The Law of War and Peace (1625)

by Hugo Grotius

On The Causes of Undertaking War on Behalf of Others

I.     War may rightfully be undertaken on behalf of subjects.
1.   In the earlier part of this work, when we dealt with those who wage war, we asserted and showed that by the law of nature each individual was justified in enforcing not merely his own right but also that of another. The causes, therefore, which are just in relation to the person whose interest is at stake are just also in relation to those who give assistance to others.

2.   Now the first and particularly necessary concern is for subjects,’ either those who are subject to authority in a family, or those who are subject to a political authority. They are, in fact, as it were a part of the ruler, as we said in the same connection. For this reason, under the leadership of Joshua, the Jewish people took arms on behalf of the Gibeonites, who had submitted to them. ‘Our ancestors,’ said Cicero, addressing the Romans,’ often waged wars because their traders and sailors had been wrongfully treated.’ In another speech he said: ‘How many wars did our ancestors wage, because it was said that Roman citizens had been wronged, sailors detained, and traders robbed! ‘

The same Romans considered it necessary to take up arms on behalf of peoples who had surrendered (that is, had been made subjects), for whom they had refused to take up arms as allies. The Campanians declared to the Romans: ‘Even if you will not protect our interests with justifiable force against violence and wrong, you will surely defend your own.’ Florus says that the alliance formerly made by the Campanians was rendered more sacred by the surrender of all that was theirs.’ Good faith,’ said Livy,’ seemed to require that those who had surrendered should not be betrayed.’

II.     Yet war is not always to be undertaken on behalf of subjects.
Nevertheless, wars are not always to be waged on behalf of subjects even though the just cause of some subject places the ruler under obligation to undertake them. Such wars are to be undertaken only when this can be done without loss to all the subjects, or to the majority of them. The duty of the ruler concerns the whole rather than parts; and the greater a part is, the more nearly it approaches the character of the whole.

III.     Whether an innocent subject may be surrendered to an enemy, in order that danger may be avoided.
1.   Thus if one citizen, although innocent, is demanded by an enemy, to be made away with, there is no doubt that he may be abandoned to them’ if it appears that the state is by no means a match for the power of the enemy.

This view is opposed by Fernando Vazquez; but, if you consider his purpose rather than his words, he seems to be making this point, that such a citizen is not to be hastily abandoned, where there is hope that he may be defended. For he also cites the story of the Italian infantry who deserted Pompey when his cause was not yet clearly desperate, but when they had been assured of their safety by Caesar. This conduct he deservedly censures.

2.   Still the learned do discuss the question whether an innocent citizen may be delivered into the hands of the enemy, in order to prevent the ruin otherwise threatening the state; and the same question was debated long ago, as when Demosthenes brought forward the notable fable of the dogs, which the wolves demanded should be surrendered to them by the sheep for the sake of peace. That such a surrender may be made is denied not merely by Vazquez but also by Soto, whose opinion is attacked by Vazquez as bordering on treachery. Nevertheless, Soto holds that such a citizen is bound to surrender himself to the enemy; but this also is denied by Vazquez, on the ground that the nature of political society, which each enters for his own advantage, does not require it.

3.   But from this nothing more follows than that a citizen is not bound to surrender himself by law properly so called; it does not follow also that love permits him to do otherwise. For there are many duties which are not in the domain of justice properly speaking, but in that of affection, which are not only discharged amid praise (this Vazquez does not recognize) but cannot even be omitted without blame.

Such a duty seems quite clearly to be this, that a person should value the lives of a very large number of innocent persons above his own life. Praxithea in the Erechtheus of Euripides says:

      For if I numbers know and from the less
      The greater can distinguish, then the ill
      That but one house afflicts is less by far
      Than that of a whole city, nor with this compares.

Thus Phocion used to urge Demosthenes and others, after the example of the daughters of Leos and Hyacinthus,” to die themselves rather than to permit an incurable evil to be inflicted on their country.

In his speech For Publius Sestius Cicero said:

If it had befallen me, when sailing with my friends on board some vessel, that from many directions many pirates threatened to attack the ship with their fleets unless my friends should have surrendered me alone to them, and if the voyagers refused to do this, and preferred to perish with me, rather than surrender me to my enemies, I would rather have cast myself into the deep, in order to save the rest, than bring to certain death, or even into great risk of their lives, those who loved me so well.

The same author in the third book On Ends says: ‘A man who, is, good and wise and obedient to the laws, and who understands the duty of a citizen, consults the interest of all rather than of any single; individual or of himself.’ In Livy we read in regard to certain’ Molossians: ‘I have often heard tales of those who sought death for their country’s sake; but these are the first yet found who thought’ it right that their country should perish for them.’

