File No. 763.72111M72/9

The Chargé in the Netherlands ( Langhorne ) to the Secretary of State

No. 879

Sir: I have the honor to transmit herewith a copy and translation of a communication dated April 14, 1917, from the Royal Spanish Minister at The Hague, enclosing certain correspondence regarding the American citizens captured by the German cruiser Moewe, which the Spanish Ambassador at Berlin forwarded to The Hague for the information of this Legation.1

I have [etc.]

Marshall Langhorne

Memorandum of the German Government Relative to the Treatment of Neutral Members of Crews of Enemy Merchantmen

Various neutral governments have made representations to the Imperial German Government because German naval forces have made prisoners of war of seamen of their respective nationality belonging to the crews of armed enemy merchantmen. In so doing the neutral governments have relied partly on existing treaties and partly on general principles of international law to which this procedure is contended to be repugnant.


Germany has not concluded with any power special treaties regarding the treatment of neutral nationals who perform service on board of merchantmen of enemy powers during a war carried on by Germany. The German Government is not aware of any such treaties between other countries.

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The sole treaty which might be considered in this connection is a collective treaty, the ninth Hague convention of October 18, 1907, regarding certain restrictions of the right of capture in maritime war. Article 5 of this convention provides that neutral seamen serving on board of enemy merchant ships can not be made prisoners of war and that officers can not be made prisoners unless they refuse to promise not to serve any more on an enemy ship.

This treaty stipulation is, however, not binding on any of the belligerent powers in the present naval war. For pursuant to Article 9, the convention does not apply unless all the belligerents are contracting parties; now a considerable number of the belligerents, among them Russia and Italy in particular, have not ratified the convention. Thus the convention has no validity in the present war, so that no neutral power can rely on the provisions of Article 5.


The action of the German naval forces is likewise unimpeachable according to general principles of international law, for these principles undoubtedly permit neutral seamen serving on enemy merchantmen to be made prisoners of war. In the proceedings relative to the ninth Hague convention this was universally conceded.

Article 5 of that convention originated in a motion of the British delegation, in the course of the discussion of which it was established, especially by the British and the Italian delegations, that the intention of the proposal was to create a privilege theretofore unknown which constituted a marked advance over the existing legal status. (Consult Akten und Dokumente der zweiten Intemationalen Friedenshonferenz, Band III, pp. 978, 1074.1) In agreement with this the report of the committee set forth in detail that according to present day practice of international law the crew, the officers, and the captain of a captured enemy merchantman would be treated as prisoners of war regardless of whether the crew were of neutral or enemy nationality. In its recommendations the report points out that this fully established practice had undergone various [modifications] and terms the resolutions of the examining committee the expression of the universal wish to bring about a moderation, that is to say a change, of the existing practice. (See ibid., pp. 1027–1028.2)

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It follows that Germany is undoubtedly justified in applying the existing stricter rules in the treatment of neutral crews of enemy merchantmen in the present naval war.


Heretofore the German Government has merely made prisoners of war of such neutral seamen only as had permitted themselves to be hired for service on armed enemy merchantmen. It has already expressed its intention of making these seamen prisoners of war in its memorandum of February 8, 1916, relative to the treatment of armed merchantmen,1 in which it declared that it would consider such vessels as belligerents. There was moreover agreement at the Second Hague Peace Conference, that the privilege introduced by Article 5 of the convention mentioned could not be extended to the neutral crews of such enemy vessels as took any part in hostilities.

If the German Government has occasionally made exceptions to the rule of treating neutral members of the crews of enemy merchantmen as prisoners of war, this was done for humanitarian reasons and after taking into consideration the circumstance that the men concerned had no knowledge of the armament of the ship or of its consequences in international law when they were hired. The German Government is, however, no longer in a position to permit any such exceptions, since its attitude regarding this question and the general armament of enemy merchantmen has in the meantime become generally known.


The German Government must further keep a free hand for decision as to whether it will not in future treat also the neutral members of the crews of unarmed merchantmen as prisoners of war. It would not only be quite justified in so doing according to the principles of existing international law, as shown above, but such action would also be responsive to the action of the enemies of Germany, since they are conducting naval warfare recklessly and pitilessly in every respect; in addition, the enemy governments have claimed the entire merchant marines of their countries for war purposes, so that every neutral accepting service in an enemy marine aids the war purposes of the enemy.


In view of this situation the German Government expressly directs the attention of the neutral governments to the fact that every one of their nationals performing service on board of an enemy merchantman [Page 218] exposes himself to the danger of becoming a prisoner of war if the ship is captured. It therefore suggests that the neutral governments warn their subjects not to enter the merchant marine of powers at war with Germany.

  1. The German memorandum of Mar. 30, 1917, only, is printed.
  2. Deuxième Confèrence Internationale de la Paix, Actes et Documents (La Haye, 1907), vol. iii. pp. 978, 1074; English translation of the Carnegie Endowment for International Peace (New York, Oxford University Press, 1921), pp. 965, 1061.
  3. Actes et Documents, pp. 1027–1028; Carnegie Endowment translation, pp. 1012–1013.
  4. Foreign Relations, 1916, Supplement, p. 163.