[136] Concerning the question whether an enemy merchantman, captured on the High Seas, may at once be converted into a warship, see below, [p. 231, note 2].
The Crews of Merchantmen.
§ 85. In a sense the crews of merchantmen owned by subjects of the belligerents belong to the latter's armed forces. For those vessels are liable to be seized by enemy men-of-war, and if attacked for that purpose they may defend themselves, may return the attack, and eventually seize the attacking men-of-war. The crews of merchantmen become in such cases combatants, and enjoy all the privileges of the members of armed forces. But unless attacked they must not commit hostilities, and if they do so they are liable to be treated as criminals just as are private individuals who commit hostilities in land warfare. Some writers[137] assert that, although merchantmen of the belligerents are not competent to exercise the right of visit, search, and capture towards neutral vessels, they may attack enemy vessels—merchantmen as well as public vessels—not merely in self-defence but even without having been previously attacked, and that, consequently, the crews must in such case enjoy the privileges due to members of the armed forces. But this opinion is absolutely without foundation nowadays,[138] even in former times it was not generally recognised.[139]
[137] See Wheaton, § 357; Taylor, § 496; Walker, p. 135, and Science, p. 268.
[138] See below, § [181], and Hall, § 183.
[139] See Vattel, III. § 226, and G. F. Martens, II. § 289.
It should be mentioned in regard to the fate of the crews of captured merchantmen that a distinction is to be made according as to whether or no a vessel has defended herself against a legitimate attack. In the first case the members of the crew become prisoners of war, for by legitimately taking part in the fighting they have become members of the armed forces of the enemy.[140] In the second case, articles 5 to 7 of Convention XI. of the Second Peace Conference enact the following rules:[141]—
(1) Such members of the crew as are subjects of neutral States may not be made prisoners of war.
(2) The captain and the officers who are subjects of neutral States may only be made prisoners if they refuse to give a promise in writing not to serve on an enemy ship while the war lasts.
(3) The captain, officers, and such members of the crew who are enemy subjects may only be made prisoners if they refuse to give a written promise not to engage, while hostilities last, in any service connected with the operations of war.