The reports by Mr. Roger Allen culminate in the assertion that the German U-boats, beginning with the summer of 1940, torpedoed everything within range. Undoubtedly, the methods of submarine warfare gradually intensified under the pressure of the measures directed against Germany. This war, however, never degenerated into an orgy of shooting governed only by the law of expediency. Most of what might have been expedient for a U-boat was left undone to the last day of the war because it could only be regarded as legally inadmissible, and all measures of which Germany in her conduct of naval warfare is being accused today by the Prosecution were the result of a development in which both sides took part through measures and countermeasures, as occurs in the course of every war.
The London Protocol of 1936 formed the legal basis for German submarine warfare at the beginning of this war. These regulations were incorporated verbatim into Article 74 of the German Prize Ordinance, which even Mr. Roger Allen calls a reasonable and not inhuman instrument. This Prize Ordinance was sent in 1938 in draft form to the two U-boat flotillas and to the U-boat training school and served as a basis for the training of commanders. Stopping and examining merchant vessels was performed as a tactical task. In order to facilitate for the commander in economic warfare the quick and correct evaluation of his legal position towards ships and cargoes of the enemy and of neutral countries, the prize disc was constructed, which through simple manipulations indicated the articles of the Prize Ordinance to be applied. Thus, insofar as preparations had been made at all for economic warfare by submarines they were based exclusively on the German Prize Ordinance, and thus on the London Protocol.
The German High Command actually did adhere to this legal foundation in the initial stages of the war. The combat instructions for U-boats of 3 September 1939 contained clear orders to the effect that submarine warfare was to be carried on in accordance with the Prize Ordinance. Accordingly, sinkings were permissible only after stopping and examining the ship, unless it attempted to escape or offered resistance. Some examples were submitted to the Tribunal, from the abundance of available instances, showing the chivalrous spirit in which the German submarine commanders complied with instructions given. In particular, assistance afforded to the crews of ships lawfully sunk, after having been stopped and examined, occasionally reached a point where it could scarcely be justified on military grounds. Lifeboats were towed over long distances, whereby the few available U-boats were diverted from their combat mission. Enemy ships which might have been sunk lawfully were permitted to go free in order to send the crews of ships previously sunk to port aboard them. It is therefore only correct that Mr. Roger Allen stated that the German U-boats, during the first weeks of the war, adhered strictly to the London regulations.
Why was this practice not kept up? Because the conduct of the enemy made such a procedure militarily impossible, and at the same time created the legal prerequisites for its modification.
I shall consider the military side first. From the very first day of the war, U-boat reports reached the Flag Officer of U-boats and the Naval Operations Staff stating that hardly an enemy ship submitted voluntarily to being stopped and examined. The merchant vessels were not content with attempting to escape through flight or by changing their course and bearing directly down upon the U-boat in order to force it to dive. Every U-boat sighted was at once reported by radio; and subsequently, in the shortest space of time, attacked by enemy airplanes or naval forces. However, it was the arming of all enemy merchant vessels that settled the matter. As early as 6 September 1939 a German U-boat was shelled by the British steamship Manaar, and that was the starting signal for the great struggle which took place between the U-boats, on the one hand, and the armed merchant vessels equipped with guns and depth charges, on the other hand, as equal military opponents.
In order to show the effect of all the measures taken by the adversary, I have presented to the Tribunal some examples which I do not wish to repeat. They show unequivocally that further action against enemy merchant ships in accordance with the Prize Ordinance was no longer feasible from the military standpoint and meant suicide for the submarine. Nevertheless, the German command for weeks on end continued to act according to the regulations governing the Prize Ordinance. Only after it was established that action on the part of enemy merchant ships—especially armed action—no longer took the form of individual measures but of general instructions, was the order given on 4 October 1939 to attack all armed enemy merchant ships without warning.
The Prosecution will perhaps take the standpoint that, in lieu of this, submarine warfare against armed merchant vessels should have been discontinued. In the last war the most terrible weapons of warfare were ruthlessly employed by both sides on land and in the air. In view of this experience the thesis can hardly be upheld today that in naval warfare one of the parties waging war should be expected to give up using an effective weapon after the adversary has taken measures making the use of it impossible in its previous form. In any case such a renunciation could only be considered if the novel utilization of the weapon were undeniably illegal. But this is not the case for the utilization of German submarines against enemy merchant shipping, because the measures taken by the enemy changed not only the military but also the legal situation.
According to German legal opinion a ship which is equipped and utilized for battle does not come under the provisions granting protection against sinking without warning as laid down by the London Protocol for merchant ships. I wish to stress the fact that the right of the merchant ship to carry weapons and to fight is not thereby contested. The conclusion drawn from this fact is reflected in the well-known formula: “He who resorts to weapons must expect to be answered by weapons.”
During cross-examination the Prosecution referred to this interpretation of the London Protocol as fraudulent. It admits only the closest literal interpretation and considers the sinking of a merchant ship as admissible only if the latter has offered active resistance. It is not the first time that fundamental differences of opinion exist between contracting parties with respect to the interpretation of a treaty, and the extremely divergent interpretations of the meaning of the Potsdam Agreement of 2 August 1945 provide a recent example. Diversity of conception, therefore, does not permit the conclusion that the one or the other party acted fraudulently during the signing or the subsequent interpretation of a treaty. I will endeavor to show how unjustified this charge is particularly in regard to the German interpretation of the London Submarine Protocol.
There are two terms on which the German interpretation hinges, namely, that of “merchant vessel” and “active resistance.” If I now consider some legal questions, this will in no way represent a comprehensive exposition. I can only touch on the problems and due to lack of time must limit myself also when dealing with research on the subject. I shall primarily refer to American sources, because the interests of naval strategy of that nation were not as firmly established as those of the European nations and its research literature can thus claim greater objectivity.