Home  »  The Rights of War and Peace  »  Chapter III: On Just or Solemn War According to the Law of Nations on Declarations of War

Hugo Grotius (1583–1645). The Rights of War and Peace. 1901.

Book III

Chapter III: On Just or Solemn War According to the Law of Nations on Declarations of War

  • Solemn war, according to the Law of Nations between different states—A people, though engaged in unjust war, to be distinguished from pirates and robbers—Change in the condition of belligerents—Formal war can be made by the Sovereign power alone—Declaration of war—The Law of Nature, Law of Nations, respecting the same—Declaration, conditional, absolute—Forms of declaration introduced by the civil law—War declared against a Sovereign includes his subjects, and allies—The reason why allies are included—Declarations, why necessary to establish certain effects—Whether actual warfare immediately follows a declaration, considered—Whether the violation of an Ambassador’s rights to be a just ground of war.

  • I. IN the first book of this treatise it was observed, that according to the best writers, a war is defined to be just, not on account of the CAUSES solely, in which it originates, nor on account of the MAGNITUDE of its objects, but from certain, peculiar, effects of right, with which it is attended.

    But to what kind of war such an appellation most duly belongs will be best understood by considering the definition, which the Roman Lawyers have given of a PUBLIC or NATIONAL enemy. “Those says Pomponius, are PUBLIC and LAWFUL ENEMIES, with whose STATE our own is engaged in war: but enemies of every other description, come under the denomination of pirates and robbers. With that opinion Ulpian entirely accords, making an additional observation, that “if any one be taken by robbers, as he is not a lawful prisoner of war, he cannot claim of his own state the right of postliminium. But if he be taken prisoner by a public enemy of the state, being considered as a prisoner of war, he is entitled by the right of postliminium to be restored to his former condition.”

    These opinions are supported by that of Paulus, who maintains, that persons captured by pirates still continue free, that is, are not to be considered as prisoners, for whom an exchange may be demanded. So that by the opinion of the Roman Lawyers it is evident, that no war is considered to be lawful, regular, and formal, except that which is begun and carried on by the sovereign power of each country. Cicero, in his fourth Philippic, describes “a public and authorised enemy to be the person, who possesses the civil and military powers of the state, who can command the treasury, and the services of the people in support of his measures, and who, as occasions offer, has power to conclude treaties of peace and amity.”

    II. A state, though it may commit some act aggression, or injustice, does not thereby lose its political capacity, nor can a band of pirates or robbers ever become a state, although they may preserve among themselves that degree of subordination, which is absolutely necessary to the subsistence of all society. For with the latter, the commission of crime is the SOLE bond of union, whereas the former, though not always free from blame, but occasionally deviating from the laws of nature, which in many cases have been in a great measure obliterated, still regulate their conduct by the treaties, which they have made, and certain customs that have been established, being united among themselves for the mutual support of lawful rights, and connected with foreign states by known rules of standing polity.

    The Scholiast, upon Thucydides, remarks that the Greeks, at the time when piracy was reckoned lawful, forebore committing massacres, or nightly depredations, and carrying off the oxen that were necessary for the plough. We are informed by Strabo, that other nations too, who lived by plunder, after they had returned home from their predatory voyages, sent messages to the owners, whom they had plundered, to know if they would redeem the captures at a fair price.

    In morals, the whole system often derives its name from some one of the principal parts, as Cicero remarks, in the fifth book of his BOUNDS of GOOD and EVIL, and Galen observes that a mixture is often called by the name of its chief ingredient. So that Cicero is not altogether correct in saying, that a state is not merely diseased, but entirely destroyed, by the injustice of its component and leading members. For a morbid body is still a body, and a state, though dreadfully diseased, is still a political being, as long as its laws and tribunals and other necessary parts of its constitution remain, to administer justice and give redress to foreigners, no less than to private subjects in their actions against each other.

    There is a beautiful observation in Dion Chrysostom, who compares the law of a state, particularly that branch of it relating to the law of nations, to the body animated by the soul, upon the departure of which the corporeal frame becomes a mass of lifeless clay: in the same manner political society cannot subsist without the guiding and controuling principle of law. Aristides, encouraging the Rhodians to harmony, observes, that even under a tyrannical government many good laws may be found.

