In view of the transcendent value of aircraft as a means of subduing the enemy will to resist, by striking at the moral objective, the question may well be asked: Is the air the sole medium of future warfare? That this will be the case ultimately we have no doubt, for the advantages of a weapon able to move in three dimensions over those tied to one plane of movement are surely obvious to all but the mentally blind. But we are dealing with the immediate future, and an uncertain period may elapse before aircraft can combine with their superior power of movement the radius of action, reliability and hitting power of the other weapons. In pointing out the decisiveness of an air blow at the enemy nation’s nerve system, we pre-supposed two conditions; first, a superior air force; second, a centralized objective such as a highly-developed industrial state offers. The European nations and Japan afford such a target to air attack, but not so a country as vast as the United States; until the latter develops into a more closely-knit fabric, and the radius of air action is greatly increased, an air attack against it could hardly be decisive, however locally unpleasant. Washington laid in ruins would merely provide “Main Street” with a fresh supply of small talk; New York paralysed would leave the Middle West unmoved, even the desolation of the Pacific coast would but inconvenience the “movie fans” of the nation. Moreover, though, in Europe, an air blow would be decisive, its achievement would probably depend on one side being superior in the air, either in numbers of aircraft or by the possession of some surprise device. Where air equality existed between the rival nations, and each was as industrially and politically vulnerable, it is possible that either would hesitate to employ the air attack for fear of instant retaliation. A boxer with a punch in either fist enjoys both a moral and a physical advantage, and the same is true of a nation that, if its initial air blow is frustrated or is lacking in the necessary margin of superiority, can bring another weapon into play. This truth is but the translation into future grand strategy of the immemorial key to victory used by the Great Captains of War――_striking at the enemy from two directions simultaneously_, so that in trying to parry the one blow he exposes himself to the other. Nevertheless, the continuance of an alternative weapon to the aeroplane does not mean that armies, at least, will survive in their present form. An existing pattern army has as much “punch” as a stuffed bolster――size is no criterion of hitting power. If, however, the sea and land weapons are likely to continue until the air weapon reaches maturity, a study of the future of war would be incomplete without a discussion of their tendencies and development――and of the ways by which they may help to gain the moral objective. THE NAVAL WEAPON