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

Emmerich de Vattel

Of War, — its Different Kinds — and the Right of Making War

§ 1. Definition of war.1
WAR is that state in which we prosecute our right by force. We also understand, by this term, the act itself, or the manner of prosecuting our right by force: but it is more conformable to general usage, and more proper in a treatise on the law of war, to understand this term in the sense we have annexed to it.

§ 2. Public war.1
Public war is that which takes place between nations or sovereigns, and which is carried on in the name of the public power, and by its order. This is the war we are here to consider: — private war, or that which is carried on between private individuals, belongs to the law of nature properly so called.

§ 3. Right of making war.1
In treating of the right to security (Book 2, Chap. 4), we have shown that nature gives men a right to employ force, when it is necessary for their defense, and for the preservation of their rights. This principle is generally acknowledged: reason demonstrates it; and nature herself has engraved it on the heart of man. Some fanatics indeed, taking in a literal sense the moderation recommended in the gospel, have adopted the strange fancy of suffering themselves to be massacred or plundered, rather than oppose force to violence. But we need not fear that this error will make any great progress. The generality of mankind will, of themselves, guard against its contagion — happy, if they as well knew how to keep within the just bounds which nature has set to a right that is granted only through necessity! To mark those just bounds, — and, by the rules of justice, equity, and humanity, to moderate the exercise of that harsh, though too often necessary right — is the intention of this third book.

§ 4. It belongs only to the sovereign power.2
As nature has given men no right to employ force, unless when it becomes necessary for self defense and the preservation of their rights (Book II. § 49, etc.), the inference is manifest, that, since the establishment of political societies, a right, so dangerous in its exercise, no longer remains with private persons except in those encounters where society cannot protect or defend them. In the bosom of society, the public authority decides all the disputes of the citizens, represses violence, and checks every attempt to do ourselves justice with our own hands. If a private person intends to prosecute his right against the subject of a foreign power, he may apply to the sovereign of his adversary, or to the magistrates invested with the public authority: and if he is denied justice by them, he must have recourse to his own sovereign, who is obliged to protect him. It would be too dangerous to allow every citizen the liberty of doing himself justice against foreigners; as, in that case, there would not be a single member of the state who might not involve it in war. And how could peace be preserved between nations, if it were in the power of every private individual to disturb it? A right of so momentous a nature, — the right of judging whether the nation has real grounds of complaint, whether she is authorized to employ force, and justifiable in taking up arms, whether prudence will admit of such a step, and whether the welfare of the state requires it, — that right, I say, can belong only to the body of the nation, or to the sovereign, her representative. It is doubtless one of those rights, without which there can be no salutary government, and which are therefore called rights of majesty (Book I. § 45).

Thus the sovereign power alone is possessed of authority to make war. But, as the different rights which constitute this power, originally resident in the body of the nation, may be separated or limited according to the will of the nation (Book I. § 31 and 45), it is from the particular constitution of each state, that we are to learn where the power resides, that is authorized to make war in the name of the society at large. The kings of England, whose power is in other respects so limited, have the right of making war and peace.3 Those of Sweden have lost it. The brilliant but ruinous exploits of Charles XII. sufficiently warranted the states of that kingdom to reserve to themselves a right of such importance to their safety.

§ 5. Defensive and offensive war.
War is either defensive or offensive. He who takes up arms to repel the attack of an enemy, carries on a defensive war. He who is foremost in taking up arms, and attacks a nation that lived in peace with him, wages offensive war. The object of a defensive war is very simple; it is no other than self defense: in that of offensive war there is as great a variety as in the multifarious concerns of nations; but, in general, it relates either to the prosecution of some rights, or to safety. We attack a nation with a view either to obtain something to which we lay claim, to punish her for an injury she has done us, or to prevent one which she is preparing to do, and thus avert a danger with which she seems to threaten us. I do not here speak of the justice of war: — that shall make the subject of a particular chapter; — all I here propose is to indicate, in general, the various objects for which a nation takes up arms — objects which may furnish lawful reasons, or unjust pretenses, but which are at least susceptible of a color of right. I do not, therefore, among the objects of offensive war, set down conquest, or the desire of invading the property of others: views of that nature, destitute even of any reasonable pretext to countenance them, do not constitute the object of regular warfare, but of robbery, which we shall consider in its proper place.


     1.    See definition of war and of the king’s sole right to declare it, as regards England, per Sir Wm. Scott, The Hoop 1 Rob. R. 196; Nayade, 4 Rob. Rep. 252; Bro. Ab. tit. Denizen, pl. 20. and Chitty’s L.N. 28, 29, 30. — C.
     2.    The right of declaring war is, by his prerogative, vested in the king of the United Kingdom of Great Britain and Ireland. Bro. Ab. tit. Denizen, pl. 20. The ship Hoop, per Sir W. Scott, 1 Rob. R. 196, post, 432. — C. {And, by the Constitution of the United States, in Congress. Art. 1 § 8.}
     3.    I here speak of the right considered in itself. But as a king of England cannot, without the concurrence of parliament, either raise money or compel his subjects to take up arms, his right of making war is, in fact, but a slender prerogative, unless the parliament second him with supplies. — Ed. 1797.