refuse to render the promised assistance, for the tacit condition on which such assistance was stipulated to be given has not been observed, or, in other words, the casus foederis has not taken place.

§ 10. If, on the contrary, a party to the defensive alliance, could call upon his ally to assist him whenever he was assailed, and without regard to the justice of the war, or the circumstances of the attack, there would be no difference between a defensive and an offensive alliance, for, as stated in the chapter on different kinds of war, many wars which are defensive in their operations are essentially offensive in their character and principles. In the words of Wheaton, '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 offensive character is not altered, because the wrong-doer is reduced to defensive warfare. So, a State, against which a 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.' 1

§ II. Admitting the principle laid down by Vattel, that every treaty of alliance contains the tacit clause that it shall not be binding, except in case of a just war, and that the coally has a right to decide for himself upon the character of the war, and whether or not the casus foederis has taken place, it is only in case the war is clearly and obviously unjust that he can claim a release from the obligations which he voluntarily contracted. Whether the alliance be offensive or defensive, or both, if there be strong reasons to doubt the justice of the war, the ally is to be allowed time to examine it before he can be required to render the stipulated assistance; but, unless upon such examination, he find it manifestly unjust, he must comply with his engagements. Under ordinary circumstances, and in the absence of any proof to the contrary, he is bound to consider that his co-ally has just cause of war. In speak

1 Wildman, Int. Law, vol. ii. p. 166; Grotius, de Fur. Bel. ac Pa., lib. ii. cap. xv. § 13; Garden, De Diplomatie, liv. vi. sec. ii. § 2; Burlamaqui, Droit de la Nat. et des Gens, tome v. pt. iv. ch. iii.

ing of the tacit restriction, which Vattel says is necessarily understood in every treaty of alliance, Mr. Wheaton remarks that it can be applied only to a manifest case of unjust aggression on the part of the other contracting party, and cannot be used as a pretext to elude the performance of a positive and unequivocal engagement, without justly exposing the ally to the imputation of bad faith. In doubtful cases, the presumption ought rather to be in favour of our confederate, and of the justice of his quarrel.''

§ 12. We have already pointed out the distinction between treaties of alliance and treaties of limited succour and subsidy. In a treaty of succour, the ally stipulates to furnish certain assistance in troops, ships of war, provisions, or money. If the succour is to consist of troops, they are called auxiliaries; if of money, it is called subsidy. The rules already laid down, with respect to the casus foederis in treaties of alliance made before the war, apply equally to treaties of limited succour and subsidy. For the reasons there given, such treaties are not binding where the war is manifestly unjust.

§ 13. Again, Vattel says that if the State which has promised succour finds itself unable to furnish it, this inability alone is sufficient to dispense with the obligation. If, for example, one of the allies is engaged in another war, not contemplated by the alliance, and which requires his whole strength, he is absolved from sending assistance to his ally in the war to which he is not yet a party. Again, if he has promised provisions, and his own subjects are suffering from famine, the casus foederis does not take effect; for he is not obliged to give another what is absolutely necessary for the use of his own people. It seems to us that a promise is none the less binding because of the inability of the promisor to fulfil his engagements.2

§ 14. It is also proper to remark that even where the casus foederis is admitted to take place, and the stipulated succours are furnished, the ally who furnishes them is not necessarily made a party to the war. 'Where one State,' says Wheaton,

1 Vattel, Droit des Gens, liv. ii. ch. x. § 90, and liv. iii. ch. vi. §§ 79–82; Wheaton, Elem. Int. Law, pt. iii. ch. ii. § 15; Bynkershoek, Quaest Fur. Pub., ib. i. cap. ix.; Bello, Derecho Internacional, pt. ii. cap. ix. § I. Vattel, Droit des Gens, liv. iii. ch. vi. §§ 81, 92; Wheaton, Elem. Int. Law, pt. iii. ch. ii. §§ 14, 15; De Felice, Droit de la Nat. et des Gens, tome

2

ii. lec. 28.

'stipulates to furnish to another a limited succour of troops, ships of war, money, or provisions, without any promise looking to an eventual engagement in general hostilities, such a treaty does not necessarily render the party furnishing this limited succour the enemy of the opposite belligerent. It only becomes such, so far as respects the auxiliary forces thus supplied; in all other respects it remains neutral. Such, for example, have long been the accustomed relations of the confederated cantons of Switzerland with the other European powers."1

§ 15. A distinction, however, must be made between simple treaties of succour and subsidy, and capitulations for mercenaries, like those formerly entered into by the Swiss. Auxiliary troops are usually under the general control and direction of the power which furnishes them, and which is, therefore, in a measure, responsible for their acts. But mercenaries, furnished under capitulations, usually engage in a foreign service for a stated period, and for stipulated pay and allowances, being entirely at the disposition of the power which employs them, that which furnishes them having no part in the conquests which are made, or in the negotiations and treaties which are entered into.2

§ 16. Vattel discusses the question, whether the limited

1 Vattel, liv. 3, ch. 6, §§ 79, 82; Riquelme, Derecho Pub. Int., lib. i. tit. i. cap. xii.; Bello, Derecho Internacional, pt. ii. cap. ix. § 1.

