Secretary Lansing later issued a ruling of the State Department defining the status of armed merchant ships. Germany was thereby notified that the United States recognized the equity of her argument—that if a vessel was armed and used its armament to attack a submarine the latter could not be called upon to give warning in advance, for in so doing the safety of the submarine and its crew was imperiled. But the United States reiterated what it had frequently pointed out before as the only criterion governing such occurrences—each case must be judged by itself. Only a belligerent vessel which had been proved guilty of such an offensive use of armament could be regarded as a warship. The presence of armament could not of itself be construed as a presumption of hostility. Summarized, the State Department's ruling laid down:
(1) That the status of an armed merchantman must in each case be determined before it could be regarded as a warship—a neutral government, on entry of the ship into port, presuming that the armament was aggressive unless the belligerent proved otherwise.
(2) The belligerents on the high seas must assume that the armed ship carried armament only for protection, and, unless resistance or an attempt to escape was immediately made, the merchantman could not be attacked without receiving due warning.
(3) That Americans and all others who took passage on armed ships intermittently engaged in commerce raiding could not expect to be immune, for such vessels acquired a "hostile taint." This was Germany's contention; but the United States refused to agree to the German idea that, because a few British vessels might be guilty of wrongful use of armament, all British ships must consequently be regarded as warships.
(4) The right of "self-protection" could be exercised by an armed merchantman; and this was different from cruising the high seas for the special purpose of attacking hostile ships.
(5) If belligerent vessels were under orders to attack submarines in all circumstances they lost their status as "peaceful merchantmen." Germany claimed England had so ordered. England denied the charge. Evidence in each case must reconcile the difference of opinion.
The Administration's position in the submarine issue with Germany, now that Congress had upheld the President, seemed to be that Germany's decree condemning armed merchantmen curtailed the liberty of Americans to travel on the high seas. The status quo had not been affected. Germany, in the Arabic case, had undertaken that merchant vessels would not be torpedoed without first being warned, and that pledge the United States looked to her to respect, whether the vessels were armed for defense or not. What, then, would now happen, with Germany's latest decree sent ringing round the world with resounding bombast, by way of telling neutral noncombatants, including Americans, to stay at home, as though cataclysmic destruction awaited all vessels which dared to show a gun at the stern? The United States waited. Nothing, so far as the German armed-merchantmen decree was concerned, did happen. There was no appreciable increase in the number of vessels sunk by Teutonic submarines, and armed merchantmen did not especially figure among the victims.
In the face of this tame execution of the terrible decree, providing a sorry anticlimax to its noisy proclamation, the German press called for a policy of no compromise with the United States. The "Berliner Tageblatt" announced that Germany intended to wage a ruthless U-boat war against her enemies, whatever the American attitude might be. Apparently the German people believed that a renewal of submarine activity was vitally necessary, and were convinced of the propriety of their stand, both from the point of view of ethics and international law. Germany's armed-merchantmen decree, as indicated, was not immediately followed by any submarine activity of a character in keeping with the dire threat made; but toward the close of March, 1916, a sudden indiscriminate outbreak of destruction came against merchantmen of every type. Many were sunk without warning, the question of whether they were armed or not seemingly being disregarded in the new crusade. The United States began to take stern cognizance of these reckless operations when four ships having Americans on board, either among the crews or passengers, became targets for the kaiser's torpedoes, without warning. These were the Eagle Point, the Manchester Engineer, the Englishman, and the Sussex. All were sunk except the last-named vessel, and the Americans were saved except one on the Englishman, though not, in several cases, without injury.
The circumstances of the torpedoing of the Sussex provoked a final clash between the United States and Germany. This vessel plied as a Channel ferryboat between Folkestone and Dieppe. On March 24, 1916, at 4.30 p. m., while near the latter port, with 436 persons on board, including seventy-five Americans, she was struck by a torpedo from a submarine. The captain observed a torpedo about 100 meters from the side and immediately maneuvered to avoid it; but the vessel was struck in the forward part, which was destroyed. Rescuing craft towed the disabled boat to Boulogne, where a majority of the passengers were landed. About fifty persons lost their lives, and three Americans were hurt.
The State Department at once instructed the American ambassador at Berlin to inquire whether the torpedo which almost sunk the Sussex came from a German submarine, though the Government entertained little doubt that this was the case. The American suspicions were later confirmed by incontestable evidence; but the Government first sought to give Germany the opportunity of having her day in court before acting.