The Law of Nations or the Principles of Natural Law (1758)

Emmerich de Vattel

Of the Instruments of War: the Raising of Troops, Etc.; Their Commanders, or the Subordinate Powers in War

§ 6. Instruments of war.1
THE sovereign is the real author of war, which is carried on in his name, and by his order. The troops, officers, soldiers, and, in general, all those by whose agency the sovereign makes war, are only instruments in his hands. They execute his will and not their own. The arms, and all the apparatus of things used in war, are instruments of an inferior order. For the decision of questions that will occur in the sequel, it is of importance to determine precisely what are the things which belong to war. Without entering here into a minute detail, we shall only observe that whatever is peculiarly used in waging war, is to be classed among the instruments of war; and things which are equally used at all times, such as provisions, belong to peace, unless it be in certain particular junctures, when those things appear to be specially destined for the support of war. Arms of all kinds, artillery, gun-powder, salt-petre and sulphur of which it is composed, ladders, gabions, tools and all other implements for sieges, materials for building ships of war, tents, soldiers’ clothes, etc.: these always belong to war.

§ 7. Right of levying troops.2
As war cannot be carried on without soldiers, it is evident that whoever has the right of making war, has also naturally that of raising troops. The latter, therefore, belongs likewise to the sovereign (§ 4), and is one of the prerogatives of majesty (Book I. § 45). The power of levying troops, or raising an army, is of too great consequence in a state, to be intrusted to any other than the sovereign. The subordinate authorities are not invested with it; they exercise it only by order or commission from the sovereign. But it is not always necessary that they should have an express order for the purpose. On those urgent exigencies which do not allow time to wait for the supreme order, the governor of a province, or the commandant of a town, may raise troops for the defense of the town or province committed to their care: and this they do by virtue of the power tacitly given them by their commission in cases of this nature.

I say that this important power is the appendage of sovereignty; it makes a part of the supreme authority. But we have already seen that those rights which together constitute the sovereign power, may be divided (Book I. §§ 31, 45), if such be the will of the nation. It may then happen that a nation does not intrust her chief with a right so dangerous to her liberty as that of raising and supporting troops, or at least that she limits the exercise of it, by making it depend on the consent of her representatives. The king of England, who has the right of making war, has also, indeed that of granting commissions for raising troops; but he cannot compel any person to enlist, nor, without the concurrence of parliament, keep an army on foot.3

§ 8. Obligation of the citizens or subjects.3
Every citizen is bound to serve and defend the state as far as he is capable.3 Society cannot otherwise be maintained; and this concurrence for the common defense is one of the principal objects of every political association. Every man capable of carrying arms should take them up at the first order of him who has the power of making war.

§ 9. Enlisting or raising of troops.
In former times, and especially in small states, immediately on a declaration of war, every man became a soldier; the whole community took up arms, and engaged in the war. Soon after, a choice was made, and armies were formed of picked men, — the remainder of the people pursuing their usual occupations. At present, the use of regular troops is almost everywhere adopted, especially in powerful states. The public authority raises soldiers, distributes them into different bodies under the command of generals and other officers, and keeps them on foot as long as it thinks necessary. As every citizen or subject is bound to serve the state, the sovereign has a right to enlist whom he pleases. But he ought to choose such only as are fit for the occupation of war; and it is highly proper that he should, as far as possible, confine his choice to volunteers who enlist without compulsion.

§ 10. Whether there be any exemptions from carrying arms.
No person is naturally exempt from taking up arms in defense of the state, — the obligation of every member of society being the same. Those alone are excepted, who are incapable of handling arms, or supporting the fatigues of war. This is the reason why old men, children, and women are exempted. Although there be some women who are equal to men in strength and courage, such instances are not usual; and rules must necessarily be general, and derived from the ordinary course of things. Besides, women are necessary for other services in society; and, in short, the mixture of both sexes in armies would be attended with too many inconveniences.

A good government should, as far as possible, so employ all the citizens, and distribute posts and employments in such manner, that the state may be most effectually served in all its affairs. Therefore, when not urged by necessity, it should exempt from military service all those who are employed in stations useful or necessary to society. Upon this ground, magistrates are usually exempted, — their whole time not being too much for the administration of justice and the maintenance of order.

The clergy cannot naturally, and, as matter of right, arrogate to themselves any peculiar exemption. To defend one’s country is an action not unworthy of the most sacred hands. That article of the canon law which forbids ecclesiastics to shed blood, is a convenient device to exempt from personal danger those men who are often so zealous to fan the flame of discord and excite bloody wars. Indeed, for the same reasons which we have above alleged in favor of magistrates, an exemption from bearing arms should be allowed to such of the clergy as really useful, — to those who are employed in teaching religion, governing the church, and celebrating the public worship.4

But those immense multitudes of useless monks and friars, — those drones, who, under pretense of dedicating themselves to God, dedicate themselves in fact to sloth and effeminacy; — by what right do they pretend to a prerogative that is ruinous to the state? And if the prince exempts them from military service, is he not guilty of injustice to the other members, on whom he thus throws the whole burthen? I do not here mean to advise a sovereign to fill his armies with monks, but gradually to diminish a useless class of men, by depriving them of injurious and ill-founded privileges. History mentions a martial bishop5 whose weapon was a club, with which he knocked down the enemy, to avoid incurring the censure of the canon law by shedding their blood, it would be much more reasonable, when monks are exempted from carrying arms, that they should be employed in the work as pioneers, and thus made to alleviate the toil of the soldiers. They have, on many occasions, zealously undertaken the task in cases of necessity. I could mention more than one famous siege where monks have usefully served in defense of their country. When the Turks besieged Malta, the ecclesiastics, the women, the very children, all, according to their respective strength or capacity, contributed to that glorious defense, which baffled the utmost efforts of the Ottoman empire.

There is another class of idle drones, whose exemption is a still more glaring abuse, — I mean those swarms of useless footmen who crowd the dwellings of the great and the wealthy, — and who, by the very nature of their employment, are themselves corrupted in displaying the luxury of their masters.

§ 11. Soldiers’ pay and quarters.
Among the Romans, while every citizen took his turn to serve in the army, their service was gratuitous. But when a choice is made, and standing armies are kept on foot, the state is bound to pay them, as no individual is under an obligation to perform more than his quota of the public service: and if the ordinary revenues are not sufficient for the purpose, the deficiency must be provided for by taxation. It is but reasonable that those who do not serve should pay their defenders.

When the soldier is not in the field, he must necessarily be provided with quarters. The burthen, in such case, naturally falls on housekeepers: but as that is attended with many inconveniences, and proves very distressing to the citizens, it becomes a good prince, or a wise and equitable government, to ease them of it as far as possible. In this particular, the king of France has made magnificent and ample provision in many towns, by the erection of barracks for the accommodation of the garrison.

§ 12. Hospitals for invalids.
The asylums prepared for indigent soldiers and officers who are grown gray in the service, and whom toil or the enemy’s sword has rendered incapable of providing for their own subsistence, may be considered as part of the military pay. In France and England, magnificent establishments have been made in favor of invalids, which, while they discharge a debt of a sacred nature, do honor to the sovereign and the nation. The care of those unfortunate victims of war is the indispensable duty of every state, in proportion to its ability. It is repugnant, not only to humanity, but to the strictest justice that generous citizens, heroes who have shed their blood for the safety of their country, should be left to perish with want, or unworthily forced to beg their bread. The honorable maintenance of such persons might very properly be imposed upon rich convents and large ecclesiastical benefices. Nothing can be more just than that those citizens who avoid all the dangers of war, should bestow part of their riches for the relief of their valiant defenders.