4.   But on the supposition that a citizen demanded by the enemy ought to surrender himself to them there remains the question whether he may be compelled to do that to which he is morally bound. Soto declares that he cannot, and by way of illustration cites the case of the rich man who by the precepts of mercy is bound to give alms to the poor man, but who nevertheless cannot be forced to do so, We must observe, however, that the relation of parts among themselves is one thing, and that of superiors, when they are contrasted with those subject to them, is quite another. For an equal cannot be compelled by an equal, except to perform what is owed in accordance with a right properly so called. But a superior can compel an inferior to do other things also, which some virtue demands, because this is embraced in the proper right of the superior as such. Thus during a grain famine citizens may be compelled to contribute what they have to the common store.

Hence in this argument of ours it seems even more true that a citizen may be constrained to do that which regard for others; requires. Thus Phocion, whom I have just mentioned, pointing out a certain man, Nicocles by name, who was a very great friend of his, said that such a climax of evils had been reached that, if Alexander, should demand Nicocles, he himself should vote that Nicocles should, be surrendered.

IV.     Wars may rightfully be undertaken also on behalf of allies of equal or unequal standing.
Next to subjects, and indeed on an equal footing with them in this respect, that they ought to be defended, are allies, in whose treaty of alliance this obligation is embraced, whether they have surrendered themselves to the guardianship and good faith of others, or have agreed to give and receive mutual assistance. ‘He who does not protect an ally from wrong, when he can do so, is at fault, just as he who does the wrong,’ says Ambrose.

We have said elsewhere, however, that such agreements cannot be stretched to include wars for which no just cause exists. This in truth is the reason why the Lacedaemonians, before they made war upon the Athenians, permitted all their allies to pass judgement upon the justice of the cause; and it was for that reason that the Romans allowed the Greeks to pass judgement on the war against Nabis. We may now add this principle, that not even under such conditions is an ally bound to render aid if there is no hope of a successful issue. The reason is that an alliance is formed for the take of good, and not of ill. However, an ally is to be protected even against another ally that is in alliance on the same terms, unless in the previous treaty there is some particular provision to the contrary. Thus the Athenians were able to defend the Corcyreans, provided that the cause of the latter was just, even against the Corinthians, who had been their allies for a longer time.

V.     Wars may rightfully be undertaken on behalf of friends.
The third cause for undertaking wars on behalf of others is obligation to friends, to whom aid has not been promised, to be sure, but yet is owed under a certain principle of friendship, if it can be rendered easily and without loss. For such a reason Abraham took up. arms in behalf of his kinsman Lot; on such grounds the Romans forbade the people of Antium to practice piracy upon the Greeks, alleging that the Greeks were related to the Italians. The Romans also frequently waged wars, or threatened to wage war, not only on behalf of their allies, to whom they owed this obligation in accordance with a treaty, but also on behalf of their friends.

VI.     Wars, finally, may rightfully be undertaken on behalf of any persons whatsoever.
The final and most wide-reaching cause for undertaking wars on behalf of others is the mutual tie of kinship among men, which of itself affords sufficient ground for rendering assistance. ‘Men have been born to aid one another,’ says Seneca. From the same author come the words: ‘The wise man, whenever he shall be able, will interpose between fortune and fortune’s victims.’ In his Suppliants Euripides says:

      The rocks afford a refuge for wild beasts,
      And altars protect slaves, but cities crushed with ills
      In other towns their bulwark find.

In the view of Ambrose: ‘Courage which defends the weak is perfect justice.’ This point also we have previously discussed.

VII.     Nevertheless the obligation to undertake war may be disregarded without wrong, if one fears for himself, or even for the life of an innocent person.
1.   At this point the question arises, whether a man is bound to defend a man, or one people another people, from wrong. Plato thinks that he who does not defend another from violence should be'” punished; and this was provided for even in the laws of the’ Egyptians. But first, if danger is evident, it is certain that a man is not so bound, for he may prefer his own life and interests to those of others. In this sense I think we must interpret the words of Cicero: ‘He who does not prevent or oppose a wrong, if he can, is as much at fault as if he should desert his parents, or country, or associates.’ The word ‘can’ we may understand as ‘with advantage to himself’; for the same author says also in another place: ‘Perhaps men cannot be defended without incurring censure.’

In the histories of Sallust we find the following: ‘All men who, when their affairs are prosperous, are besought to join an alliance for war, ought to reflect whether they may at that time maintain peace; then whether what is asked of them is sufficiently blameless, safe, glorious, or dishonorable.’

2.   This statement of Seneca also should not be scorned: ‘I shall come to the aid of the perishing, but in such a way that I myself may not perish, unless I am to be the price of a great man or a great cause.’ But not even in the latter case will a man be obliged too render aid if the person oppressed cannot be delivered save by the death of the oppressor. For if the person who is attacked can put the life of the aggressor above his own, as we have said elsewhere, he will not do wrong who either believes or desires that the person attacked may prefer this also; especially when in the case of the aggressor there is the greater danger of irremedial and eternal loss.

