§ 359. Violations of neutrality, whether committed by a neutral against a belligerent or by a belligerent against a neutral, are international delinquencies.[708] They may at once be repulsed, the offended party may require the offender to make reparation, and, if this is refused, it may take such measures as it thinks adequate to exact the necessary reparation.[709] If the violation is only slight and unimportant, the offended State will often merely complain. If, on the other hand, the violation is very substantial and grave, the offended State will perhaps at once declare that it considers itself at war with the offender. In such case it is not the violation of neutrality which brings neutrality to an end, but the declaration of the offended State that it considers the violation of so grave a character as to oblige it to regard itself at war with the offender.
[708] See above, [vol. I. § 151].
[709] See above, [vol. I. § 156].
That a violation of neutrality can only, like any other international delinquency, be committed by malice or culpable negligence,[710] and that it can be committed through a State's refusing to comply with the consequences of its "vicarious" responsibility for acts of its agents or subjects,[711] is a matter of course. Thus, if a belligerent fleet attacks enemy vessels in neutral territorial waters without an order from its Government, the latter bears "vicarious" responsibility for this violation of neutral territory on the part of its fleet. If the Government concerned refuses to disown the act of its fleet and to make the necessary reparation, this "vicarious" responsibility turns into "original" responsibility, for a case of violation of neutrality and an international delinquency has then arisen. And the same is valid if an agent of a neutral State without an order of his Government commits such an act as would constitute a violation of neutrality in case it were ordered by the Government; for instance, if the head of a province of a neutral, without thereto being authorised by his Government, allows forces of a belligerent to march through this neutral territory.
[710] See above, [vol. I. § 154].
[711] See above, [vol. I. § 150].
Neutrals not to acquiesce in Violations of Neutrality committed by a Belligerent.
§ 360. It is entirely within the discretion of a belligerent whether he will acquiesce in a violation of neutrality committed by a neutral in favour of the other belligerent. On the other hand, a neutral may not exercise the same discretion regarding a violation of neutrality committed by one belligerent and detrimental to the other. His duty of impartiality rather obliges him in the first instance to prevent, with the means at his disposal, the belligerent concerned from committing such violation; for instance, to repulse an attack of men-of-war of a belligerent on enemy vessels in neutral ports. Thus article 3 of Convention XIII. enacts:—"When a ship has been captured in the territorial waters of a neutral Power, such Power must, if the prize is still within its jurisdiction, employ the means at its disposal to release the prize with its officers and crew, and to intern the prize crew." And in case he could not prevent and repulse a violation of his neutrality, the same duty obliges him to exact due reparation from the offender,[712] for otherwise he would favour the one party to the detriment of the other. If a neutral neglects this obligation, he is thereby committing a violation of neutrality on his part for which he may be made responsible by such belligerent as has suffered through the violation of neutrality committed by the other belligerent and acquiesced in by the neutral. For instance, if belligerent men-of-war seize enemy vessels in ports of a neutral, and if the neutral, who could not or did not prevent this, exacts no reparation from the belligerent concerned, the other party may make the neutral responsible for the losses sustained.
[712] See articles 25 and 26 of Convention XIII. This duty is nowadays universally recognised, but before the nineteenth century it did not exist, although the rule that belligerents must not commit hostilities on neutral territory, and in especial in neutral ports and waters, was well recognised. That in spite of its recognition this rule was in the eighteenth century frequently infringed by commanders of belligerent fleets, may be illustrated by many cases. Thus, for instance, in 1793, the French frigate Modeste was captured in the harbour of Genoa by two British men-of-war (see Hall, § 220). And in 1801, during war against Sweden, a British frigate captured the Freden and three other Swedish vessels in the Norwegian harbour of Oster-Risoer (see Ortolan, II. pp. 413-418).
Case of the General Armstrong.