§ 13. Mercenary soldiers.
Mercenary soldiers are foreigners voluntarily engaging to serve the state for money, or a stipulated pay. As they owe no service to a sovereign whose subjects they are not, the advantages he offers them are their sole motive. By enlisting, they incur the obligation to serve him; and the prince, on his part, promises them certain conditions, which are settled in the articles of enlistment. Those articles, being the rule and measure of the respective obligations and rights of the contracting parties, are to be religiously observed. The complaints of some French historians against the Swiss troops, who on several occasions formerly refused to march against the enemy, and even withdrew from the service, because they were not paid, — those complaints, I say, are equally ridiculous and unjust. Why should the articles of enlistment be more strongly binding on one of the parties than on the other? Whenever the prince fails to perform what he has promised, the foreign soldiers are discharged from any further duty to him. I own it would be ungenerous to forsake a prince who, without any fault on his own part, is by accident alone rendered for a while unable to make good his payments. There may even be occasions when such an inflexibility on the part of the soldier would be, if not contrary to strict justice, at least very repugnant to equity. But this was never the case with the Switzers: they never were known to quit the service on the first failure of payment; and when they perceived the good intentions of a sovereign laboring under a real inability to satisfy them, their patience and zeal always supported them under such difficulties. Henry the Fourth owed them immense sums: yet they did not, in his greatest necessities, abandon him; and that hero found the nation equally generous as brave, I here speak of the Switzers, because, in fact, those above alluded to were often mere mercenaries. But a distinction is to be made between troops of this kind and those Switzers who at present serve different powers, and with the permission of their sovereign, and in virtue of alliances subsisting between those powers and the Helvetic body, or some particular canton. The latter are real auxiliaries, though paid by the sovereign whom they serve.

Much has been said on the question — Whether the profession of a mercenary soldier be lawful or not? Whether individuals may, for money or any other reward, engage to serve a foreign prince in his wars? This question does not to me appear very difficult to be solved. Those who enter into such engagements without the express or tacit consent of their sovereign, offend against their duty as citizens. But if their sovereign leaves them at liberty to follow their inclination for a military life, they are perfectly free in that respect. Now, every free man may join whatever society he pleases, according as he finds it most to his advantage. He may make its cause his own, and espouse its quarrels. He becomes in some measure, at least for a time, a member of the state in whose service he engages: and as an officer is commonly at liberty to quit the service when he thinks proper, and the private soldier at the expiration of his engagement, — if that state embark in a war which is evidently unjust, the foreigner may quit its service. And the mercenary soldier, having now learned the art of war, has rendered himself more capable of serving his country, if ever she require his assistance. This last consideration will furnish us with an answer to a question proposed on this head — Whether the sovereign can with propriety permit his subjects to serve foreign powers indiscriminately for money? He can for this simple reason — that his subject will thus learn an art, of which a thorough knowledge is both useful and necessary. The tranquillity, the profound peace which Switzerland has so long enjoyed in the midst of all the commotions and wars which have agitated Europe, — that long repose would soon become fatal to her, did not her citizens, by serving foreign princes, qualify themselves for the operations of war, and keep alive their martial spirit.

§ 14. What is to be observed in their enlistment.
Mercenary soldiers enlist voluntarily. The sovereign has no right to compel foreigners: he must not even employ stratagem or artifice, in order to induce them to engage in a contract, which like all others, should be founded on candor and good faith.

§ 15. Enlisting in foreign countries.
As the right of levying soldiers belongs solely to the nation or the sovereign (§ 7), no person must attempt to enlist soldiers, in a foreign country, without the permission of the sovereign; and, even with that permission, none but volunteers are to be enlisted; for the service of their country is out of the question here; and no sovereign has a right to give or sell his subjects to another.

The man who undertakes to enlist soldiers in a foreign country, without the sovereign’s permission, — and, in general, whoever entices away the subjects of another state, violates one of the most sacred rights of the prince and the nation. This crime is distinguished by the name of kidnapping, or man-stealing, and is punished with the utmost severity in every well-regulated state. Foreign recruiters are hanged without mercy, and with great justice. It is not presumed that their sovereign has ordered them to commit a crime; and, supposing even that they had received such an order, they ought not to have obeyed it, — their sovereign having no right to command what is contrary to the law of nature. It is not, I say, presumed that these recruiters act by order of their sovereign; and with respect to such of them as have practiced seduction only, it is generally thought sufficient to punish them when they can be detected and caught: if they have used violence, and made their escape, it is usual to demand a surrender of the delinquents, and to claim the persons they have carried off. But if it appears that they acted by order, such a proceeding in a foreign sovereign is justly considered as an injury, and as a sufficient cause for declaring war against him, unless he makes suitable reparation.

