was destined to make our country their enemy. Probably no nation ever adopted a war measure with more confidence in its success. The results which the German submarines
could accomplish seemed at that time to be simply a matter of mathematical calculation. The Germans estimated that they could sink at least 1,000,000 tons a month, com- pletely cut off Great Britain's supplies of food and war materials, and thus end the war by October or November of 1917. Even though the United States should declare war, what could an unprepared nation like our own accomplish in such a brief period? Millions of troops we might indeed raise, but we could not train them in three or four months, and, even though we could perform such a miracle, it was ridiculous to suppose that we could transport them to Europe through the submarine danger zone. I have already shown that the Germans were not alone in thus predicting the course of events. In the month of April, 1917, 1 had found the Allied officials just about as distressed as the Germans were jubilant. Already the latter, in sinking merchant ships, had had successes which almost equalled their own predictions; no adequate means of defence against the submarine had been devised ; and the chiefs of the British navy made no attempts to disguise their apprehension for the future.
Such was the atmosphere of gloom which prevailed in Allied councils in April, 1917 ; yet one year later the naval situation had completely changed. The reasons for that change have been set forth in the preceding pages. In that brief twelve months the relative position of the submarine had undergone a marked transformation. Instead of being usually the pursuer it was now often the pursued. Instead of sailing jauntily upon the high seas, sinking helpless merchantmen almost at will, it was half-heartedly lying in wait along the coasts, seeking its victims in the vessels of dispersed convoys. If it attempted to push out to sea, and attack a convoy, escorting destroyers were likely to deliver one of their dangerous attacks; if it sought the shallower coastal waters, a fleet of yachts, sloops, and subchasers was constantly ready to assail it with dozens of depth charges. An attempt to pass through the Straits of Dover meant almost inevitable destruction by mines; an attempt to escape into the ocean by the northern passage involved the momentary dread of a similar end or the hazard of
