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

Emmerich de Vattel

Of the Observance and Breach of the Treaty of Peace

§ 35. The treaty of peace binds the nation and successors.
THE treaty of peace concluded by a lawful power is undoubtedly a public treaty, and obligatory on the whole nation (Book II. § 154). It is likewise, by its nature, a real treaty; for if its duration had been limited to the life of the sovereign, it would be only a truce, and not a treaty of peace. Besides, every treaty which, like this, is made with a view to the public good, is a real treaty (Book II. § 198). It is therefore as strongly binding on the successors as on the prince himself who signed it, since it binds the state itself, and the successors can never have, in this respect, any other rights than those of the state.

§ 36. It is to be faithfully observed.
After all we have said on the faith of treaties and the indispensable obligation which they impose, it would be superfluous to use many words in showing how religiously treaties of peace in particular should be observed both by sovereigns and people. These treaties concern and bind whole nations; they are of the highest importance; the breach of them infallibly rekindles the flames of war; — all which considerations give additional force to the obligation of keeping our faith, and punctually fulfilling our promises.

§ 37. The plea of fear or force does not dispense with the observance.
We cannot claim a dispensation from the observance of a treaty of peace, by alleging that it was extorted from us by fear, or wrested from us by force. In the first place, were this plea admitted, it would destroy, from the very foundations, all the security of treaties of peace; for there are few treaties of that kind, which might not be made to afford such a pretext, as a cloak for the faithless violation of them. To authorize such an evasion would be a direct attack on the common safety and welfare of nations: — the maxim would be detestable, for the same reasons which have universally established the sacredness of treaties (Book II. § 220). Besides, it would generally be disgraceful and ridiculous to advance such a plea. At the present day, it seldom happens that either of the belligerent parties perseveres to the last extremity before he will consent to a peace. Though a nation may have lost several battles, she can still defend herself: as long as she has men and arms remaining, she is not destitute of all resource. If she thinks fit, by a disadvantageous treaty, to procure a necessary peace, — if by great sacrifices she delivers herself from imminent danger or total ruin, — the residue which remains in her possession is still an advantage for which she is indebted to the peace: it was her own free choice to prefer a certain and immediate loss, but of limited extent, to an evil of a more dreadful nature, which, though yet at some distance, she had but too great reason to apprehend.

If ever the plea of constraint may be alleged, it is against an act which does not deserve the name of a treaty of peace, — against a forced submission to conditions which are equally offensive to justice and all the duties of humanity. If an unjust and rapacious conqueror subdues a nation, and forces her to accept of hard, ignominious, and insupportable conditions, necessity obliges her to submit; but this apparent tranquillity is not a peace; it is an oppression which she endures only so long as she wants the means of shaking it off, and against which men of spirit rise on the first favorable opportunity. When Ferdinand Cortes attacked the empire of Mexico without any shadow of reason, without even a plausible pretext, — if the unfortunate Montezuma could have recovered his liberty by submitting to the iniquitous and cruel conditions of receiving Spanish garrisons into his towns and his capital, of paying an immense tribute, and obeying the commands of the king of Spain, — will any man pretend to assert that he would not have been justifiable in seizing a convenient opportunity to recover his rights, to emancipate his people, and to expel or exterminate the Spanish horde of greedy, insolent, and cruel usurpers? No! such a monstrous absurdity can never be seriously maintained. Although the law of nature aims at protecting the safety and peace of nations by enjoying the faithful observances of promises, it does not favor oppressors. All its maxims tend to promote the advantage of mankind: that is the end of all laws and rights. Shall he, who with his own hand tears asunder all the bonds of human society, be afterwards allowed to claim the benefit of them? Even though it were to happen that this maxim should be abused, and that a nation should, on the strength of it, unjustly rise in arms and recommence hostilities, — still it is better to risk that inconvenience than to furnish usurpers with an easy mode of perpetuating their injustice, and establishing their usurpation on a permanent basis. Besides, were you to preach up the contrary doctrine which is so repugnant to all the feelings and suggestions of nature, where could you expect to make proselytes?

