The Law of War and Peace (1625)

by Hugo Grotius

On War That Is Lawful or Public According to the Law of Nations; and Therein, on the Declaration of War

I.     A public war according to the law of nations is a war between different peoples.
1.   In a previous passage we began to say that by authors, of repute a war is often called lawful not from the cause from which it arises, nor, as is done in other cases, from the importance of its, exploits, but because of certain peculiar legal consequences. Of what sort a lawful war is, however, will best be perceived from the definition of enemies given by the Roman jurists.

‘Enemies are those who in the name of the state declare war upon us, or upon whom we in the name of the state declare war; others are brigands and robbers,’ says Pomponius. Similarly Ulpian:

Enemies are those upon whom the Roman people have publicly declared war, or who, have themselves declared war upon the Roman people; others are called thieves and brigands. And so he who has been captured by robbers is not their slave, and has no need of the right of postliminy. But he who has been captured by enemies, as by the Germans or Parthians, is a slave of the enemy, and recovers his former status by postliminy.

Paul says: ‘Those who are captured by pirates and brigands remain free.’ There is a further statement by Ulpian:

In civil contentions, although the state is thereby often injured, nevertheless the destruction of the state is not aimed at; the citizens who support either side after the manner of enemies are not in the position of those who possess rights of captivity or postliminy. In consequence it has been decided that for those who have been captured, sold, and later set free, it would be superfluous to attempt to recover from the emperor their free status, which they had not lost by captivity.

2.   It needs only to be noted further that we may understand. that any one who has the supreme authority in a state may take the, place of the Roman people in our illustration. ‘An enemy,’ says Cicero, ‘is the one that has a state, a senate, a treasury, the agreement and concord of the citizens, and the power, if the course of events’ leads thereto, to conclude peace and an alliance.’

II.     The distinction between a people, although acting unjustly, and pirates or brigands.
1.   Moreover, a commonwealth or state does not immediately cease to be such if it commits an injustice, even as a body; and a gathering of pirates and brigands is not a state, even if they do perhaps mutually maintain a sort of equality, without which no association can exist. The reason is that pirates and brigands are banded together for wrongdoing; the members of a state, even if at times they are not free from crime, nevertheless have been united for the enjoyment of rights, and they do render justice to foreigners. If the treatment of members of other states is not in all respects according to the law of nature, which, as we have showed elsewhere, has become partly obscured among many peoples, it is at least according to agreements entered into with each state or in accordance with customs.

Accordingly the scholiast on Thucydides notes that, at the time when it was considered legitimate to plunder at sea, the Greeks refrained from murder and raids by night, and from the seizure of the cattle of ploughmen. Strabo relates that other peoples also, who lived in like manner by plunder, upon returning home after being at sea, sent word to the owners in order that these might, if they wished, recover their stolen property at a fair price. To such persons applies the passage in Homer’s Odyssey, XIV:

      Themselves eager for loot, who to the land
      Of strangers fare; if gods above grant booty,
      With laden ships they leave and homeward go,
      And dread fear falls on those they leave behind.

2.   In moral questions, furthermore, the principal element is considered as determining the essential character. As Cicero has rightly said in the fifth book On Ends: ‘The whole of an object takes its name from that constituent of it which comprises the most important elements and has the most far-reaching effect.’ With this accords the saying of Galen: ‘Names are taken from the most potent element in the compound.’ The same author often designates such things as ‘named after the chief element.’

Cicero, then, spoke too sweepingly when he said, On the Commonwealth, Book III, that where an unjust man is king, or where the aristocracy or the people itself is unjust, there is not a wicked state, but none at all. In correction of this view Augustine says: ‘Nevertheless, I should not go so far as to assert that the people as such does not exist, or that its organization is not a state, so long as there remains some sort of union in a reasoning populace, associated through harmonious participation in the things which it chooses.’ A body that is sick is nevertheless a body still; and a state, although seriously diseased, is a state so long as there remain tribunals and the other agencies that are necessary in order that foreigners, no less than private citizens, in their relations one with the other may there obtain their rights. Dio Chrysostom offers a more correct judgement in saying that the law (especially that which goes to make up the universal common law) exists in a state just as the mind in the human body; for when this is taken away the state ceases to exist.’ In the speech in which he urges the Rhodians to harmony, Aristides shows that many good laws may exist even under a tyranny. Aristotle in his Republic [Politics], Book V, chapter ix, says that if any one presses the violence of the few, or of the people, too far, the state first becomes full of faults, and finally ceases to be.

Let us illustrate this subject by examples.