VIII.     The question whether a war for the defense of subjects of another power is rightful is explained by a distinction.
1.   This too is a matter of controversy, whether there may be just cause for undertaking war on behalf of the subjects of another ruler, in order to protect them from wrong at his hands. Now it is certain that, from the time when political associations were formed, each of their rulers has sought to assert some particular right over his own subjects. As we see in the Children of Hercules, by Euripides:

      Just are we who within our city dwell,
      And judgment we may render with full power.

Here too applies the following:

      Sparta, which is thy lot, adorn;
      We for Mycenae shall have care.

Among the signs of supreme power Thucydides reckoned ‘having their own courts of justice’ no less than ‘the right to make their own laws and levy taxes.’ Akin is the thought of the poet:

      Not to him but to me by lot was given
      The rule of the sea and the trident’s realm.

Quite similar is the following:

      To the gods is it never permitted
      The acts of the gods to revoke.

In Euripides we find this:

      Among the gods the usage fixed is this
      ‘Tis wrong for one to thwart the other’s will.

The purpose no doubt is, as Ambrose correctly explains, ‘to prevent men from provoking wars by usurping the care for things under the control of others.’

In Thucydides the Corinthians find it just that’ each party should punish its own subjects.” Perseus, in his speech to Marcius, refused to present a defense of his conduct toward the Dollops, saying: ‘I have acted by virtue of my right, since they belonged to my kingdom and were subject to my authority.’ But all these rights have force in cases where subjects are actually in the wrong, and also, you may add, where the cause is doubtful. For such purposes in fact this division of authorities was established.

2.   If, however, the wrong is obvious, in case some Busiris, Phalaris, or Thracian Diomede should inflict upon his subjects such treatment as no one is warranted in inflicting, the exercise of the right vested in human society is not precluded. In conformity with this principle Constantine took up arms against Maxentius and Licinius, and other Roman emperors either took up arms against the Persians,.’ or threatened to do so, unless these should check their persecutions of the Christians on account of religion.

3.   If, further, it should be granted that even in extreme need subjects cannot justifiably take up arms (on this point we have seen that those very persons whose purpose was to defend the royal power are in doubt), nevertheless it will not follow that others may not take up arms on their behalf. For whenever the check imposed upon some action arises from the person concerned and not the action itself, then what is refused to one may be permitted to another on his behalf, provided that the matter is such that the one may therein be of service to the other.

Thus a guardian, or some other person, goes to law on behalf of a pupil, who is personally incapable of legal action; and counsel may, appear for one who is absent, even without authority. The restriction, in fact, which prevents a subject from resisting, does not arise from a cause which is identical in the case of a subject and of one who’ is not a subject, but from the personal condition which is not transferred to others.

4.   Hence, Seneca thinks that I may make war upon one who is not one of my people but oppresses his own, as we said when dealing with the infliction of punishment; a procedure which is often connected with the protection of innocent persons. We know, it is true, from both ancient and modern history, that the desire for what is another’s seeks such pretexts as this for its own ends; but a right does not at once cease to exist in case it is to some extent abused by evil men. Pirates, also, sail the sea; arms are carried also by brigands;

IX. Military alliances and mercenary service without dissemination regarding the causes of f war are unjust.
1.   Again, just as military alliances, which were entered into with the intention that aid should be rendered for any sort of war without distinction of cause,’ are not permissible, as we have said, so no manner of life is more wicked than that of those who serve as soldiers for hire without regard to the cause of hostilities, and for whom

      Where greatest profit is, there too is right.

This Plato shows from the example of Tyrtaeus.

Such conduct, we read, was censured in the Aetolians by Philip; and in the case of the Arcadians by Dionysius of Miletus, with these words: ‘The market for soldiery is open, and the ills of the Greeks nourish the land of the Arcadians, while men under arms go hither and thither without giving any consideration to the cause.’ Truly a wretched thing, as Antiphanes says, is

      The soldier who, to maintain life, hires himself to death.’

Dio of Prusa says: ‘What is more necessary for us than life, or what is accounted of greater value? Yet even this not a few lose through quest of gain.’

2.   It would in truth matter little that mercenaries sell their own lives, if they did not sell also the lives of others, who are often innocent. In this respect they are much more abominable than an executioner, in the degree that it is worse to slay without cause than with cause. So Antisthenes used to say that executioners are more free from guilt than tyrants, because they execute criminals, while tyrants slay those who are innocent. Philip the Elder of Macedon said that to men of this type, ‘whose livelihood comes solely from mercenary service,’ war was peace and peace was war.

3.   Warfare has no place among the useful arts. Nay, rather, it is so horrible that only the utmost necessity, or true affection, can render it honorable. How this is possible may be gathered from what we have said in the last of the preceding chapters. In the opinion of Augustine,’ to serve as a soldier is no crime: but to do so for the sake of plunder is a sin.’

X.     It is also particularly wrong to take service merely for the sake of plunder or pay.
The same principle applies in the case of military service for pay, if this is the sole or chief aim in view.

On other grounds it is altogether permissible to receive pay. ‘What soldier ever serveth at his own charges?’ says the Apostle Paul.