Germany gives way on submarine warfare

On the morning of 1 September 1915 the German ambassador in Washington, Johann Heinrich von Bernstorff, met Secretary of State Robert Lansing, and later that same day he confirmed in writing what he had told him. His instructions concerning the reply to the latest American note on the Lusitania contained, he wrote, the following sentence: “Liners will not be sunk by our submarines without warning and without safety of the lives of non-combatants, provided that the liners do not try to escape or offer resistance.” Bernstorff added that he had no objection to the Americans making any use they wished of this information. Lansing made it public. Thus arose the undertaking that went down in history as the “Arabic pledge”.

The dispute in Berlin

The concession came less than two weeks after U-24 torpedoed the liner Arabic without warning. In his July note President Woodrow Wilson had announced that he would regard further sinkings in which Americans died as “deliberately unfriendly” acts. Berlin understood that this time there was a threat of a break in relations with the United States. On 25 August the Foreign Secretary, Gottlieb von Jagow, told the American ambassador James Gerard that if the Arabic had been sunk as the British press reported, Germany would disavow the act and pay compensation. Gerard reported to Washington that Chancellor Theobald von Bethmann Hollweg had taken this step on his own initiative and that both he and Grand Admiral Alfred von Tirpitz had hurried to the Kaiser.

The decision lay with Wilhelm II. The Chancellor and the Foreign Office wanted submarines to attack passenger ships only according to the rules of prize law, that is, after stopping and warning them. Tirpitz and the Chief of the Admiralty Staff, Gustav Bachmann, opposed any restrictions. On 30 August Gerard telegraphed that according to well-informed people the Chancellor had won. On 2 September he added that Bernstorff had been given wide latitude in his talks with Lansing.

In his letter of 1 September the ambassador added that this policy of his government had been decided before the sinking of the Arabic. This referred to a secret order of June, issued after the Lusitania, which forbade U-boat commanders to attack large passenger ships without warning. The commander of U-24, however, had concluded that the Arabic was trying to ram him, and ignored the ban. Now, for the first time, Germany gave the Americans a written undertaking.

What the pledge was worth

In the United States Bernstorff’s letter was received as a success for the diplomacy of Wilson and Lansing. The undertaking had clear limits, however. It applied only to liners, not to freighters, and it held on condition that the ship did not flee or defend itself. Nor did it settle the matter of the Lusitania or of the Arabic itself. Lansing did not want to discuss the Lusitania until Berlin had dealt with the Arabic case. On 3 September Bernstorff informed him that the submarine that might have sunk the Arabic had not yet returned to base, so there would be no explanation for the time being. The American naval attaché in Berlin predicted that the Germans would try to ride out the crisis with clever wording, without giving lasting guarantees.

The test came quickly. On the evening of 4 September, about 88 nautical miles south-west of the Fastnet Rock off the coast of Ireland, the Allan Line liner Hesperian, bound from Liverpool to Montreal, was torpedoed without warning. According to the ship’s officers she had a gun mounted at the stern, and about forty Canadian soldiers, mostly invalids, were on board. Washington demanded explanations from Berlin.

In the following weeks, however, the German government kept its word more effectively than the sceptics had predicted. At the beginning of September Bachmann was replaced as Chief of the Admiralty Staff by Henning von Holtzendorff, who was regarded as closer to the Chancellor. The Kaiser did not accept Tirpitz’s resignation. On 18 September the new chief of staff in effect ordered submarine operations in the waters around the British Isles to be suspended and confined to the North Sea, where they were to follow the rules of prize law. On 5 October Germany expressed regret for the sinking of the Arabic, disavowed the act of U-24’s commander and agreed to pay compensation. The dispute over the Lusitania went on.