order to pick up the trail or get on the track of a submarine that has been temporarily lost. It is thus only when the number of machines and the organisation is sufficiently developed that the power of aircraft as controlling submarine activity will be fully realised.
§ 119. The Strategic Employment of Aircraft on a Large Scale. It is becoming more and more clear as time goes by that the future of Aircraft in Warfare is a subject of such vast potentiality that we may to-day consider ourselves only on the outer fringe of developments destined ultimately to carry us far beyond anything yet conceived. We are at present only on the threshold of a revolution which aircraft will ultimately bring about in the conduct of warfare.
Thus, in the existing phase of the present war, were our aircraft of sufficient numerical strength, it would no longer be a matter of individual and isolated raids on selected places at which the maximum of injury could be inflicted, but rather a continuous and unrelenting attack on each and every point of strategic importance. Depôts of every kind in the rear of the enemy's lines would cease to exist; rolling stock and mechanical transport would be destroyed; no bridge would be allowed to stand for 24 hours; railway junctions would be subject to continuous bombardment, and the lines of railway and roads themselves broken up daily by giant bombs to such an extent as to baffle all attempts to maintain or restore communication.
In this manner a virtually impassable zone would be created in the rear of the enemy's defences, a zone varying, perhaps, from 100 to 200 miles in width. Once this condition has been brought about, the position of the defending force must be considered as precarious; not only will the defence be slowly strangled from the uncertainty and lack of supplies of all kinds, but ultimately retreat will become impossible. The defending
187
