. 2, q. 108, a. 2 ad 3; much less indeed is it lawful directly to kill the innocent, legates, cf. 737, who by the law of nations are everywhere inviolable, and likewise to suborn assassins who secretly butcher the Prince or commander of the army.

Therefore the use of any kind of weapons is lawful, provided that these are not poisoned, or lethal in another similar way. It is lawful to besiege cities and citadels, to discharge artillery against them, indeed sometimes to destroy or burn monasteries and churches, to plunder and kill in them, if, for example, enemies use a church as a citadel for defending themselves.

To use the standards of enemies in order to deceive enemies is a very true lie of fact.

Scouts also, who are sent to enemies under the appearance of friends or by another fictitious reason, and approach them asking, for example, medicines which they do not need, are not even free from a lie.

Lying, deceit, fraud are never lawful. Likewise it is sometimes lawful to give a captured city to plunder, but only for most grave reasons. This, however, is not lawful for soldiers by their own authority, but it is necessary that legitimate permission be present. And then it is in no way lawful directly to kill the innocent, under whose name come children, women, the elderly, foreigners, clerics, peasants, merchants, etc., because these have committed nothing on account of which they could be deprived of life, nor are they actual or proximate aggressors. Moreover it is not lawful per se to despoil innocent foreigners even of goods, because they are guilty neither in themselves nor in society. Likewise, when a city is given to plunder, monasteries, churches, and pious places are always excepted. C. 2 de Treg. et pac. But immovable goods by the law of war fall to the Prince or commonwealth; movable goods of use become the property of the first taker, unless custom or law is that a part fall to the Prince and community, or all be placed in common, and distribution be made to individuals with due proportion. Besides spoils, reprisals also are lawful; they are occupation by force made and retention of persons or things of enemies, which by chance or by design come into the hands of the other party, since they are certain compensations and a kind of war. They are lawful, if however: 1. It is manifestly established that citizens of the other commonwealth have done an injury. 2. If their superiors, when asked, refuse to administer justice. 3. If it is established that they culpably refuse this. 4. If the supreme Prince, the cause having been known, concedes this. 5. If no more damage is inflicted than just satisfaction requires. 6. If they are not committed against ecclesiastical persons; C. Etsi unic., de Iniur. in 6. In the conflict itself or attack it is lawful to kill all fighting against one, or existing in arms, of whatever condition, state, or sex, until they give themselves as captives, and perfect victory is obtained. But after the conflict and victory obtained, it is sometimes lawful also to kill captured or surrendered guilty persons, namely if before this they have merited death by some crime; or if this is necessary for establishing peace and security or justly vindicating the injury, unless they have surrendered with a pact of life to be preserved; or unless they are clerics, even guilty, whom after the conflict it is in no way lawful for a secular Prince to kill because of their immunity. But since soldiers today are regularly compelled and not voluntary, they also are to be held as innocent, whom it is not lawful to kill after conflict. 1 Kings 30; C. Miles 13, c. 23, q. 5; L. 409, 410; Struggl 47 seqq.; Ithur. Cas. 40, nn. 14, 17; Laym. l. 2, tr. 3, c. 12, nn. 7, 9 seqq.; S. Th. 2. 2, q. 40, a. 3; q. 66, a. 8 ad 1; q. 108, a. 1 ad 5.

Can Catholic Princes in war call heretics or even gentiles to their aid? - The first opinion universally affirms. The second opinion absolutely denies. The third opinion affirms that per se it is lawful; nevertheless per accidens by reason of scandal and harm to religion, which for the most part is present, it is unlawful. "This third opinion," says St. Alphonsus 406, "speculatively is indeed probable, but the second in practice seems altogether to be held. The reason is that it is morally impossible that, with alliance contracted with enemies of the faith, the aforesaid harms will not come to religion." Prop. 62 Syll. condemned by Pius IX; E. M.

When war has been completed, are the parties bound to preserve public pacts, extorted by the force of war and of victory obtained? Gury, Cas. 410, responds affirmatively to this question. "The reason is," he says, "because public treaties were introduced by the law of nations, common to the whole human race, the common good of the human race so requiring.

For unless public pacts between so many different Princes, and between magistrates and subjects, were to be preserved in every way, no stable peace or society could consist; but a way would be opened to perpetual wars and slaughters." Reuter has the same opinion, which he affirms to be common, saying p. 3, n. 510: "Public faith given to an enemy, even one waging an unjust war, is to be preserved, provided the treaty is not objectively evil." Concerning this same question Lugo has these things: "In war, because of the public good of peace and the security of kingdoms, it is necessary that pacts be preserved on both sides, when they are made without coercion and fear; otherwise, since each one presumes that he has a just cause of war, pacts of this sort would never be preserved, which would be the greatest impediment to composing peace; just as also, because of the same reason, impunity and indemnity are owed to orators and public legates, because otherwise there could not be negotiation concerning peace, which would be a great inconvenience." De Iust. et Iur. d. 37, s. 15, n. 179. And S. Th. 2. 2, q. 40, a. 3 says: "Someone can be deceived from the deed or saying of another from the fact that something false is said to him or a promise is not kept; and that is always unlawful; and in this way no one ought to deceive enemies; for there are certain laws of wars, and treaties to be preserved even among enemies themselves." C. Noli 3, c. 23, q. 1. Laym. l. c. nn. 15, 16.

353. What is licit or illicit in time of war can be defined only with difficulty; some things are determined by natural law, some by the law of nations; and since customs are diverse according to times and places, certain things today among cultivated nations are held as illicit which formerly were esteemed as legitimate. Hence in practice the modern expositors of international law must be approached, who declare at length what is licit, with attention paid to the customs, conventions, and laws of various nations.¹ We hand down only certain more general things briefly.

¹ Cf. H. Bonfils, op. cit., p. 571-877. - Hence not a few of the things which are set forth by older theologians on this matter, with circumstances changed, must be reformed today.

354. (A) Today, among cultivated nations, the declaration of war ought to be preceded by what they call an ultimatum, that is, an intimation concerning war soon to be undertaken, unless such or such a condition be fulfilled; for thus a last opportunity is given to the enemy of repairing the injury inflicted. - Moreover at the time when war is declared, humanity demands that to foreigners living within the borders of the territory some space of time be granted, within which they can provide for themselves and their goods.

355. (B) Once military operations have begun, it must be kept before the mind that war is not waged against private citizens, but against the nation as a public person. (a) Hence, although all things are licit which are necessary for breaking the forces of the enemies, it is held today as illicit to usurp the goods of private persons without compensation,¹ and a fortiori directly to kill noncombatants or reduce them into captivity.² But since the expenses of war can be exacted from the enemy, the victor, when cities and villages have been captured, can impose taxes, provided they are proportionate to the resources of the inhabitants;³ but to give a captured city to the army for plunder is not licit today.⁴

¹ H. Bonfils, op. cit., p. 664-682.

² Ibid., p. 638-643.

³ Ibid., p. 674-677.

⁴ Ibid., p. 678-680.

356. (b) It is licit to besiege fortified citadels, and to deprive them of water and food, so that they may submit themselves more quickly; likewise to discharge artillery (canons) against them, even with the danger of killing innocents; to demolish houses, even monasteries and churches, when the enemies use them to protect themselves; likewise to destroy the walls of a city, etc.; because all these things are necessary for conquering the enemies. - But it is illicit to infect springs or wells with poison, or to use poisoned weapons, because these things, as cruel, are prohibited by the modern law of nations.

357. (c) Whether reprisals are licit, that is, actions otherwise prohibited by international law, when the enemies first have violated the law of nations, is not so certain. If they are employed only for this end, that the enemies may thus be compelled to avoid injuries of this kind, strictly speaking they are not unjust, because they are one of the means of averting similar injuries in the future. But since in this matter it is easy to exceed, and on the other hand this mode of acting can induce the enemy to inflict new and worse injuries, generally it is expedient to abstain from this, while nevertheless protesting against an open violation of international law.⁵

⁵ Ibid., p. 575-579.

(d) To prepare ambushes for enemies, and to use various stratagems for overcoming them, is part of military prudence, and is prohibited by no law; likewise it is licit to search out the secrets of the enemies and, when these are known, to use them for conquering the same more easily; for all these things are very useful for pursuing the end of war.