But in 1859, the Federal Government passed a law-(1.) forbidding any Swiss citizen to enroll himself, as soldier to a foreign State, without the permission of the Government of his Canton, (2.) enacting severe penalties, against whosoever might seek to recruit, (3.) forbidding any Swiss citizen to take service in a foreign country, in a corps, not making part of the national army, of that State for which he was enrolled, (4) forbidding any Swiss citizen to engage himself to form a corps composed in whole, or in part, of Swiss citizens, for any State; and, on the other hand, prohibiting foreigners to enroll Swiss citizens, or to assist therein.

The Neapolitan Government had some regiments, composed entirely of Swiss soldiers, by virtue of a capitulation, which ended the 15th of June, 1859. In that year, a mutiny broke out among these troops; 300 were shot down by the Neapolitan soldiers, and the remainder were sent back to Switzerland. This occurrence, together with some questions which arose the same year, concerning the employment of Swiss soldiers in foreign States, and especially in Italy, was the immediate cause of the passing of the above-mentioned law.

Swiss troops were, and still are, in the Papal service, but without any capitulation. (Annuaire Historique, 1859.)

2 Martens, Précis du Droit des Gens, §§ 301-3; Galiani, Dei Doveri dei Prin., &c. lib. i. cap. v. p. 145; Moser, Versuch, &c. b. x. pt. i. pp. 139, 140; Romainmatier, Histoire Militaire des Suisse, passim; Garden, De Diplomatie, liv. vi. sec. ii. § 2.

assistance rendered to the enemy, under the obligations of a subsidy-treaty, is a just cause of war. If the ally of our enemy, he says, goes no further than to furnish the stipulated succour, and, in other respects, preserves toward us the accustomed relations of friendship and neutrality, we may overlook this cause of complaint. This prudent caution of avoiding an open rupture with those who render to our enemy certain limited assistance, previously stipulated for, has gradually introduced the custom of not regarding it as an act of hostility, especially where it is of a limited character. But, if prudence dissuades us from making use of a right, it does not thereby destroy the right itself. A cautious belligerent may choose to overlook certain offences, rather than unnecessarily increase the number of its enemies, and be influenced by considerations of expediency, in not enforcing the strict rights of war. It is, therefore, a question of policy, whether the assistance furnished an enemy shall be regarded as good and sufficient cause for declaring war against the ally who furnishes it.'

§ 17. We have described, in another chapter, the general character of treaties of guarantee and surety, as distinguished from ordinary treaties of alliance. The question to be considered here is, how far such treaties bind the party making the guarantee to assist the other party in a war for the defence or the security of the thing guaranteed? For example, Great Britain, by the treaties of 1642, 1654, 1661, 1703, 1807, 1810, and 1815, with Portugal, guaranteed the latter kingdom to the lawful heir of the house of Bragansa, and agreed to defend it against every hostile attack.' In the case of a war between Portugal and a third power, in which the former was subjected to 'a hostile attack,' was Great Britain bound to join in the war, without regard to its justice or injustice? Some publicists have laid down the general rule, that where one of the allies has guaranteed to the other certain specified rights or possessions, which are taken away or seized by a third power, this third power places itself in a position of hostility towards both of the contracting parties. In this case, it is said, the guaranteeing party cannot refuse to succour his ally. Here his duty is plain and indisputable, and if he should

1 Vattel, Droit des Gens, liv. iii. ch. vi. §§ 79-82; Wheaton, Elem. Int. Law, pt. iii. ch. ii. § 14; Heffter, Droit International, §§ 115-7.

refuse to take part in the war, he is justly chargeable with a breach of the alliance. The casus foederis takes place, it is said, as soon as the rights or possessions so guaranteed are seized or encroached upon. The agreement, being for the security of a specific right, or the possession of a particular territory, it is special, and the covenant cannot be evaded or avoided by any general plea of the injustice of the war. Others say that treaties of guarantee are of the nature of a defensive alliance; and, consequently, that even where territories are guaranteed, the guarantee does not extend to wars provoked by the aggression of the party guaranteed. If, therefore, the war be manifestly unjust on the part of the ally so guaranteed, the casus foederis does not take place, and the stipulation is not binding. This view is consonant with general principles; for if the war be morally wrong on the part of one ally, he cannot reasonably demand the auxiliary strength of his co-ally to assist him in its prosecution. Again, in the case of the guarantee of a treaty, it is said that the guarantee is not only not obliged, but is not even authorised to interfere to compel its performance, unless required to do so by a party guaranteed, because the contracting parties are at liberty to vary its stipulations, or dispense altogether with their performance. It follows, therefore, that a party to a treaty of guarantee is not necessarily a party to a war undertaken by his co-ally, even though it be in defence of the thing guaranteed.1

§ 18. Conflicts not unfrequently occur in warlike alliances. In the case of an alliance for war, made towards and against all, with the reservation of allies, this exception is to be understood to include present allies only, and not to extend to any subsequent treaty stipulations with other powers. Vattel supposes this case: 'Three powers have entered into a treaty

1 Bello, Derecho Internacional, pt. ii. cap. ix. § 1.

In 1826, the Princess Regent of Portugal required the assistance of Great Britain against Spain, by virtue of the tripartite treaty of 1703 between England, Portugal, and Holland; Mr. Canning argued in the House of Commons that it was necessary to show that a casus foederis had arisen, although the existence of the treaty was not denied. It may be questioned whether, even where a casus foederis be made out, a State be bound to interfere in the quarrel without inquiring into the merits of the cause. See case of Charles et Georges, State Papers, 1859.

A treaty expires if one of the contracting parties should lose its existence, as was the case in the dissolution of Poland, 1795.