3.   We heard Ulpian saying above that captives taken by brigands do not belong to those who capture them. He says further that captives taken by the Germans lose their freedom. And yet among the Germans marauding expeditions which are sent beyond the borders of a state ‘involve no disgrace,’ as Caesar states. Of the Venedi, Tacitus says: ‘With their marauding expeditions they overrun the forests and mountains that lie between the Peucini and the Fenni.’ In another place he says that the Chatti, a famous people of Germany, engaged in marauding expeditions. In the same author the Garamates are a nation fertile in marauding expeditions, but still a nation.

The Illyrians without distinction were accustomed to plunder on the sea, vet a triumph was celebrated over them; Pompey celebrated no triumph over the pirates. So great is the distinction between a people, however wicked it may be, and those who, although not forming a people, associate together’ for the sake of crime.

III.     Sometimes a transformation is effected.
Nevertheless a transformation may take place, not merely in the case of individuals, as when Jephthes, Arsaces, and Viriathus instead of being leaders of brigands became lawful chiefs, but also in the case of groups, so that those who have only been robbers upon embracing another mode of life’ become a state. In discussing brigandage Augustine says: ‘If by accessions of desperate men this evil grows to such proportions that it holds lands, establishes fixed settlements, seizes upon states and subjugates peoples, it assumes the name of a kingdom.’

IV.     It is essential to the nature of a public war that it should have the support of the sovereign power; in what way this is to be understood.
What persons have the sovereign power, we have already stated. Hence it may be understood that, if any possess the sovereign power in part, they may to that extent wage a lawful war.

This principle applies with even greater force to those who are not subjects, but are allied on an unequal footing.’ So we learn from history that all formalities of lawful war were observed between the Romans and their allies, the Volsci, Latins, Spaniards, and Carthaginians, although these had an inferior status in the alliance.

V.     A declaration of war is also requisite.
That a war may be lawful in the sense indicated, it is not enough that it be waged by sovereign powers on each side. It is also necessary, as we have said, that it should be publicly declared, and in fact, proclaimed so publicly that the notification of this declaration be made by one of the parties to the other; whence Ennius spoke of battles proclaimed in advance. In the first book On Duties Cicero says: ‘But the right usage of war has indeed been most scrupulously prescribed by the fetial law of the Roman people. According to this we are given to understand that no war is lawful unless it is waged for the recovery of property, or has been previously threatened and proclaimed.’

More concisely speaks an ancient writer in Isidore: ‘A lawful war is one that is waged by declaration, for the recovery of property or to repel enemies.’ Thus Livy, in his description of a lawful war, says that the war is waged openly and in accordance with public decree. Also, after relating that the Acarnanians had laid waste Attic territory, he adds: ‘This was the first manifestation of hostile feeling; afterward a lawful war was declared by decrees and voluntary proclamations of the states.’

VI.     What element in the declaration of war is in accordance with the law of nature, and what is peculiar to the law of nations, is set forth with distinctions.
1.   To understand the foregoing passages, and others dealing with the declaration of war, we must carefully distinguish what is due according to the law of nature, what is not due by nature but is honorable, what is required by the law of nations to secure the effects peculiar to this law, and what, in addition, is derived from the particular institutions of certain peoples.

In a case where either an attack is being warded off, or a penalty is demanded from the very person who has done wrong, no declaration is required by the law of nature. This is what Sthenelaidas, the ephor, says in Thucydides: ‘We who have been wronged in more than words are not to seek satisfaction in words or judicial proceedings.’ Latinus in Dionysius of Halicarnassus declares: ‘Every one who is attacked repels him who begins the war.’ Aelianus, quoting from Plato, says that a war which is undertaken to repel force is proclaimed, not by a herald, but by nature. Hence Dio Chrysostom, in his address To the Nicomedians, says: ‘Most wars begin without declaration.’

For no other reason Livy criticizes Menippus, an officer of Antiochus, because he had slain certain Romans when war had not yet been declared, and when no hostilities had been engaged in, so that they could have heard that swords had been drawn or even that blood had been shed; by this he shows that either of these two steps could have sufficed to justify the action. Not more necessary, by the law of nature, is a declaration of war in case an owner wishes to seize what belongs to him.

2.   But whenever one thing is seized in place of another, or the property of a debtor is taken for his debt, and all the more if one wishes to take possession of the property of those who are subject to the debt, then a demand for settlement is required, to establish the fact that it is impossible in any other way to obtain what is ours, or what is owed to us. For this is not a primary right, but a secondary and vicarious right, as we have elsewhere explained. Thus, even before the possessor of sovereign power is attacked for the debt or crime of a subject, a demand for settlement should be made, which may place him in the wrong, and in consequence of which he may be held either to be causing us loss or to be himself committing a crime, according to the principles which have previously been discussed.

