THROUGH THE fall and winter of 1914, Germany’s submarines came to occupy more and more of Wilson’s attention, owing to a new shift in German naval strategy that brought with it the steadily worsening threat of entanglement. The Aboukir incident, and other successful attacks against British ships, caused German strategists to view submarines in a new light. The boats had proved to be hardier and deadlier than expected, well suited to Germany’s guerrilla effort to abrade the strength of Britain’s Grand Fleet. But their performance also suggested another use. By year’s end, Germany had made the interception of merchant shipping an increasingly important role for the navy, to stanch the flow of munitions and supplies to Allied forces. This task originally had fallen to the navy’s big auxiliary cruisers—former ocean liners converted to warships—but these cruisers had been largely swept from the seas by Britain’s powerful navy. Submarines by their nature offered an effective means of continuing the campaign.
They also raised the risk that an American ship might be sunk by accident, or that U.S. citizens traveling on Allied vessels might be harmed. Early in 1915, this risk seemed to increase sharply. On February 4, Germany issued a proclamation designating the waters around the British Isles an “area of war” in which all enemy ships would be subject to attack without warning. This posed a particularly acute threat to Britain, which, as an island nation that imported two-thirds of its food, was utterly dependent on seaborne trade. Neutral ships were at risk also, Germany cautioned, because Britain’s willingness to fly false flags had made it impossible for U-boat commanders to rely on a ship’s markings to determine whether it truly was neutral. Germany justified the new campaign as a response to a blockade begun previously by Britain, in which the British navy sought to intercept all cargoes headed to Germany. (Britain had more than twice as many submarines as Germany but used them mainly for coastal defense, not to stop merchant ships.) German officials complained that Britain made no attempt to distinguish whether the cargoes were meant for hostile or peaceful use and charged that Britain’s true goal was to starve civilians and thereby “doom the entire population of Germany to destruction.”
What Germany never acknowledged was that Britain merely confiscated cargoes, whereas U-boats sank ships and killed men. German commanders seemed blind to the distinction. Germany’s Admiral Scheer wrote, “Does it really make any difference, purely from the humane point of view, whether those thousands of men who drown wear naval uniforms or belong to a merchant ship bringing food and munitions to the enemy, thus prolonging the war and augmenting the number of women and children who suffer during the war?”
Germany’s proclamation outraged President Wilson; on February 10, 1915, he cabled his formal response, in which he expressed incredulity that Germany would even think to use submarines against neutral merchant ships and warned that he would hold Germany “to a strict accountability” for any incident in which an American ship was sunk or Americans were injured or killed. He stated, further, that America would “take any steps it might be necessary to take to safeguard American lives and property and to secure to American citizens the full enjoyment of their acknowledged rights on the high seas.”
The force of his prose took German leaders by surprise. Outwardly, Germany seemed a fierce monolith, united in carrying out its war against merchant ships. But in fact, the new submarine campaign had caused a rift at the highest levels of Germany’s military and civilian leadership. Its most ardent supporters were senior naval officials; its opponents included the commander of Germany’s military forces in Europe, Gen. Erich von Falkenhayn, and the nation’s top political leader, Chancellor Theobald von Bethmann Hollweg. Moral scruple had nothing to do with their opposition. Both men feared that Germany’s undersea war could only lead to disaster by driving America to shed its neutrality and side with Britain.
Wilson’s protest, however, did not impress Germany’s submarine zealots. They argued that if anything Germany should intensify its campaign and destroy all shipping in the war zone. They promised to bring Britain to heel well before America could mobilize an army and transport it to the battlefield.