    These are points, which may be cleared up by examples. Thus Ulpian maintains that those who are captured by pirates cannot be considered as prisoners of war: but if captured by the Germans, for instance, or any national enemy, they lose their liberty for a time. But the Germans, as we are informed by Caesar, thought acts of plunder, if committed in a foreign territory, no disgrace. Tacitus says that the Cattians, a noble race of people in Germany, and the Garamantians were addicted to the same habits of plunder, yet still retained their rank among states.—Such is the difference between a national and political body, and a band of men uniting together SOLELY FOR THE COMMISSION OF CRIMES.

    III. A change may occur not only in the situations of individuals, as in those of Jephthah, Arsaces, and Viriatus, who, from being leaders of voluntary bands, became lawful commanders; but the same has also happened with respect to whole communities, which being originally composed of nothing but freebooters have, by the gradual course and changes of time, risen to the rank and dignity of states.

    IV. What has been said with respect to the right of making formal and lawful war, being vested in the sovereign power alone, includes those who have any share in the sovereign power, as the different communities forming the States General of many commonwealths. The same rule will hold good of those, who are not SUBJECTS of a superior state, but joined to it in confederacy by an unequal treaty: innumerable instances of which are to be found in history. This was the case between the Romans and their allies, the Volscians, the Latins, and the Spaniards: and all whom we read of being engaged in wars, which were considered as lawful and just.

    V. But to make a war just, according to this meaning, it must not only be carried on by the sovereign authority on both sides, but it must also be duly and formally declared, and declared in such a manner, as to be known to each of the belligerent powers. Cicero, in the first book of his offices, points out “the equity of the rules prescribed by the Roman Law for the declaration of war, from whence it may be concluded that no war is regular or just, but such as is undertaken to compel restitution, and to procure indemnity for injuries, and that too accompanied with a formal declaration.” Livy also in the same manner deems an observance of these rules requisite to form the characteristic of a just war. And describing an incursion of the Acarnanians into Attica, and their ravaging the country, he says that “those acts of irritation ended in a declaration of JUST and REGULAR war on both sides.”

    VI. In order to understand all these points clearly respecting the declaration of war, an accurate distinction must be made between the principles, which are founded on the law of nature itself, and those, which, though not derived immediately from that source, are still found to be just: it will be necessary also to examine, what is required by the law of nations towards obtaining, IN WAR, all the consequences, privileges and effects of that law, and at the same time, to investigate the consequences and rights arising from the peculiar laws and customs of particular nations.

    To repel force, or to punish a delinquent, the law of nature requires no declaration. And, as Thucydides relates, Sthenelaidas, one of the Ephori, maintains that “where we have been injured, not by WORDS, but by ACTIONS, the matter cannot be decided by WORDS and FORMS.” And Aelian, after Plato, observes that it is not the declaration of the Herald, but the voice and law of nature, which proclaim war, undertaken to repel force. Hence Dion Chrysostom, in addressing the Nicomedians, says that many wars are begun without any declaration.

    Upon the same ground Livy condemns the conduct of Menippus, a general belonging to Antiochus for having killed some Roman citizens before any declaration of war had been made, or even before a sword had been drawn, or a drop of blood spilt, to shew that hostilities were intended. By this objection he proves that either a formal declaration, or some act indicative of hostilities was deemed requisite to justify actual warfare.

    Neither, if we follow the law of nature, is there any more occasion for notice or declaration, where an owner intends to lay hands upon HIS OWN PROPERTY. But whenever one thing is taken in return for another, or the property of a debtor is seized for the recovery of a debt, and, especially, if any one intends seizing the property of those, who are subjects to the debtor, a formal demand must be made, as a proof that recourse to such security is the only means left to obtaining redress and satisfaction. Such a demand is necessary because that is not a PRIMARY and ORIGINAL right, but a SECONDARY right, SUBSTITUTED in the place of the primary and original, by the artificial rules of civil law.

