The mode

of England would have been too evident to render a statement of it necessary. But this was not the only case to which the treaties were applicable. If troops were assembled, and preparations made, with the manifest purpose of aggression against an ally; if his subjects were instigated to revolt, and his soldiers to mutiny; if insurgents on his territory were supplied with money, with arms, and military stores: if, at the same time, his authority were treated as a usurpation, all participation in the protection granted to other foreigners refused to the well-affected part of his subjects, while those who proclaimed their hostility to his person were received as the most favoured strangers;-in such a combination of circumstances, it could not be doubted that the case foreseen by defensive alliances would arise, and that he would be entitled to claim that succour, either general or specific, for which his alliances had stipulated. The wrong would be as complete, and the danger might be as great, as if his territory were invaded by a foreign force. chosen by his enemy might even be more effectual, and more certainly destructive, than open war. Whether the attack made on him be open or secret, if it be equally unjust, and exposes him to the same peril, he is equally authorized to call for aid. All contracts, under the law of nations, are interpreted as extending to every case manifestly and certainly parallel to those cases for which they provide by express words. In that law, which has no tribunal but the conscience of mankind, there is no distinction between the evasion and the violation of a contract. It requires aid against disguised as much as against avowed injustice; and it does not fall into so gross an absurdity as to make the obligation to succour less where the danger is greater. The only rule for the interpretation of defensive alliances seems to be, that every wrong which gives to one ally a just cause of war, entitles him to succour from the other ally. The right to aid is a secondary right, incident to that of repelling injustice by force. Wherever he may morally employ his own strength for that purpose, he may with reason demand the auxiliary

strength of his ally.19 Fraud neither gives nor takes away any right. Had France, in the year 1715, assembled squadrons in her harbours and troops on her coasts; had she prompted and distributed writings against the legitimate government of George I.; had she received with open arms battalions of deserters from his troops, and furnished the army of the earl of Mar with pay and arms when he proclaimed the pretender; Great Britain, after demand and refusal of reparation, would have had a perfect right to declare war against France, and, consequently, as complete a title to the succour which the StatesGeneral were bound to furnish by their treaties of alliance and guarantee of the succession of the house of Hanover, as if the pretended king, James III., at the head of the French army, were marching on London. The war would be equally defensive on the part of England, and the obligation equally incumbent on Holland. It would show a more than ordinary defect of understanding to confound a war defensive in its principles with a war defensive in its operations. Where attack is the best mode of providing for the defence of a state, the war is defensive in principle, though the operations are offensive. Where the war is unnecessary to safety, its of fensive character is not altered, because the wrong-doer is reduced to defensive warfare. So a state, against which dangerous wrong is manifestly meditated, may prevent it by striking the first blow, without thereby waging a war in its principle offensive. Accordingly, it is not every attack made on a state that will entitle it to aid under a defensive alliance; for if that state had given just cause of war to the invader, the war would not be on its part defensive in principle.20

19 Vattel's reasoning is still more conclusive in a case of guarantee:"Si l'alliance défensive porte un garantie de toutes les terres que l'allié possède actuellement, le casus fœderis se deploie toutes les fois que ces terres sont envahiés ou menaçées d'invasion.”—Liv. îii, ch. 6, § 91.

20 ❝ Dans une alliance défensive le casus fœderis n'existe pas tout de suite que notre allié est attaqué. Il faut voir s'il n'a point donné à son ennemie un juste sujet de lui faire la guerre. S'il est dans le tort, il faut l'engager à donner une satisfaction raisonable."-Vattel, liv. iii. ch. 6, § 90.

1

$14.

Hostages

The execution of a treaty is sometimes secured by hostages for the ex- given by one party to the other. The most recent and reecution of markable example of this practice occurred at the peace of

treaties.

§ 15.

tation of treaties.