358. (C) When war has been ended and the enemy asks for peace, the victor ought to use the victory obtained moderately. For he can:

(a) Exact that for which war had been declared, e.g., recovery of a province, satisfaction for grave injury inflicted, etc.; for since the war is supposed just, it certainly gives the power of vindicating rights which he already possessed beforehand; (b) demand an equitable indemnity for the expenses of war and other damages inflicted on the occasion of the war; for all these things are deservedly imputed to the enemy who unjustly undertook war; (c) exact securities for future safety; for the victor ought wisely to provide for his own security; e.g., the conquered nation can be bound to hand over fortified places situated on the borders into the hands of the victor, at least for a time, or to demolish them and not build new ones, - but not to cede to the victor all provinces and cities captured during the war; yet certain parts of the occupied region could be retained by way of indemnity, if the conquered could not pay money.¹

¹ H. Bonfils, op. cit., p. 874-877.

47. Preliminary Note. Since this booty to be taken pertains to well-known owners, it is acquired by occupation not properly but broadly so called. For occupation properly so called is concerned with things belonging to no one, as was said above. Nevertheless old Roman law considered the goods of enemies as things belonging to no one, which therefore could be acquired by true and properly so-called occupation. Hence it established: "Things captured in war ... become his who first obtained possession of them."²⁷ Canon law indeed adopted this doctrine, but limited it to a just war.²⁸

Just as customs have changed with regard to hunting, so similarly in present times, with regard to booty during war, much milder usages prevail than in ancient times. Hence also on this point the authority of the old doctors is not to be exaggerated. In ancient times the saying was held as an adage: "The right of war is unlimited"; and St. Thomas²⁹ wrote: "Concerning booty one must distinguish; because, if those who despoil enemies have a just war, the things which they acquire by violence in war become theirs; and this does not have the character of robbery, whence they are not held to restitution." But now, through international agreements, the right of plundering in time of war has been determined in many things (although not in all).³⁰

General Principles Of Present International Law:

1. All those things can be seized from the goods of the enemy which are necessary for waging a just war, for example weapons, food, clothing. Such exactions today are customarily called "contributions" and "requisitions."

2. Booty taken does not pertain to individual soldiers, but to the belligerent government, according to that saying: "Things acquired in war fall to the republic."

3. Outside the case of true need, individual soldiers cannot licitly take from enemies, by their own authority, either food to eat or clothing to wear.

4. Since war is not waged against individual citizens and private persons, but against the whole kingdom, the goods of private persons are inviolable, unless, however, there is urgent necessity, or those private persons illicitly attack the soldiers. Thus at least in land war; for in naval war international statutes concerning this matter have not yet been accepted by all nations.

Corollaries. 1. Soldiers who, laboring under hunger, seize food from enemies without the authority of a superior officer act illicitly indeed, but they are not obliged to restitution, because the prohibition is made rather for preventing abuses and for preserving military discipline than for establishing an obligation of justice. 2. Soldiers seizing other goods of notable value from enemies without legitimate authority are held under grave obligation to restitution, not indeed from natural law, but from international agreements; and if in some war these are not observed on both sides of the belligerents, they can no longer effect that those soldiers ought under grave obligation to restore.³¹

²⁷ L. 1, D. 41, 2.

²⁸ Cf. Ferraris, Prompta bibliotheca, s. v. bellum, art. 3.

²⁹ S. theol. 2, 2, q. 66, a. 8 ad 1.

³⁰ Among the international agreements made concerning this matter those stand out which were entered at The Hague of the Dutch on 29 July 1899 and 18 Oct. 1907. Other agreements for naval war also were made at London on 26 Feb. 1909.

³¹ We wrote more broadly concerning this matter of great moment in Linzer Theol. Quartalschrift 1918.

274. Principle II. For waging war justly and licitly, even a just war, both the natural law and the prevailing statutes of the law of nations and international agreements must be observed. — For evils must not be done that goods may come. Hence a) in a just war all things are licit which are necessary or apt for obtaining the end and are permitted by right: for he who has a right to the end has a right to the means. On the contrary b) those things which are forbidden or useless cannot be employed without injustice, and therefore damage thus inflicted must be repaired. — But by present-day right:

A. The principle holds: War is not waged against private citizens, but against the nation as a public person.

Hence 1) it is licit to besiege fortified strongholds and deprive them of water or food so that they surrender more quickly; to fire artillery against them even with the danger of indirectly killing the innocent; to destroy private houses, monasteries, churches when enemies use them for defending themselves; to destroy the walls of a city, etc., insofar as these things are necessary or useful for conquering the enemies and done with the permission of the commander; — but not to infect springs or wells with poison, or to use poisoned weapons, because these things are cruel and not necessary: namely, the manner of waging war must be humane, withdrawing from all savagery and ferocity;