3.   But even in case the law of nature does not require that such a demand be made, still it is honorable and praiseworthy to make it,’ in order that, for instance, we may avoid giving offence, or that the wrong may be atoned for by repentance and compensation, according to what we have said regarding the means to be tried to avoid war. Here applies this verse also:

      At first no one has sought to try extremes.

Here, too, applies the command which God gave to the Jews, that they should first invite to peace the city which was to be attacked. This command, although given to that people for a particular case, has been wrongly confused by some with the law of nations. For the peace there referred to is not peace in general, but one dependent upon a condition of subjection and tribute. When Cyrus came into the territory of the Armenians, before doing harm to any one he sent to the king those who represented him in order to demand the tribute and soldiery due according to the treaty, ‘thinking that this was a more friendly procedure than to advance without a previous declaration,’ as Xenophon says in his History. But by the law of nations a proclamation is required in all cases in order to secure these particular effects, not, however, from both parties but from either one.

VII.     A declaration of war is sometimes conditional, sometimes absolute.
1.   Now the declaration of war is either conditional or absolute. It is conditional when it is joined with a demand for restitution. Moreover, under the title of things sought in recovery the fetial law included not merely a claim by right of ownership, but also the effort to obtain that which is owed on a civil or criminal charge, as Servius’ rightly explains. Hence arises this phase in the formulas, ‘to be restored, satisfied, surrendered,’ where, as we have elsewhere’ said,’ surrendered’ must be understood with a reservation, to wit unless those on whom the demand is made prefer to punish the guilty party themselves. Pliny bears witness that this demand for restitution was called a ‘verbal demand.’

A conditional declaration is recorded by Livy: ‘That they would themselves use every means to free themselves from this injury unless it were removed by those who had inflicted it.’ Another is given by Tacitus: ‘unless they should inflict punishment upon the guilty, he would carry out a general massacre.’ There is also an ancient example in the Suppliants of Euripides, when Theseus gives to the herald these instructions for his mission to Creon the Theban:

      Theseus, who holds the neighboring kingdom’s soil,
      The dead demands for burial; granted that,
      Erechtheus’ people will become your friend.
      If this with favor meet, retrace thy steps;
      But if no heed is given, these other words employ
      Let them soon look to see my youth in arms.

Papinius in his description of the same event has:

      Proclaim either funeral pyres for the Danai
      Or for Thebes, battles.

Polybius calls this ‘to give notice of reprisals,’ and the ancient Romans ‘to give formal notice.’

An absolute declaration is what is called in particular a proclamation or edict. This is made when one party either has begun hostilities (and this is what in Isidore is said to be a war for the repulse of enemies), or has himself committed crimes that call for punishment.,

2.   Sometimes, indeed, an absolute declaration follows one that is conditional, although this is not necessary but superfluous. Hence arises the formula:

      I bear witness that this people is unjust, and does not give satisfaction.

There is also a second formula:

Whatever things, disputes, causes of complaint, of which the pates patratus of the Roman people of the Quirites has formally notified the pates patratus of the people of the Ancient Latins, which things the men of the Ancient Latins ought to have surrendered, done, paid, which things they have not paid nor surrendered nor done, these things I hold ought to be sought in just and righteous warfare; and I agree and approve.

The third formula is:

Whereas the tribes of the Ancient Latins have acted and committed offences against the Roman people of the Quirites, whereas the Roman people of the Quirites has ordered that there be war with the Ancient Latins, and the Senate of the Roman people of the Quirites has decreed, consented, agreed that war should be waged with the Ancient Latins, for this cause I and the Roman people declare and make war upon the tribes of the Ancient Latins.

That in this case, as I have said, a proclamation is not strictly necessary, becomes apparent from the fact that it was formally made at the nearest garrison point. So the fetials declared when consulted in the case of Philip of Macedon, and afterward in the case of Antiochus, since the first proclamation had to be made to the person who was attacked in the war. The declaration against Pyrrhus was in fact made to one of his soldiers, and that too in the Circus Flaminius, where this soldier was ordered to purchase a bit of ground for form’s sake, as Servius narrates in his commentary on the ninth book of the Aeneid.

3.   Further proof of the superfluity of this formality is found in the fact that war is often declared by both parties. Thus the Peloponnesian War was declared by the Corcyreans and by the Corinthians, although it is sufficient that such a declaration be made by either one party or the other.

