For this patrol the navy was impressing into service all the destroyers, yachts, trawlers, sea-going tugs, and other light vessels which could possibly be assembled; almost any craft which could carry a wireless, a gun, and depth charges was boldly sent to sea. At this time the vessel chiefly used was the destroyer. The naval war had demonstrated that the submarine could not successfully battle with the destroyer; that any U-boat which came to the surface within fighting range of this alert and speedy little surface ship ran great risk of being sunk. This is the fundamental fact that the destruction of the submarine was highly probable, in case the destroyer could get a fair chance at her—which regulated the whole anti-submarine campaign. It is evident, therefore, that a proper German strategy would consist in so disposing its submarines that they could conduct their operations with the minimum risk of meeting their most effective enemies, while a properly conceived Allied strategy would consist in so controlling the situation that the submarines would have constantly to meet them. Frankness compels me to say that, in the early part of 1917, the Germans were maintaining the upper hand in this strategic game; they were holding the dominating position in the campaign, since they were constantly attacking Allied shipping without having to meet the Allied destroyers, while the Allied destroyers were dispersing their energies over the wide waste of waters. But the facts in the situation, and not any superior skill on the part of the German navy, were giving the submarines this advantage. The British were most heroically struggling against the difficulties imposed by the mighty task which they had assumed. The British navy, like all other navies, was only partially prepared for this type of warfare; in 1917 it did not possess destroyers enough both to guard the main fighting fleet and to protect its commerce from submarines. Up to 1914, indeed, it was expected that the destroyers would have only one function to perform in warfare, that of protecting the great surface vessels from attack, but now the new kind of warfare which Germany was waging on merchant ships had laid upon the destroyer an entirely new responsibility; and the plain fact is that the destroyers, in the number which were required, did not exist.
The problem which proved so embarrassing can be