2. it is licit to render harmless by armed force those fighting and existing under arms, and for this to wound them, indeed, if it is necessary, directly to kill them; not however enemies already captured (unless by sentence of a judge they were proved guilty of a more grave crime); — a fortiori it is illicit directly to kill or reduce to captivity ambassadors, or hostages (even if they consented to death, because they are not masters of their own life), or innocents, such as children, women, old men, clerics, religious, merchants, etc., who are presumed to be not armed and contributing nothing to the war, or pilgrims or foreigners;

3. it is licit, on account of the expenses of war, to impose upon captured cities or regions taxes proportionate to the resources of the inhabitants, and to require from them things necessary for sustaining the army; — not however, by received right, to hand over a captured city to the army as prey, or in land war to usurp the goods of private persons without necessity or equitable compensation; the contrary holds in naval war; a fortiori it is altogether illicit to despoil or take the goods of guests, foreigners, or the Church;

4. it is licit to set ambushes for enemies and to use stratagems to overcome them, for example, simulated flight, feigned aggression, deceptive signs, the obtaining of intelligence, etc.; — but betrayals, violations of treaties or even of a true promise, or frauds which can be guarded against by no prudence, are not licit, such as infecting springs with poison, suborning assassins who secretly slaughter, etc.;

5. reprisals are dangerous and easily provide occasion for more grave evils; — nevertheless they can be licit, but exclusively by command of the prince, where the injustice inflicted is established, satisfaction cannot be had otherwise, and they are exercised against guilty persons or against goods, and just compensation is not exceeded.

B. War is not to be begun before a formal declaration of war is made, which ought to be preceded by an ultimate warning, that is, an intimation concerning war about to be undertaken immediately unless such and such a due condition is fulfilled.

Thus a final opportunity is given to the enemy of repairing the injury inflicted, and, to foreigners staying within the borders of the territory, time within which they can provide for themselves and their goods.

C. When the enemy has been conquered and asks for peace, equitable and moderate conditions are to be established, without harshness or a spirit of harming. For, as Fr. de Victoria notes,⁵ the victor ought to pronounce concerning the conditions of peace, not indeed as victor or as accuser or enemy, but as an equitable judge and according to the rights and merits of the cause; and to dictate those conditions by which international order may be restored, namely the order of justice and cooperation, so that good relations between the victor and the conquered may again be possible. Therefore it is unjust to impose harsh or excessively burdensome conditions, or to bring on the ruin or destruction of the adverse nation.

⁵ Cited work, at the end.

Nevertheless these can be demanded in a just war: just satisfaction of the right on account of which the war was declared; — indemnities for necessary expenses of war and damages, but proportioned to the means and resources of the conquered; — also moderate precautions for security, if it is necessary.

Treaties of peace, since they have been entered upon for the common good of nations, must be altogether observed, unless they are certainly proved to labor under most manifest injustice; and this is not easy.

You will ask 4° whether in a just war it is licit to kill innocents.

I answer. In a just war it is never licit per se and by intention to kill innocents, unless special authority has been made by God. Yet it is licit per accidens and beside intention. Proof of the first part. 1° From that general command of God, Exod., XXIII, 7: Thou shalt not kill the innocent and just. 2° An innocent cannot be killed in a just war except on account of the guilt of the state. But that is not licit. Ergo. — Proof of the minor. The state cannot be punished by the enemy except in goods over which it has dominion. But the state has not dominion over the life of innocents, but God alone, who granted not the right of the sword to the state except against those who do evil. Ergo.

Under the name of innocents come infants, children unfit for war, women, peasants, plebeians, merchants having nothing to do with war, clerics and religious, cap. de treuga et pace, lib. I Decretal., tit. 34, c. 2. All these, I say, by presumption of law are judged innocent, until the contrary be proved of them.