VIII.     What elements in declarations of war pertain to municipal law and not to the law of nations.
To the customs and institutions of certain peoples, moreover, and not to the law of nations, belong the use of the herald’s staff among the Greeks; the sacred herbs and bloody spear used first by the Aequicolae, then by the Romans, who followed their example; the renunciation of any existing friendship or alliance; the period of thirty days set after the demand for restitution; the hurling of the spear the second time; and other formalities of this sort which should not be confused with those that properly belong to the law of nations.

Arnobius informs us that in his time a great part of these formalities had ceased to be observed; and, indeed, some were already neglected in the time of Varro. The third Punic War was begun at the same time with the declaration. In Dio, Maecenas holds that certain of these formalities are peculiar to a democratic state.

IX.     A war declared against any one is at the same time declared against his subjects and allies, in so far as they take his side.
Furthermore, a war declared against him who holds the sovereign authority in a state is held to be declared at the same time not only upon all his subjects, but also upon all who will join him as allies in such a way as to become an accession to him. This is what the more modern jurists mean when they say that defiance of the prince is defiance of his supporters; for to declare war they call to send forth defiance.

This principle is to be understood as applicable to the type of war waged against him upon whom it has been declared in the manner illustrated in the war against Antiochus. It was decided not to declare war against the Aetolians separately, because they had openly associated themselves with Antiochus. ‘The Aetolians have voluntarily declared war against themselves,’ was the response of the fetials.

X.     A war declared against any one is not held to be at the same time declared against his subjects and allies in so far as they are considered by themselves; illustration by examples.
If, on the conclusion of a war declared against one who holds the sovereign power, another people or king is to be attacked, because of the aid that they have furnished, a new declaration of war will have to be made in order to meet the requirements of the law of nations. For in such a case the people or king is now not regarded as an accessory, but as a principal. It was therefore rightly said that the war of Manilius against the Gallo-Grecians and that of Caesar against Ariovistus were not lawful wars according to the law of nations.’ The Gallo-Grecians and Ariovistus were in fact attacked not as accessories to another war, but principals; and for such a procedure by the Roman law a new authorization of the Roman people was required, just as a new declaration was required by the law of nations.

What was said in putting the question in regard to the war against Antiochus: ‘Did they desire, and did they direct, that war be begun with King Antiochus and with any who had espoused his cause,’ also what was provided in the decree against King Perseus, should, as it seems, be understood as meaning, so long as there should be a war with Antiochus or Perseus, and as referring to those who actually had a part in this war.

XI.     The reason why a declaration is required in order to secure certain effects.
Furthermore the reason why nations required a declaration for the kind of war which we have called lawful according to the law of nations was not that which some adduce, with the purpose that nothing should be done secretly or deceitfully, for this pertains to an exhibition of courage rather than to law, just as certain nations are said to have even appointed the date and place of battle.’ The purpose was, rather, that the fact might be established with certainty that war was being waged not by private initiative but by the will of each of the two peoples or of their heads.

From this consideration arise the peculiar effects which do not develop in a war against brigands, nor in a war which a king wages against his subjects. Thus Seneca distinguishes ‘wars declared upon neighbors, or waged with citizens.’

XII.     The effects referred to are not found in other wars.
What certain writers point out and teach by citing examples, to the effect that even in such wars what is seized belongs to those who take it, is indeed true, but only from one standpoint, that of the law of nature. It is not true by the customary law of nations, since this concerns nations only, not persons who have no existence as a nation or form a part of a nation.

The writers in question err in this also, that they think that a war undertaken for the defense of one’s person or property does not require a declaration. Such a war does require a declaration, not indeed of itself, but for the sake of those effects of which we have begun to speak, and which we shall shortly explain.

XIII.     Whether war may be waged simultaneously with its declaration.
This also is not true, that war cannot be waged at once upon being declared. That was the procedure of Cyrus against the Armenians, and of the Romans against the Carthaginians, as we have stated above. By the law of nations, in fact, no interval of time is required after the declaration. Nevertheless, it may happen that, from the character of the affair, by the law of nature some time may be required, as when restitution or punishment for a guilty person has been sought, and this has not been refused. In such a case time must be granted in order that, that which has been sought may be properly performed.

XIV.     Whether war must be declared against him who has violated the right of embassy.
Even if the right of embassy has been violated, there will not cease to be need of a declaration of war, for the sake of the effects of which I speak. However, it will be sufficient that this be made in a way in which it may be done with safety, as by means of writing, for example; for custom sanctions the use of writing for both summonses and other notices to be served in unsafe places.