§ 16. Obligation of soldiers.
All soldiers, natives or foreigners, are to take an oath to serve faithfully, and not desert the service. This is no more than what they are already obliged to, the former as subjects, the latter by their engagement; but their fidelity is of so great importance to the state, that too many precautions cannot be taken for rendering it secure. Deserters merit severe and exemplary punishment; and the sovereign may, if he thinks it necessary, annex the penalty of death to desertion. The emissaries who solicit them to desert are far more guilty than the recruiters mentioned in the preceding section.

§ 17. Military laws.
Good order and subordination, so useful in all places, are nowhere so necessary as in the army. The sovereign should exactly specify and determine the functions, duties, and rights of military men, — of soldiers, officers, commanders of corps, and generals. He should regulate and fix the authority of commanders in all the gradations of rank, — the punishments to be inflicted on offenders, — the form of trials, etc. The laws and ordinances relative to these several particulars form the military code.

§ 18. Military discipline.
Those regulations, whose particular tendency is to maintain order among the troops, and to enable them to perform their military service with advantage to the state, constitute what is called military discipline. This is of the highest importance. The Switzers were the first among the modern nations that revived it in its ancient vigor. It was a good discipline, added to the valor of a free people, that produced, even in the infancy of their republic, those brilliant achievements which astonished all Europe. Machiavel says that the Switzers are the masters of all Europe in the art of war.6 In our times, the Prussians have shown what may be expected from good discipline and assiduous exercise: soldiers, collected from all quarters, have, by the force of habit, and the influence of command, performed all that could be expected from the most zealous and loyal subjects.

§ 19. Subordinate powers in war.
Every military officer, from the ensign to the general, enjoys the rights and authority assigned him by the sovereign; and the will of the sovereign, in this respect, is known by his express declarations, contained either in the commissions he confers or in the military code, — or is, by fair deduction, inferred from the nature of the functions assigned to each officer; for every man who is intrusted with an employment is presumed to be invested with all the powers necessary to enable him to fill his station with propriety, and successfully discharge the several functions of his office.

Thus, the commission of a commander in chief, when it is simple and unlimited, gives him an absolute power over the army — a right to march it whither he thinks proper, to undertake such operations as he finds conducive to the service of the state, etc. It is true, indeed, that the powers of a general are often limited; but the example of Marshal Turenne sufficiently shows, that, when the sovereign is certain of having made a good choice, the best thing he can do in this respect is to give the general an unlimited power. Had the operations of the Duke of Marlborough depended on the directions of the cabinet, there is little probability that all his campaigns would have been crowned with such distinguished success.

When a governor is besieged in the place where he commands, and all communication with his sovereign is cut off, that very circumstance confers on him the whole authority of the state, so far as respects the defense of the town and the safety of the garrison.

These particulars merit the utmost attention, as they furnish a principle for determining what the several commanders, who are the subordinate or inferior powers in war, may execute with sufficient authority. Exclusive of the consequences which may be deduced from the very nature of their employments, we are likewise to consider the general practice and established usage in this respect. If it be a known fact, that, in the service of a particular nation, officers of a certain rank have been uniformly invested with such or such powers, it may reasonably be presumed that the person we are engaged with is furnished with the same powers.

