Summary

Portrait of Henry Billings Brown Henry Billings Brown The Adula — Opinion of the Court

A blockade is, however, in some cases, declared by an officer of a belligerent power, and when so declared it will affect the subjects of neutral nations as far as it is authorized, or adopted and ratified, by his government. The implied authority in this respect vested in a naval commander is much greater at a distance from his government than when he is near it. To affect neutral nations, it must be laid by competent authority, and they are affected only in the extent to which it is so laid.' 1 Phillips, Ins.
Source: Wikisource

Portrait of Henry Billings Brown Henry Billings Brown The Adula — Opinion of the Court

The reason for the distinction, given in the authorities, is that a proclaimed blockade is deemed to continue until the blockade is raised by a declaration of the power that established it. But a simple or de facto blockade lasts only so long as the blockading squadron chooses to maintain it by a present and actual force. The reasons for constituting such a blockade may cease at any time, and a neutral vessel, on a peaceful voyage, and not carrying a contraband cargo, may lawfully sail for such a port, and if when she reaches it the blockade continues, is entitled to a warning.
Source: Wikisource

Portrait of Henry Billings Brown Henry Billings Brown The Adula — Opinion of the Court

It is, however, claimed that an actual blockade of Guantanamo had been established by Admiral Sampson early in June, which was in existence at the time the Adula entered that port, and that her master had knowledge of such blockade before leaving Kingston.
To declare a blockade effective against neutrals not carrying contraband goods is said by all the authorities to be one of the highest acts of sovereignty, not to be resorted to except for reasons based on well known principles of modern warfare, and to be proclaimed so as to give full notice to friendly and neutral nations.
Source: Wikisource

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