Aix-la-Chapelle, in 1748, where the restitution of Cape Breton in North America, by Great Britain to France, was secured by several British peers sent as hostages to Paris.21

Public treaties are to be interpreted like municipal laws Interpre- and private contracts. Such is the inevitable imperfection and ambiguity of all human language, that the mere words alone of any writing, literally expounded, will go a very little way towards explaining its meaning. Certain technical rules of interpretation have therefore been adopted by writers on ethics and public law, to explain the meaning of international compacts in cases of doubt. These rules are fully expounded by Grotius and his commentators, and the reader is referred especially to the principles laid down by Vattel and Rutherforth, as containing the completest view of this important subject.22

§ 16.

Negotiations are sometimes conducted under the mediation Mediation. of a third power, spontaneously tendering its good offices for this purpose, or upon the request of one or both of the litigating powers, or in virtue of a previous stipulation for that purpose. If the mediation is spontaneously offered, it may be refused by either party: but if it is the result of a previous agreement between the two parties, it cannot be refused without a breach of good faith. When accepted by both parties, it becomes the right and the duty of the mediating power to interpose its advice, with a view to the adjustment of their differences. It thus becomes a party to the negotiation, but has no authority to constrain either party to adopt its opinion. Nor is it obliged to guaranty the performance

21 Vattel, liv. ii. ch. 16, §§ 245-261.

22 Grotius, de Jur. Bel. ac Pac. lib. ii. cap. 16. Vattel, liv. ii. ch. 17. Rutherforth's Inst. b. ii. ch. 7.

of the treaty concluded under its mediation, though, in point of fact, it frequently does so.23

The art of negotiation seems, from its very nature, hardly $17. Diplomacapable of being reduced to a systematic science. It depends tic history. essentially on personal character and qualities, united with a knowledge of the world and experience in business. These talents may be strengthened by the study of history, and especially the history of diplomatic negotiations; but the want of them can hardly be supplied by any knowledge derived merely from books. One of the earliest works of this kind is that commonly called Le Parfait Ambassadeur, originally published in Spanish by Don Antonio de Vera, long time ambassador of Spain at Venice, who died in 1658. It was subsequently published by the author in Latin, and different translations appeared in Italian and French. Wicquefort's book, published in 1679, under the title of L'Ambassadeur et ses Fonctions, although its principal object is to treat of the rights of legation, contains much valuable information upon the art of negotiation. Callieres, one of the French plenipotentiaries at the treaty of Ryswick, published in 1716 a work entitled De la Manière de Negocier avec les Souverains, which obtained considerable reputation. The Abbé Mably also attempted to treat this subject systematically, in an essay entitled Principes des Negotiations, which is commonly prefixed as an introduction to his Droit Publique de l'Europe in the various editions of the works of that author. A catalogue of the different histories which have appeared of particular negotiations would be almost interminable, but nearly all that is valuable in them will be found collected in the excellent work of M. Flassan, entitled L'Histoire de la Diplomatie Française. The late Count de Ségur's compilation from the papers of Favier, one of the principal secret agents employed in the double diplomacy of Louis XV., entitled Politique de tous les Cabinets de l'Europe pendant les Règnes de Louis XV. et de

23 Kluber, Droit des Gens Moderne de l'Europe, pt. ii. tit. 2, § 1; ch. 2, § 160.

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Louis XVI., with the notes of the able and experienced editor, is a work which also throws great light upon the history of French diplomacy. A history of treaties from the earliest times to the emperor Charlemagne, collected from the ancient Latin and Greek authors, and from other monuments of antiquity, was published by Barbeyrac in 1739. It had been preceded by the immense collection of Dumont, embracing all the public treaties of Europe from the age of Charlemagne to the commencement of the eighteenth century.24 The best collections of the more modern European treaties are those published at different periods by Professor Martens, of Göttingen, including the most important public acts upon which the present conventional law of Europe is founded. To these may be added Koch's Histoire abregée des Traités de Paix depuis la Paix de Westphalie, continued by Schöll. A complete collection of the proceedings of the congress of Vienna has also been published in German, by Kluber.25

24 Corps Universel Diplomatique du Droit des Gens, &c. 8 tomes fol. Amsterd. 1726-1731. Supplement au Corps Universel Diplomatique, 5 tomes fol. 1739.

25 Acten des Wiener Congresses in den Jahren, 1814 und 1815; von J. L. Kluber, Erlangen, 1815 und 1816; 6 Bde. 8vo.