Proof of the second part: 1° If neither per accidens and beside intention killing innocents were licit in a just war, it would be impossible to carry out a war : a city could not, e.g., be stormed, or a tower demolished in which innocents were enclosed; enemies could not be attacked who placed innocents in the front of battle, which they would never omit, and thus the justice of the combatants would be frustrated. 2° When two effects, equally immediate, of one act, the one good, the other evil, can, a just reason subsisting, the good effect be intended and the evil permitted.²¹⁹ But the demolition of a tower or the explosion of war machines upon enemies is immediately protective of the homeland and destructive of innocents. Ergo the first effect can be intended for the common good, and the other permitted. This principle of the Author more widely drawn out and expounded you have dissert. VIII, On Justice, art. 2. ²¹⁹ Here q. 64, a. 7, o.

You will ask 5° what are the obligations and sins of combatants.

I answer. 1°. Supreme princes and leaders of armies 1° are bound ex officio to see that military discipline be observed insofar as they can, and to coerce soldiers from plunderings, thefts, burnings, ravishments, etc.; otherwise they sin mortally and are bound to restitution of those damages. 2° They sin mortally if they provide not just pay to the soldiers, and they are bound to restitute damages which soldiers inflict by lack of pay.

I answer. 2°. Subordinate leaders sin mortally and are bound to restitution : 1° If, no necessity compelling, they rashly expose soldiers to sure slaughter. 2° If they retain part of the pay or moneys conceded for soldiers. 3° If they have a smaller number of soldiers and receive pay for a greater, such are those who, while the troops are mustered, present not real soldiers in military dress, commonly called passe-volants, or present the same twice or thrice : into which sin also those muster-masters or commissaries implicate themselves who knowingly admit it; nor are they bound only for theft of pay, but for the damage which can accrue to the state on account of insufficient number of soldiers. Except how, they shall have seen. 4° Those sin and are bound to restitution who, while they lead troops through a province, on account of accepted gifts from certain villages or citizens, burden other villages, or citizens, with the number of soldiers.

I answer. 3°. Common soldiers 1° ought to be content with their pay, according to the precept of the holy Precursor, Luc., III, 14. Whence they sin mortally and are bound to restitution if, in lands not hostile, beyond roof, bed, straw, etc., as custom allows, they extort moneys, despoil, pillage, or otherwise do damage. Nor does the authority or connivance of leaders excuse them, unless perchance, the pay failing or diminished, they take precisely what is necessary for urgent need. 2° They are bound, even with certain peril of life, not to desert their post, or fortress, unless victory be plainly despaired of.

[I answer. 4°. While war lasts, all those things are licit which are permitted by the law of nations and are necessary for obtaining the end. Hence it is licit to prepare ambushes, employ stratagems, e.g., feign flight, etc. In a just war it is licit to besiege cities and storm them, deprive them of water. Likewise to despoil innocents of goods, if they be members of the enemy state, nor can victory be had otherwise. It is licit even to demolish churches, if enemies use them for defense. Sometimes, but only from the most urgent cause, cities can be delivered to plunder. This however is adverse to modern customs, besides the case where a justly imposed tribute is denied.

But illicit are frauds which can be guarded against by no prudence, as to infect wells and fountains with poison. Nor is it licit to hire assassins who secretly slay the leader of the opposing army; for, by consent of all, perfidy can never be made honorable.

Likewise it is not licit to kill captives taken in war and all who can harm no longer, except in punishment of crime. Captives moreover can flee, if no promise given by them stand in the way.^{220 220} Cfr. Marci, Institut. morales Alphonsianae, n. 751.

264. The manner of waging war should be conformable to the approved usages of civilized nations. To be effective, it necessitates destruction of life and property, confiscations, sieges, blockades, battles, bombardments, and all the horrors unavoidably connected with such measures. But it does not justify:

1. Any useless or wanton violence or destruction by which the final settlement is not furthered; for instance, the direct killing or ill-treating of non-combatants, such as women and children.

2. The killing of prisoners or wounded soldiers who have no more power to injure.

3. The use of means universally execrated as unnecessarily cruel, such as envenomed weapons, poisoned wells, etc.

4. The use of means that are in themselves unjust, such as lying, perjury, and solicitations to treason.

5. The continuation of hostilities when a settlement has been made possible.

265. The victorious nation has the right:

1. To possess the object for which the war was waged, and to which it had all along a just claim.

2. To exact compensation for the damages sustained in the war.

3. To provide for its future security against a dangerous foe. This may even necessitate the permanent subjection of the defeated nation. Moderation, justice, and humanity must ever prevail.