Behind the events just described was a con troversy within German governmental circles. Admiral von Tirpitz, head of the naval adminis tration, belongd' to the German school which held that all means of distressing the enemy are justifiable. He favored relentless submarine warfare from the beginning. Chancellor von Bethmann-Hollweg took the diplomatist's point of view. It was Ins to malce diplomacy success ful, and he was in conflict with the military authorities in regard to submarine warfare. On 16 March 1916, von Tirpitz resigned and was succeeded by Admiral von Candle. Then came an outburst of popular indignation; for the sub marine policy was approved by the masses of Germans, who wished to strike Britain in any way possible. The political part of the govern ment had the support of the kaiser for the time being and had its way in the end.
By the end of the year, however, it was evident that Germany was not winning the war and the military party became more than ever insistent on the unrestricted use of submarines. So great was the protest that the statesmen could not withstand it, and on 31 Jan. 1917, the German. goveniment announced the immediate resumption of unrestricted warfare. The com munication awakened a storm of protest in the United States and left that nation no choke between war and inglorious submission. Ger many was prepared for the declaration of war that came on 6 April. She did not believe the United States would be a serious factor in the fighting and she believed that the gain from the destruction of Britain's commerce would more than offset the military damage America could inflict on Germany. Happily in each respect she was to find herself mistaken.
The year following 1 Feb. 1917, was the year of supreme test for the submarine. During the period of restricted use the Germans had been actively engaged in improving this type of craft, making it larger and capable of wider cruising radius and heavier armaments. When the war began it was believed that a submarine's cruising range was little more than 300 mile_s. In February 1915, German submarines were working in the Irish Sea, 1,000 miles from Kiel, and three months later they were in the Mediterranean, 2,500 miles from their bases. In the latter achievement it was believed that they were aided in their progress by supply ships dis guised as neutral traders. In July 1916, the world had a still more. striking demonstration' of the development of the submarine, when the Deutschland, a submarine of commerce, reached' Baltimore, Md, a distance of more than 4,000, miles from Hamburg. On 7 Oct 1916, the Ger- man U-53 arrived at Newport, k. 1., remained in port a few hours, and sailed for home without taking in supplies, loitering two days near Nan tucket where she sunk eight vessels, two of them neutrals. NAThen unrestricted warfare began in February 1917, the best German U-boats had an operating radius of 10,000 miles, a surface speed of 25 miles an hour, and carried six-inch guns with a range of 6,000 yards. It is probable that the possession of these improved vessels served to whet the desire for unrestricted use of them. So confident were the defenders of the policy that they promised the people that three months of it would see the British on their knees suing for peace. How near they came to making good
their threat the allied public did not know until the war ended. Admiral Sims is authority for the statement that in April 1917, when he arrived in England to represent the United States in naval matters, the sinlcing reached nearly 900,000 tons a month, which was three or four times the amount announced officially. At that time and until the end of the war the earnest efforts of Britain, the United States and France were concentrated in combatting the activities of sub marines.
The means employed for this purpose were such as experience dictated. By carefully stretching nets across the British Channel that means of exit had been closed. Steps were now taken to establish a mine barrage from Scotland to the coast of Norway, consisting of a line of .several mines one above another. It was a gigantic undertaking but was accom plished. largely through the efforts of American , naval engineers. To combat the submarine itself depth bombs were used. When these powerful explosives went off near a submerged U-boat the concussion was likely to damage the delicate mechanism of the boat or crush its thin sides. From June 1917 to November 1918, more than 2,000,000 United States troops were carried across the Atlantic to the battlefields of France, despite the submarines. Careful convoying kept them safe. In general the same thing was true oi the vast supply service that supported these troops in France, and of the regular. trade with, Great Britain and France. In the beginning of, the war the British did not use .the convoy method, partly because of the demaud it made on the navy for destroyers, which: were needed in other capacities, partly because. it was a slow system of moving ships, and partly, per haps, of an inherent British unwillingness to admit that they were forced to extreme• meta" ures by their enemies. When the AmericannavY became available .the convoy system became more feasible than when it depended on. the navy of the Allied powers..already ployed in guarding the Nits in which the-Ger4 man and Austrian fleets were shut .up. The construction, of destroyers also promoted the US0 of convoys. • The most considerable event in counection with the warfare against die submarines wia,4thi attacic on the submarine bases at Zeebrugge' and Ostend, on the Etelgian Coast. These:two partie not only harbored the submarines that Went out to,the'southern 'coastil of England but a large number of destroyers and light cruisers that were accustomed to raid the fishing fleet and otherwise disturb Allied shipping in the North Sea. If these bases could be closed the de stroyers set to NS atch them could be used against submarines on the ocean lanes and the mine fields in the North Sea could be extended so that the region would be firee from the craft of the enemy. The ports were well fortified and defended by mine fields, but a plan was made to enter them and block their channels and its execution was entrusted to Rear-Admiral Keyes, who had seen good service at the Dar danelles. It involved the sinking at night of ships laden with concrete in the narrow channels. It was believed that once they were sunk the shifting sands of the coast would accumulate around them and make obstructions not easily, removed.