(5) A neutral must prevent belligerent men-of-war admitted into his ports or maritime belt from replenishing with ammunition and armaments, and from adding to their armaments, as otherwise he would indirectly assist them in preparing for hostilities (article 18 of Convention XIII.). And it makes no difference whether the ammunition and armaments are to come from the shore or are to be taken in from transport vessels.
Similarly a neutral must prevent belligerent men-of-war in his ports and roadsteads from carrying out such repairs as would add in any manner whatever to their fighting force. The local authorities of the neutral Power must decide what repairs are absolutely necessary to make these vessels seaworthy, and such repairs are allowed, but they must be carried out with the least possible delay (article 17 of Convention XIII.).
(6) A neutral must prevent belligerent men-of-war admitted into his ports from remaining there longer than is necessary for ordinary and legitimate purposes.[635] It cannot be said that the rule adopted in 1862 by Great Britain, and followed by some other maritime States, not to allow a longer stay than twenty-four hours, is a rule of International Law. It is left to the consideration of neutrals to adopt by their Municipal Law any rule they think fit so long as the admitted men-of-war do not prolong their stay for any other than ordinary and legitimate purposes. Article 12 of Convention XIII. prescribes the twenty-four hours rule only for those neutral countries which have not special provisions to the contrary in their Municipal Laws.[636] But it is agreed—and article 14 of Convention XIII. enacts it—that belligerent men-of-war, except those exclusively for the time devoted to religious, scientific, or philanthropic purposes, must not prolong their stay in neutral ports and waters beyond the time permitted, except on account of damage or stress of weather. A neutral would certainly violate his duty of impartiality if he were to allow belligerent men-of-war to winter in his ports or to stay there for the purpose of waiting for other vessels of the fleet or transports.
The rule that a neutral must prevent belligerent men-of-war from staying too long in his ports or waters, became of considerable importance during the Russo-Japanese War, when the Russian Baltic Fleet was on its way to the Far East. Admiral Rojdestvensky is said to have stayed in the French territorial waters of Madagascar from December 1904 till March 1905, for the purpose of awaiting there a part of the Baltic Fleet that had set out at a later date. The Press likewise reported a prolonged stay by parts of the Baltic Fleet during April 1905 at Kamranh Bay and Hon-kohe Bay in French Indo-China. Provided the reported facts be true, France would seem to have violated her duty of impartiality by not preventing such an abuse of her neutral ports.
(7) A neutral must prevent more than three men-of-war belonging to the same belligerent from being simultaneously in one of his ports or roadsteads unless his Municipal Law provides the contrary (article 15 of Convention XIII.).
(8) At the outbreak of war a neutral must warn all belligerent men-of-war which were in his ports or roadsteads or in his territorial waters before the outbreak of war, to depart within twenty-four hours or within such time as the local law prescribes (article 13[637] of Convention XIII.).
[631] See Curtius, Des navires de guerre dans les eaux neutres (1907).
[633] See article 18 of Convention XIII. and above, § [330].
[634] But Germany has entered a reservation against article 20.