By early 1915 it was clear to Germany that its initial land campaign had failed. It was decided that the war would be won by starving Britain into submission, and the task of cutting Britain off from outside support fell to the U-boat. From Berlin came a statement of Germany's intention to wage submarine war against merchant shipping. The waters around Great Britain and Ireland, including the English Channel, were proclaimed a war region.
"On and after February 18 [1915]," the statement said, "every enemy merchant vessel found in this region will be destroyed, without its always being possible to warn the crews or passengers of the dangers threatening."
Neutral ships were also warned of danger in the submarine war region, because the
"misuse of neutral flags ordered by the British government" and "incidents inevitable in sea warfare" made it likely that "attacks intended for hostile ships may affect neutral ships also."
The order was dated February 4, and was signed "Von Pohl, Chief of Marine Staff." It generated outrage among the Allies, and scarcely less indignation among such neutrals as the United States.
The German submarine U-17 (Lieutenant Feldkirchner commanding) was the first to sink a merchantman. The victim was the SS Glitra, flying the "red duster" of the British merchant marine. Its cargo, sewing machines and Scotch whisky, could hardly have been considered unmistakable contraband of war, but Feldkirchner nevertheless ordered its crew into lifeboats and sank it by the simple expedient of spinning open its sea cocks. (It is wryly humorous, in the light of the wide-open submarine warfare against merchant shipping which was soon to follow, that Feldkirchner shortly afterward began to develop a severe case of cold feet, fearing that he had exceeded his authority in scuttling the Glitra. He had visions of a court-martial on his return to port — a possibility that of course never came to pass.)
Only six days after the Berlin declaration of war on merchant shipping went into effect, the SS Harpalion, a British merchantman, was steaming on its way oblivious of the fact that it was framed in the optics of a U-boat's periscope. The date was February 24, 1915, and the time was late afternoon — teatime on any normal British ship. Second Officer Harper remembered afterward that
"we had just sat down to tea, and the chief engineer was saying grace. He had just uttered the words, 'For what we are about to receive may the Lord make us truly thankful,' when there came an awful crash. I never saw such a smash as it caused."
The Harpalion continued its voyage in a vertical direction, and Mr. Harper's tea went untasted.
In short order other British ships went down as well, among them on March 15 the SS Fingal on which there was a stewardess who doubtless would have been more than willing to forego the distinction of being the first woman victim of a submarine.
It was inevitable that, in the course of war against merchant ships, an American ship would be sunk. It happened on May 1, 1915, and the ship was the SS Gulflight, a tanker loaded to the brim with oil from Port Arthur, Texas, and destined for Rouen, France. It was torpedoed off the Scilly Isles south of Britain, and three aboard were lost, including the captain who died of a heart attack a few hours after being rescued. But the sinking of the Gulflight was all but eclipsed by a sinking a week later, a sinking which was perhaps the most important single submarine action of all time because, as it is generally conceded, it was the most important single factor in bringing the United States into the war against Germany.
Almost unnoticed on the shipping page of the New York Times on the very day that the Gulflight went down was an announcement placed by the German Embassy in Washington. It read:
Travelers intending to embark on the Atlantic voyage are reminded that a state of war exists between Germany and her allies and Great Britain and her allies; that the zone of war includes the waters adjacent to the British Isles; that in accordance with formal notice given by the Imperial German Government, vessels flying the flag of Great Britain, or of any of her allies, are liable to destruction in those waters and that travelers sailing in the war zone on ships of Great Britain or her allies do so at their own risk.— IMPERIAL GERMAN EMBASSY
It happened that on the same day that this announcement appeared, the RMS Lusitania, a giant Cunard liner, made its departure from New York, bound for Liverpool, England, with the ensign of a British royal mail ship flying from her staff.
The Lusitania was internationally renowned, the queen of the seas of her day. On board for her fateful trip were 1,255 passengers, including 218 Americans. The crew numbered 651 — more than one for every two passengers.
Capable of high speeds even by the standards of present-day passenger liners, the British liner sighted the coast of Ireland six days after leaving New York. At 2:00 P.M. on May 7, 1915, she was fifteen miles south of the Old Head of Kinsale, having slowed to fifteen knots in order to reach Liverpool on a favorable tide.
At the same time and in the same waters was the U-20, under the command of Kapitanleutnant Walther von Schwieger. Von Schwieger's U-boat had left Wilhelmshaven on April 30 with orders to patrol the south coast of Ireland and sink British shipping. The patrol had not been a spectacular success — only three ships had been sunk — and Schwieger was returning to his home port when he caught sight of the oncoming liner. At first it appeared that the Lusitania would not pass within torpedo range of the U-20, but fifteen minutes after von Schwieger first saw it, the giant ship changed course and came to a heading that would take it near the U-20. Von Schwieger gave the orders that put his submarine in a position to fire at the liner when it came within range.
At 2:09 P.M., with the Lusitania only eight hundred yards away, von Schwieger gave the order that sent a single torpedo surging from its tube. The German submarine captain kept his eye to the periscope as the torpedo streaked through the water. At this moment on the bridge of the Lusitania Second Officer Hefford called out to Captain W. T. Turner: "Here comes a torpedo!"
"I saw a torpedo speeding toward us," declared Captain Turner at the official inquiry later, "and immediately I tried to change our course, but was unable to maneuver out of the way. There was a terrible impact as the torpedo struck the starboard side of the vessel, and a second torpedo followed almost immediately. This one struck squarely over the boilers. I tried to turn the Lusitania shoreward, hoping to beach her, but her engines were crippled and it was impossible."
Captain Turner was wrong in his belief that his ship was struck by two torpedoes. There was only one. Von Schwieger, viewing the scene of chaos through his periscope, also saw a second explosion and noted it in his log. Was it due to a boiler explosion or the detonation of explosives? he wondered. There was considerable evidence that the Lusitania had been carrying eleven tons of explosives, but the consensus was that a massive boiler explosion caused the second blast.
A result of the two explosions was the locking of the Lusitania's engines in the full-speed position, which, together with the increasingly sharp list to starboard, made it extremely difficult to launch lifeboats. Only ten or twelve, including life rafts, got clear. At 2:36, less than thirty minutes after it was hit, the Lusitania sank. Rescue ships arrived two or three hours later, but the disastrous total of 1,198 lives were lost, including 124 Americans.
America's protests were stiff, and public indignation against U-boat warfare rose to a new height. Relations between the United States and Germany grew progressively worse.
The immediate reaction in Germany to the sinking was one of general elation, but the outrage of the United States at the enormous toll of innocent lives began to overshadow the U-20's success even in Germany. Eventually von Schwieger was officially reprimanded for the sinking (to the great disgust of the German submarine service, where it was felt that he was simply obeying orders).
On February 9, 1916, nine months after the event, the German government agreed to pay full indemnities for the American victims. In response to American pressure it pledged that
"unarmed merchantmen shall not be sunk without warning and unless the safety of the passengers and crew can be assured, provided, of course, that the vessels do not try to escape or resist."
Despite this pledge the United States was far from satisfied about the matter.