III EFFECTIVENESS OF BLOCKADE
See the literature quoted above at the commencement of § [368].
Effective in contradistinction to Fictitious Blockade.
§ 379. The necessity for effectiveness in a blockade by means of the presence of a blockading squadron of sufficient strength to prevent egress and ingress of vessels became gradually recognised during the first half of the nineteenth century; it became formally enacted as a principle of the Law of Nations through the Declaration of Paris in 1856, and the Declaration of London enacts it by article 2. Effective blockade is the contrast to so-called fictitious or paper blockade, which was frequently practised during the seventeenth, eighteenth, and at the beginning of the nineteenth century.[757] Fictitious blockade consists in the declaration and notification that a port or a coast is blockaded without, however, posting a sufficient number of men-of-war on the spot to be really able to prevent egress and ingress of every vessel. It was one of the principles of the First and of the Second Armed Neutrality that a blockade should always be effective, but it was not till after the Napoleonic wars that this principle gradually found universal recognition. During the second half of the nineteenth century even those States which had not acceded to the Declaration of Paris did not dissent regarding the necessity for effectiveness of blockade.
[757] See Fauchille, Blocus, pp. 74-109.
Condition of Effectiveness of Blockade.
§ 380. The condition of effectiveness of blockade, as defined by the Declaration of Paris, is its maintenance by such a force as is sufficient really to prevent access to the coast. But no unanimity exists respecting what is required to constitute an effective blockade according to this definition. Apart from differences of opinion regarding points of minor interest, it may be stated that in the main there are two conflicting opinions.
According to one opinion, the definition of an effective blockade pronounced by the First Armed Neutrality of 1780 is valid, and a blockade is effective only when the approach to the coast is barred by a chain of men-of-war anchored on the spot and so near to one another that the line cannot be passed without obvious danger to the passing vessel.[758] This corresponds to the practice hitherto followed by France.
[758] See Hautefeuille, II. p. 194; Gessner, p. 179; Kleen, I. § 129; Boeck, Nos. 676-681; Dupuis, Nos. 173-174; Fauchille, Blocus, pp. 110-142. Phillimore, III. § 293, takes up the same standpoint in so far as a blockade de facto is concerned:—"A blockade de facto should be effected by stationing a number of ships, and forming as it were an arch of circumvallation round the mouth of the prohibited port, where, if the arch fails in any one part, the blockade itself fails altogether."
According to another opinion, a blockade is effective when the approach is watched—to use the words of Dr. Lushington[759]—"by a force sufficient to render the egress and ingress dangerous, or, in other words, save under peculiar circumstances, as fogs, violent winds, and some necessary absences, sufficient to render the capture of vessels attempting to go in or come out most probable." According to this opinion there need be no chain of anchored men-of-war to expose any vessels attempting to break the blockade to a cross fire, but a real danger of capture suffices, whether the danger is caused by cruising or anchored men-of-war. This is the standpoint of theory and practice of Great Britain and the United States, and it seems likewise to be that of Germany and several German writers.[760] The blockade during the American War of the whole coast of the Confederate States to the extent of 2500 nautical miles by four hundred Federal cruisers could, of course, only be maintained by cruising vessels; and the fact that all neutral maritime States recognised it as effective shows that the opinion of dissenting writers has more theoretical than practical importance.