§ 39. Reprisals, be they positive or negative, must be in proportion to the wrong done and to the amount of compulsion necessary to get reparation. For instance, a State would not be justified in arresting by way of reprisal thousands of foreign subjects living on its territory whose home State had injured it through a denial of justice to one of its subjects living abroad. But it would in such case be justified in ordering its own Courts to deny justice to all subjects of such foreign State, or in ordering its fleet to seize several vessels sailing under the latter State's flag, or in suspending its commercial treaty with such State.
Embargo.
§ 40. A kind of reprisal, which is called Embargo, must be specially mentioned. This term of Spanish origin means detention, but in International Law it has the technical meaning of detention of ships in port. Now, as by way of reprisal all acts, otherwise illegal, may be performed, there is no doubt that ships of the delinquent State may be prevented from leaving the ports of the injured State for the purpose of compelling the delinquent State to make reparation for the wrong done.[39]
[39] Thus in 1840—see above, § [34]—Great Britain laid an embargo on Sicilian ships.
The matter would not need special mention were it not for the fact that embargo by way of reprisal is to be distinguished from detention of ships for other reasons. According to a now obsolete[40] rule of International Law, conflicting States could, when war was breaking out or impending, lay an embargo on, and appropriate each other's merchantmen. Another kind of embargo is the so-called arrêt de prince[41]—that is, a detention of foreign ships for the purpose of preventing them from spreading news of political importance. And there is, thirdly, an embargo arising out of the so-called jus angariæ—that is, the right of a belligerent State to seize and make use of neutral property in case of necessity, under the obligation to compensate the neutral owner of such property. States have in the past[42] made use of this kind of embargo when they had not enough ships for the necessary transport of troops, ammunition, and the like.
[40] See, however, below, § [102a] and article 1 of Convention VI., which only stipulates that it is desirable that enemy vessels in the port of a belligerent at the outbreak of war should be allowed to depart freely; see also article 2 of Convention VI.
[41] See Steck, Versuch über Handels-und Schiffahrts-Verträge (1782), p. 355; Caumont, Dictionnaire universel de droit maritime (1867), pp. 247-265; Calvo, III. § 1277; Pradier-Fodéré, V. p. 719; Holtzendorff, IV. pp. 98-104.
These kinds of international embargo must not be confounded with the so-called civil embargo of English Municipal Law[43]—namely, the order of the Sovereign to English ships not to leave English ports.
[43] See Phillimore, III. § 26.