    In the same manner to justify an attack upon a sovereign power for the aggressions and debts of its subjects, a previous remonstrance, and a proper demand of justice must be made to that power. For it is only by refusing to punish the guilty, or to grant indemnity to the injured, that states or sovereigns can be implicated in the misconduct of their subjects. But even where the law of nature does not directly prescribe that such a remonstrance or demand should be made, yet the common principles of humanity and equity will recommend the use of any means, that may prevent recourse to the calamities of war. The commandment given by God to the Hebrews, to send a message of peace to any state or city, before they began an intended attack, was designed as a special command to that people, yet some have confounded it with the general law of nations. For it was not ANY kind of peace that was meant by that injunction, but only such a peace as imposed terms of SUBJECTION and TRIBUTE. We are informed by Xenophon, that when Cyrus went into the country of the Armenians, he sent messengers to the king, to demand the tribute and number of troops, which had been stipulated by treaty.

    But to obtain the peculiar rights and consequences resulting from the law of nations, a declaration of war by one of the parties, at least, if not by both, is absolutely requisite in all cases.

    VII. Those declarations are either conditional or absolute. A conditional declaration is that which is coupled with a demand of restitution or redress. Under the name of restitution, the FECIAL LAW of Rome, that is the LAW RESPECTING DECLARATIONS OF WAR, comprehended not only the claims, which OWNERSHIP established, but the prosecution of EVERY right arising from criminal or civil causes.

    Hence the declarations were couched in terms, requiring restoration, satisfaction, or surrender. Here, by the term, surrender, the party appealed to is understood to have the option either of punishing the offender, himself, or delivering him up to the aggrieved person. This manner of demanding restitution is, according to the testimony of Pliny, called CLARIGATION, that is, a LOUD and FORMAL DEMAND. Livy gives us an example of a conditional and qualified declaration, wherein the aggrieved power denounces “a determined resolution to prosecute her rights with the utmost violence, if the agressor will not make reparation and atonement for the injury he has done.” Tacitus also relates the substance of a dispatch sent to Caecina by Germanicus, wherein he declares, that “if the ringleaders of the mutinous and rebellious legions are not immediately punished, he will advance with his army, and put the whole to the sword.”

    An ABSOLUTE declaration of war is issued, where any power has already begun hostilities, or committed acts which call for exemplary punishment. Sometimes indeed a conditional, is followed by an absolute war, though in such a case the latter is not actually necessary, but only a confirmation of the former. This gave rise to the form, which says, “an appeal is hereby made against such a people, as unjust and refusing to grant redress.” There is another form also purporting, that “the principal herald of the Roman citizens has made known to the principal herald of the ancient Latins, and to the Latin people, that redress is demanded of them by just and lawful war, on account of all the disputes which they have refused to settle, and the indemnities which they have been bound to grant, and have refused; and that this is the only means remaining to recover all that has been unjustly detained.” There is also a third mode of declaration, which runs in the following tenour; “Since the ancient people of the Latins have committed aggressions against the people of Rome, the people of Rome, with the advice and consent of the senate, declare war against them, and in the name of the senate and people of Rome their purpose is thus published.”

    But that in case of RENEWED wars such a declaration is not absolutely necessary, appears from the circumstance of its being made in due form at the nearest garrison, and not PERSONALLY to the offender himself, according to the answer given by the heralds, when they were consulted in the case of Philip of Macedon, and afterwards respecting Antiochus. Whereas a declaration for the FIRST time should be made to the enemy himself. Indeed in the war against Pyrrhus the declaration was made to one of his soldiers, in the Flaminian Circus, where, as Servius observes in his notes on the sixth book of the Aeneid, he was commanded to purchase a piece of ground, as a handle for dispute. A proof also that IN SOME CASES a declaration is superfluous may be taken from the circumstance that war is frequently declared by BOTH SIDES, which was done by the Corcyraeans and Corinthians in the Peloponnesian war, though a declaration by one of the parties would have been sufficient.

