escorts for the transports. But this was not the only responsibility of the kind that rested on the overburdened British shoulders. There was another part of the seas in which, for practical and political reasons, the British destroyer fleet had to do protective duty. In the Mediterranean lay not only the trade routes to the East, but also the lines of supply which extended to Italy, to Egypt, to Palestine, and to Mesopotamia. If Germany could have cut off Italy's food and materials Italy would have been forced to withdraw from the war. The German and Austrian submarines, escaping from Austria's Adriatic ports, were constantly assailing this commerce, attempting to do this very thing. Moreover, the success of the German submarine campaign in these waters would have compelled the Allies to abandon the Salonika expedition, which would have left the Central Powers absolute masters of the Balkans and the Middle East. For these reasons it was necessary to maintain a considerable force of destroyers in the Mediterranean.
For the British navy it was therefore a matter of choice what areas she would attempt to protect with her destroyer forces; the one thing that was painfully apparent was that she could not satisfactorily safeguard all the danger zones. With the inadequate force at her disposal it was inevitable that certain areas should be left relatively open to the U-boats; and the decision as to which ones these should be was simply a matter of balancing the several conflicting interests. In April, 1917, the Admiralty had decided to give the preference to the Grand Fleet, the hospital ships, the Channel crossing, and the Mediterranean, practically in the order mentioned. It is evident from these facts that nearly the entire destroyer fleet must have been disposed in these areas. This decision, all things considered, was the only one that was possible ; yet, after placing the destroyers in these selected areas, the great zone of trans-Atlantic shipping, west and south of Ireland, vitally important as it was, was necessarily left inadequately protected. So desperate was the situation that sometimes only four or five British destroyers were operating in this great stretch of waters; and I do not think that the number ever exceeded fifteen. Inasmuch as that represented about the number of German submarines in this same area, the situation may strike