§ 38. How many ways a treaty of peace may be broken.
Equitable agreements, therefore, or at least such as are supportable, are alone entitled to the appellation of treaties of peace: these are the treaties which bind the public faith, and which are punctually to be observed, though in some respects harsh and burdensome. Since the nation consented to them, she must have considered them as in some measure advantageous under the then existing circumstances; and she is bound to respect her promise. Were men allowed to rescind at a subsequent period those agreements to which they were glad to subscribe on a former occasion, there would be an end to all stability in human affairs.

The breach of a treaty of peace consists in violating the engagements annexed to it, either by doing what it prohibits, or by not doing what it prescribes. Now, the engagements contracted by treaty maybe violated in three different ways, — either by a conduct that is repugnant to the nature and essence of every treaty of peace in general, — by proceedings which are incompatible with the particular nature and essence of every treaty of peace in general, — by proceedings which are incompatible with the particular nature of the treaty in question, — or, finally, by the violation of any article expressly contained in it.

§ 39. By a conduct contrary to the nature of every treaty of peace.
First, a nation acts in a manner that is repugnant to the nature and essence of every treaty of peace, and to peace itself, when she disturbs it without cause, either by taking up arms and recommencing hostilities without so much as a plausible pretext, or by deliberately and wantonly offending the party with whom she has concluded a peace, and offering such treatment of him or his subjects as is incompatible with the state of peace, and such as he cannot submit to without being deficient in the duty which he owes to himself. It is likewise acting contrary to the nature of all treaties of peace to take up arms a second time for the same subject that had given rise to the war which has been brought to a conclusion, or through resentment of any transaction that had taken place during the continuance of hostilities. If she cannot allege at least some plausible pretext borrowed from a fresh cause, which may serve to palliate her conduct, she evidently revives the old war that was extinct, and breaks the treaty of peace.

§ 40. To take up arms for a fresh cause is no breach of the treaty of peace.
But to take up arms for a fresh cause is no breach of the treaty of peace: for though a nation has promised to live in peace, she has not therefore promised to submit to injuries and wrongs of every kind, rather than procure justice by force of arms. The rupture proceeds from him who, by his obstinate injustice, renders this method necessary.

But here it is proper to recall to mind what we have more than once observed, — namely, that nations acknowledge no common judge on earth, — that they cannot mutually condemn each other without appeal, — and, finally, that they are bound to act in their quarrels as if each was equally in the right. On this footing, whether the new cause which gives birth to hostilities be just or not, neither he who makes it a handle for taking up arms, nor he who refuses satisfaction, is reputed to break the treaty of peace, provided the cause of complaint on the one hand, and the refusal of satisfaction on the other, have at least some color of reason, so as to render the question doubtful. When nations cannot come to any agreement on questions of this kind, their only remaining resource is an appeal to the sword. In such case the war is absolutely a new one, and does not involve any infraction of the existing treaty.

§ 41. A subsequent alliance with an enemy is likewise no breach of the treaty.
And as a nation, in making a peace, does not thereby give up her right of contracting alliances and assisting her friends, it is likewise no breach of the treaty of peace to form a subsequent alliance with the enemies of the party with whom she has concluded such treaty, — to join them, to espouse their quarrel, and unite her arms with theirs, — unless the treaty expressly prohibits such connections. At most, she can only be said to embark in a fresh war in defense of another people’s cause.

But I here suppose these new allies to have some plausible grounds for taking up arms, and that the nation in question has just and substantial reasons for supporting them in the contest. Otherwise, to unite with them just as they are entering on the war, or when they have already commenced hostilities, would be evidently seeking a pretext to elude the treaty of peace, and no better, in fact, than an artful and perfidious violation of it.

