These statements now read almost like ancient history, yet they were made in February, 1917. At that time, Americans and Englishmen read them with a smile; they seemed to be the kind of German rodomontade with which the war had made us so familiar; they seemed to be empty mouthings put out to bolster up the drooping German spirit. That the Kaiser and his advisers could really believe such rubbish was generally regarded as absurd. Yet not only did they believe what they were saying but, as already explained, they also had every reason for believing it. The Kaiser and his associates had figured that the war would end about July 1st or August 1st; and English officials with whom I came in contact placed the date at November 1st--always provided, of course, that no method were found for checking the submarine.[2] II How, then, could we defeat the submarine? Before approaching this subject, it is well to understand precisely what was taking place in the spring and summer of 1917 in those waters surrounding the British Isles. What was this strange new type of warfare that was bringing the Allied cause to its knees? Nothing like it had ever been known in recorded time; nothing like it had been foreseen when, on August 4, 1914, the British Government threw all its resources and all its people against the great enemy of mankind. Leaving entirely out of consideration international law and humanity, it must be admitted that strategically the German submarine campaign was well conceived. Its purpose was to marshal on the German side that force which has always proved to be the determining one in great international conflicts--sea power. The advantages which the control of the sea gives the nation which possesses it are apparent. In the first place, it makes secure such a nation's communications with the outside world and its own allies, and, at the same time, it cuts the communications of its enemy. It enables the nation dominant at sea to levy upon the resources of the entire world; to obtain food for its civilian population, raw materials for its manufactures, munitions for its armies; and, at the same time, to maintain that commerce upon which its very economic life may depend. It enables such a power also to transport troops into any field of action where they may be required. At the very time that sea power is heaping all these blessings upon the dominant nation, it enables such a nation to deny these same advantages to its enemy. For the second great resource of sea power is the blockade. If the enemy is agriculturally and industrially dependent upon the outside world, sea power can transform it into a beleaguered fortress and sooner or later compel its unconditional surrender. Its operations are not spectacular, but they work with the inevitable remorselessness of death itself.