§ 20. How their promises bind the sovereign.
Every promise made by any of the subordinate powers, by any commander within his department, in conformity to the terms of his commission and to the authority which he naturally derives from his office and the functions intrusted to his care, — every such promise, I say, is, for the reasons above alleged, made in the name and by the authority of the sovereign, and equally obligatory on him as if he had himself personally made it. Thus, a governor capitulates for the town which he commands, and for the garrison; and what he has promised, the sovereign cannot invalidate. In the last war, the general who commanded the French at Lintz, engaged to march back his troops on this side of the Rhine. Governors of towns have often promised that, for a limited time, their garrisons should not carry arms against the enemy with whom they capitulated: and these capitulations have always been faithfully observed

§ 21. In what cases their promises bind only themselves.
But, if a subordinate power allows himself a greater latitude, and exceeds the authority annexed to his office, his promise becomes no more than a private engagement, or what is called sponsio, of which we have already treated, (Book II. Chap. XIV.) This was the case with the Roman consuls at the Furcæ Caudinæ. They might, indeed, agree to deliver hostages, and that their army should pass under the yoke, etc., but they were not authorized to conclude a peace, as they took care to signify to the Samnites.

§ 22. Their assumption of an authority which they do not possess.
If a subordinate power assumes an authority which he does not possess, and thus deceives the party treating with him, though an enemy, — he is naturally responsible for the damage caused by his deception, and bound to make reparation. I say “though an enemy:” for the faith of treaties is to be observed between enemies, as all men of principle agree, and as we shall prove in the sequel. The sovereign of that fraudulent officer ought to punish him, and oblige him to repair his fault: it is a duty which the prince owes to justice, and to his own character.

§ 23. How they bind their inferiors.
Promises made by a subordinate power are obligatory on those who are subject to his control, and bind them in every particular in which he is authorized and accustomed to command their obedience: for, with respect to such particulars, he is vested with the sovereign authority, which his inferiors are bound to respect in his person. Thus, in a capitulation, the governor of a town stipulates and promises for his garrison, and even for the magistrates and citizens.


     1.    What are instruments of war, or contraband, and of the prohibitions respecting them, as regards neutral commerce, see Chitty’s L.N. 119 to 128; 1 Chitty’s Commercial Law, 445 to 449. L’art de la guerre n’est pas ainsi qu’on le croit vulgairement, l’art de detreure mais l’art de paralyser des forces de l’ennemi. Cours le Droit Public. — Paris, 1830; tom 2, pages 85, 86, & Id 406. — C.
     2.    But semble, that anciently the king might press men to serve on land as soldiers. Barrington’s Observations on Ancient Statutes, 334. The right of pressing men to serve in the Navy constitutes an exception. Its legality cannot now be effectually disputed, per Lord Mansfield, King v. Jubbs, Cowp. 517; per Lord Kenyon, 5 Term R. 276; 9 East, 466; 5 East, 477; 14 East, 346; 2 Camp. 320, and see Barrington’s Observations on Ancient Statutes, 334, 5 edit.; 1 Bla. Com. 420 n. 13. It should seem that every passenger on board a merchant ship is bound to assist in her defense; and if he refuse, he may be confined until all danger from the attack has subsided. Boyce v. Bailiff, 1 Campb. 60. — C.
     3.    Ibid.
     4.    Formerly bishops went to war in virtue of their fiefs, and led with them their vassals. The Danish bishops were not inattentive to a function which pleased them better than the peaceful cares of episcopacy. The famous Absalom, bishop of Roschild, and afterwards archbishop of Lunden, was the principal general of king Waldemarl. And since the use of regular troops has superseded that feudal service, there have not been wanting some martial prelates who eagerly courted the command of armies. The cardinal De la Valette, and Sourdis, archbishop of Bordeaux, appeared in arms under the ministry of cardinal Richelieu, who also acted himself in a military capacity at the attack of the pass of Susa. This is an abuse which the church very justly opposes. A bishop makes a better appearance in his proper station, in his diocese, than in the army; and, at present, sovereigns are in no want of generals and officers, who will perform more useful services than can be expected from churchmen. In short, let every person keep to his vocation. All I dispute with the clergy, is their exemption as matter of right and in cases of necessity. — Ed. 1797.
     5.    A bishop of Beauvais, under Philip Augustus. He fought at the battle of Bouvines.
     6.    Disc. on Livy.