§ 42. Why a distinction is to be made between a new war and a breach of the treaty.
It is of great importance to draw a proper distinction between a new war and the breach of an existing treaty of peace, because the rights acquired by such treaty still subsist, notwithstanding the new war: whereas they are annulled by the rupture of the treaty on which they were founded. It is true, indeed, that the party who had granted those rights does not fail to obstruct the exercise of them during the course of the war, as far as lies in his power, — and even may, by the right of arms, wholly deprive his enemy of them, as well as he may wrest from him his other possessions. But in that case he withholds those rights as things taken from the enemy, who, on a new treaty of peace, may urge the restitution of them. In negotiations of that kind, there is a material difference between demanding the restitution of what we were possessed of before the war, and requiring new concessions, a little equality in our successes entitles us to insist on the former, whereas nothing less than a decided superiority can give us a claim to the latter. It often happens, when nearly equal success has attended the arms of both parties, that the belligerent powers agree mutually to restore their conquests, and to replace every thing in its former state. When this is the case, if the war in which they were engaged was a new one, the former treaties still subsist; but if those treaties were broken by taking up arms a second time for the same subject, and an old war was revived, they remain void; so that, if the parties wish they should again take effect, they must expressly specify and confirm them in their new treaty.

The question before us is highly important in another view also, — that is, in its relation to other nations who may be interested in the treaty, inasmuch as their own affairs require them to maintain and enforce the observance of it. It is of the utmost consequence to the guarantees of the treaty, if there are any, — and also to the allies, who have to discover and ascertain the cases in which they are bound to furnish assistance. Finally, he who breaks a solemn treaty is much more odious than the other, who, after making an ill-grounded demand, supports it by arms. The former adds perfidy to injustice: he strikes at the foundation of public tranquillity; and as he thereby injures all nations, he affords them just grounds for entering into a confederacy in order to curb and repress him. Wherefore, as we ought to be cautious of imputing the more odious charge, Grotius justly observes, that, in a case of doubt, and where the recurrence to arms may be vindicated by some specious pretext resting on a new ground, “it is better that we should, in the conduct of him who takes up arms anew, presume simple injustice, unaccompanied by perfidy, than account him at once guilty both of perfidy and injustice.”1

§ 43. Justifiable self-defense is no breach of the treaty.
Justifiable self-defense is no breach of the treaty of peace. It is a natural right which we cannot renounce: and, in promising to live in peace, we only promise not to attack without cause, and to abstain from injuries and violence. But there are two modes of defending our persons or our property; sometimes the violence offered to us will admit of no other remedy than the exertion of open force; and under such circumstances, we may lawfully have recourse to it. On other occasions, we may obtain redress for the damage and injury by gentler methods; and to these we ought of course to give the preference. Such is the rule of conduct which ought to be observed by two nations that are desirous of maintaining peace, whenever the subjects of either have happened to break out into any act of violence. Present force is checked and repelled by force. But, if there is question of obtaining reparation of the damage done, together with adequate satisfaction for the offence, we must apply to the sovereign of the delinquents: we must not pursue them into his dominions, or have recourse to arms, unless he has refused to do us justice. If we have reason to fear that the offenders will escape, — as, for instance, if a band of unknown persons from a neighboring country have made an irruption into our territory, — we are authorized to pursue them with an armed force into their own country, until they be seized; and their sovereign cannot consider our conduct in any other light than that of just and lawful self-defense, provided we commit no hostilities against innocent persons.

§ 44. Causes of rupture on account of allies.
When the principal contracting party has included his allies in the treaty, their cause becomes in this respect inseparable from his; and they are entitled, equally with him, to enjoy all the conditions essential to a treaty of peace; so that any act, which, if committed against himself, would be a breach of the treaty, is no less a bleach of it, if committed against the allies whom he has caused to be included in his treaty. If the injury be done to a new ally, or to one who is not included in the treaty, it may, indeed, furnish a new ground for war, but is no infringement of the treaty of peace.

§ 45. 2. The treaty is broken by what is contrary to its particular nature.
The second way of breaking a treaty of peace is by doing any thing contrary to what the particular nature of the treaty requires. Thus, every procedure that is inconsistent with the rules of friendship is a violation of a treaty of peace which has been concluded under the express condition of thenceforward living in amity and good understanding.

