The outstanding cases on which the United States called for an adequate defense from Germany were:
The Rowanmore, British freighter, bound from Baltimore to Liverpool, sunk off Cape Clear on October 25, 1916. Two Americans and five Filipinos were on board. No lives were lost.
The Marina, a British horse carrier, bound from Glasgow to Newport News, sunk without warning off the southwest coast of Ireland on October 29, 1916. She carried a mixed crew of British and Americans. Six Americans lost their lives.
The Arabia, a Peninsular and Oriental passenger liner, sunk in the Mediterranean without warning on November 6, 1916. One American was on board. No lives were lost.
The Columbian, an American steamer, sunk off the Spanish coast on November 8, 1916, after being held up for two days under surveillance by the submarine during a storm.
Germany charged that the Rowanmore attempted to escape on being ordered to stop. Her steering gear was shot away after an hour's chase, when the captain hove to and lifeboats were lowered. The crew complained that the submarine shelled the boats after they had cleared the ship. This the commander denied. The flight of the Rowanmore appeared to deprive her of the consideration due to an unresisting vessel under cruiser warfare.
The Marina carried a defensive gun, as did the Arabia. This fact alone, Germany contended, entitled her submarines to sink both vessels without warning, in addition to the commander's belief in each case that the vessel was a transport in the service of the British admiralty. The American Government was satisfied that neither vessel was engaged in transport service on the voyage in question. In the Arabia's case, 450 passengers were on board, including women and children, who were only saved because the Administration had already held that the gun's presence on a vessel did not deprive her of the right to proper warning before being sunk. Germany admitted liability for sinking the Columbian and agreed to pay for the value of the vessel and the contraband cargo she carried.
The Marina case stood out, in the view of the State Department, as a "clear-cut" violation of Germany's pledges to the United States. Her gun was not used, and no opportunity was afforded for using it. The "presumption" on the part of a German submarine commander that a vessel was a transport was a favorite defense of Germany's and disregarded the American ruling on armed merchantmen, which held that "the determination of warlike character must rest in no case upon presumption, but upon conclusive evidence."
Berlin was looking for trouble. A period of complications in American-German relations was frankly predicted. The Administration was plainly concerned by the situation; but no decision to take action was forthcoming. Its hesitation appeared to be due to the apparent need for a further note to dispose of new interpretations Germany had ingeniously woven in her various excuses by way of evading the letter and spirit of the Sussex agreement. One view of her submarine "rights" which Germany insisted on upholding was that armed merchantmen were not legally immune from attack on sight.
Herr Zimmermann, the German Undersecretary of Foreign Affairs, defined anew his Government's attitude: