But the air has introduced a third dimension into warfare, and with the advent of the aeroplane new and boundless possibilities are introduced. Hitherto war has been a gigantic game of draughts. Now it becomes a game of halma. Aircraft enables us _to jump over_ the army which shields the enemy government, industry, and people, and _so strike direct and immediately at the seat of the opposing will and policy_. A nation’s nerve-system, no longer covered by the flesh of its troops, is now laid bare to attack, and, like the human nerves, the progress of civilization has rendered it far more sensitive than in earlier and more primitive times. THE AIR WEAPON In the Great War aircraft filled but an auxiliary _rôle_ to the established arms, and their action against the moral objective was merely sporadic. The blow planned against Berlin, which might have revealed beyond question the decisive influence of the new arm, was still-born because of Germany’s haste to conclude an armistice. Those who depreciate the value of the air attack point to the comparatively small damage wrought by any particular attack in the Great War, arguing also that the influx of recruits after some of them showed that such “frightfulness” brought its own recoil in a stiffening of the national “upper lip.” The best answer to this short-sighted deduction is to present a few facts. Between the 31st of May, 1915, and the 20th May, 1918, the German air-raids over the London area were carried out with an aggregate force of 13 Zeppelins and 128 aeroplanes, dropping in all less than 300 tons of bombs. The total result was 224 fires, 174 buildings completely destroyed, and 619 seriously damaged, a damage estimated in money at something over £2,000,000. This was achieved for the most part in face of strong air and ground defences, and in a war where the total British air force was never markedly inferior in size to its enemy, indeed generally the reverse. Let us for a moment take a modern comparison, simply to point the moral. France has 990 aeroplanes in the home country, Great Britain 312――and this is a notable increase on the situation two years ago. Even allowing an ample margin of aircraft to hold the British air fleet in check, it would be easily possible for a greater weight of bombs to be dropped on London in one day than in the whole of the Great War, and to repeat the dose at frequent and brief intervals. A damage spread over three years is a flimsy basis on which to estimate the moral and material results of such a blow concentrated on a single day, delivered with an accuracy and destructive effect unrealizable by the primitive instruments of 1915–1918. Moreover, what is an air fleet of a thousand compared with future possibilities, as civil aviation develops?