To favor a nation’s enemies, — to give harsh treatment to her subject, — to lay unnecessary restrictions on her commerce, or give another nation a preference over her without reason, — to refuse assisting her with provisions, which she is willing to pay for, and we ourselves can well spare, — to protect her factious or rebellious subjects, — to afford them an asylum, — all such proceedings are evidently inconsistent with the laws of friendship. To this list, may, according to circumstances, be also added — the building of fortresses on the frontiers of a state, — expressing distrust against her, — levying troops, and refusing to acquaint her with the motives of such step, etc.2 But, in affording a retreat to exiles, — in harboring subjects who chose to quit their country, without an intention of injuring it by their departure, and solely for the advantage of their private affairs, — in charitably receiving emigrants who depart from their country with a view to enjoy liberty of conscience elsewhere, — there is nothing inconsistent with the character of a friend. The private laws of friendship do not, according to the caprice of our friends, dispense with our observance of the common duties of humanity which we owe to the rest of our species.

§ 46. 3. By the violation of any article.
Lastly, the peace is broken by the violation of any of the express articles of the treaty. This third way of breaking it is the most decisive, the least susceptible of quibble or evasion. Whoever fails in his engagements annuls the contract as far as depends on him: — this cannot admit of a doubt.

§ 47. The violation of a single article breaks the whole treaty.
But it is asked whether the violation of a single article of the treaty can operate a total rupture of it? Some writers,3 here drawing a distinction between the articles that are connected together (connexi) and those that stand detached and separate (diversi), maintain, that, although the treaty be violated in the detached articles, the peace nevertheless still subsists with respect to the others, But, to me, the opinion of Grotius’ appears evidently founded on the nature and spirit of treaties of peace. That great man says that all the articles of one and the same treaty are conditionally included in each other, as if each of the contracting parties had formally said, “I will do such or such thing, provided that, on your part, you do so and so;”4 and he justly adds, that, when it is designed that the engagement shall not be thereby rendered ineffectual, this express clause is inserted, — that, “though any one of the articles of the treaty may happen to be violated, the others shall subsist in full force.” Such an agreement may unquestionably be made. It may likewise be agreed that the violation of one article shall only annul those corresponding to it, and which, as it were, constitute the equivalent to it. But, if this clause be not expressly inserted in the treaty of peace, the violation of a single article overthrows the whole treaty, as we have proved above, in speaking of treaties in general (Book II. § 202).

§ 48. Whether a distinction may here be made between the more and the less important articles.
It is equally nugatory to attempt making a distinction in this instance between the articles of greater and those of lesser importance. According to strict justice, the violation of the most trifling article dispenses the injured party from the observance of the others, since they are all, as we have seen above, connected with each other, as so many conditions. Besides, what a source of dispute will such a distinction lay open! Who shall determine the importance of the article violated? We may, however, assert with truth, that, to be ever ready to annul a treaty on the slightest cause of complaint, is by no means consonant to the reciprocal duties of nations, to that mutual charity, that love of peace, which should always influence their conduct.

§ 49. Penalty annexed to the violation of an article.
In order to prevent so serious an inconvenience, it is prudent to agree on a penalty to be suffered by the party who violates any of the less important articles: and then, on his submitting to the penalty, the treaty still subsists in full force. In like manner, there may, to the violation of each individual article, be annexed a penalty proportionate to its importance. We have treated of this subject in our remarks on truces (Book III, § 243), to which we refer the reader.

§ 50. Studied delays
Studied delays are equivalent to an express denial, and differ from it only by the artifice with which he who practices them seeks to palliate his want of faith: he adds fraud to perfidy, and actually violates the article which he should fulfill.