    VII. As to the use of the caduceum, or staff with the figure of two snakes twisted around it, which ambassadors carried, when they sued for peace, it was a ceremony peculiar to the GREEKS, and not derived from the GENERAL law of nations. The ROMANS in the same manner had particular customs, such as using vervain in forming alliances, throwing a bloody spear, as a declaration of war, renouncing all former friendship and alliance at the expiration of thirty days, after satisfaction had been demanded and refused, and again throwing another spear. None of these PECULIAR customs ought to be confounded with the GENERAL law of nations. For Arnobius informs us, that in his time many of them had fallen into disuse, and even in the time of Varro some of them were omitted. The third Punic war indeed was not declared till the moment of its actual commencement.

    IX. A declaration of war, made against a sovereign, includes not only his own subjects, but all who are likely to become his associates, as thereby they make themselves accessories in the war. And this is what the modern lawyers mean, when they say that, in bidding defiance to a Prince, we bid defiance to all his associates. For they give the name of defiance to a declaration of war. By which is understood the war carried on with the power against whom it has been declared. Thus upon war being declared against Antiochus, there was no occasion for a separate declaration against the Aetolians, who had openly joined Antiochus. For, as the heralds in their answer justly observed, the Aetolians had, by that act voluntarily brought war upon themselves.

    X. But if after the conclusion of such a war it should be deemed expedient to attack any other nation or king for having furnished supplies and assistance towards that war, a new declaration of war will be necessary. For that nation or king is then to be considered, not as an accessory, but as a principal enemy. And therefore it was with reason said, that the war of Manlius against the Galatians, and that of Caesar against Ariovistus, were not just wars according to the law of nations. For war was made upon them not as accessories, but as principals. So that for this purpose, as the law of nations would have required a declaration, in the same manner the Roman law would have required a new order of the Senate.

    For on the motion being made for the war with Antiochus, the question was also put, whether it should not at the same time be made with his adherents. The same rule also being observed against King Perseus, it must be understood, as including the adherents during all the time that war with those princes continued; and implicating all, who in reality gave them support.

    XI. The reason why a declaration is necessary to constitute what is deemed, according to the law of nations, a just war, is not that which some writers assign. For they allege that it is to prevent every appearance of clandestine and treacherous dealing: an openness, which may be dignified with the name of magnanimity, rather than entitled a matter of right. On this point, we are informed that some nations have gone so far, as to settle and make known the very time and place of a general engagement.

    But waving all conjecture, a more satisfactory reason may be found in the necessity that it should be known for CERTAIN, that a war is not the PRIVATE undertaking of bold ADVENTURERS, but made and sanctioned by the PUBLIC and SOVEREIGN authority on both sides; so that it is attended with the effects of binding all the subjects of the respective states;—and it is accompanied also with other consequences and rights, which do not belong to wars against pirates, and to civil wars.

    XII. There is much truth indeed in the observations, which some have made, and which they have produced examples to confirm, that even in wars of this kind all captures become the lawful prize of the captors.

    Yet this is only partially true, and that too, according to the law of nature, and not according to the voluntary law of nations. For the latter only makes provision to secure the rights of nations, as WHOLE communities, and not of those, who, as in civil wars, form but ONE PART of a nation.

    The same writers are mistaken too in the supposition that defensive wars require no declaration. For it is no less necessary to shew by way of vindication that it is a defensive war, and at the same time by public declaration to give it the character of a national and lawful war, in order to establish those rights and consequences, that have been already mentioned, and which will hereafter be more fully explained.

    XIII. They maintain another position also, which is by no means true, and that is, that a power ought not IMMEDIATELY to follow up a declaration of war with actual hostilities, as Cyrus did to the Armenians, and the Romans to the Carthaginians. For the law of nations requires the intervention of no DEFINITE time between the declaration and the commencement of war.

    There may indeed be some cases, where natural justice will render such a delay proper. Thus, for instance, where reparation for injury, or the punishment of aggressors is demanded, it is but reasonable to wait till it can be known, whether the just demand will be complied with or rejected.

    XIV. In order to establish the same consequences, a declaration will be equally necessary too, where the rights of Ambassadors have been violated. Yet it will be sufficient for it to be made in the manner, in which it may be done with the greatest safety. As in many other matters, in places which afford no security, satisfaction is demanded by denunciation or summons.