§ 51. Insurmountable impediments.
But, if a real impediment stand in the way, time must be allowed; for no one is bound to perform impossibilities. And for the same reason, if any insurmountable obstacle should render the execution of an article not only impracticable for the present, but for ever impossible, no blame is imputable to him who had engaged for the performance of it; nor can his inability furnish the other party with a handle for annulling the treaty; but the latter should accept of an indemnification, if the case will admit of it, and the indemnification be practicable. However, if the thing which was to have been performed in pursuance of the article in question be of such a nature that the treaty evidently appears to have been concluded with a sole view to that particular thing, and not to any equivalent, — the intervening impossibility undoubtedly cancels the treaty. Thus, a treaty of protection becomes void when the protector is unable to afford the promised protection, although his inability does not arise from any fault on his part. In the same manner, also, whatever promises a sovereign may have made on condition that the other party should procure him the restoration of an important town, he is released from the performance of every thing which he had promised as the purchase of the recovery, if he cannot be put in possession. Such is the invariable rule of justice. But rigid justice is not always to be insisted on: — peace is so essential to the welfare of mankind, and nations are so strictly bound to cultivate it, to procure it, and to re-establish it when interrupted, — that, whenever any such obstacles impede the execution of a treaty of peace, we ought ingenuously to accede to every reasonable expedient, and accept of equivalents or indemnifications, rather than cancel a treaty of peace already concluded, and again have recourse to arms.

§ 52. Infractions of the treaty of peace by the subjects;
We have already, in an express chapter (Book II. Chap. VI.), examined how and on what occasions the actions of subjects may be imputed to the sovereign and the nation. It is by what circumstance we must be guided in determining how far the proceedings of the subjects may be capable of annulling a treaty of peace. They cannot produce such effect unless so far as they are imputable to the sovereign. He who is injured by the subjects of another nation takes satisfaction for the offence, himself, when he meets with the delinquents in his own territories, or in a free place, as, for instance, on the open sea; or if it be more agreeable to him, he demands justice of their sovereign. If the offenders are refractory subjects, no demand can be made on their sovereign; but whoever can seize them, even in a free place, executes summary justice on them himself. Such is the mode observed towards pirates: and, in order to obviate all misunderstandings, it is generally agreed that the same treatment be given to all private individuals who commit acts of hostility without being able to produce a commission from their sovereign.

§ 53. Or by allies.
The actions of our allies are still less imputable to us than those of our subjects. The infractions of a treaty of peace by allies, even by those who have been included in it, or who joined in it as principals, can therefore produce no rupture of it except with regard to themselves, and do not affect it in what concerns their ally, who, on his part, religiously observes his engagements. With respect to him, the treaty subsists in full force, provided he do not undertake to support the cause of those perfidious allies, if he furnishes them with such assistance as he cannot be bound to give them on an occasion of this nature, he espouses their quarrel, and becomes an accomplice in their breach of faith. But, if he has an interest in preventing their ruin, he may interpose, and, by obliging them to make every suitable reparation, save them from an oppression of which he would himself collaterally feel the effects. It even becomes an act of justice to undertake their defense against an implacable enemy, who will not be contented with an adequate satisfaction.

§ 54. Right of the offended party against him who has violated the treaty.
When the treaty of peace is violated by one of the contracting parties, the other has the option of either declaring the treaty null and void, or allowing it still to subsist: for a contract which contains reciprocal engagements, cannot be binding on him with respect to the party who on his side pays no regard to the same contract. But, if he chooses not to come to a rupture, the treaty remains valid and obligatory. It would be absurd that he who had been guilty of the violation should pretend that the agreement was annulled by his own breach of faith: this would, indeed, be an easy way of shaking off engagements, and would reduce all treaties to empty formalities. If the injured party be willing to let the treaty subsist, he may either pardon the infringement, — insist on an indemnification or adequate satisfaction, — or discharge himself, on his part, from those engagements corresponding with the violated article, — those promises he had made in consideration of a thing which has not been performed. But, if he determines on demanding a just indemnification, and the party in fault refuses it, then the treaty is necessarily broken, and the injured party has a very just cause for taking up arms again. And indeed this is generally the case; for it seldom happens that the infractor will submit to make reparation, and thereby acknowledge himself in fault.


     1.    Lib. iii. cap. 20, § 28.
     2.    And see, ante. Book III. c. 3, as to what are just causes of war. — C.
     3.    See Wolf. Jus Gent. §§ 1022, 1023.
     4.    Lib. iii. cap. xix. § 14.