A future war, as I see it, will begin something after this manner, provided either side possesses large air forces. Huge day and night bombers will assemble at the declaration of war to penetrate into the enemy's country for the attack of his centres of population, his mobilization zones, his arsenals, harbours, strategic railways, shipping and rolling stock. Corps and Army squadrons will concentrate in formation to accompany the armies to the front; reconnaissance and fighting patrols will scatter in all directions from coastal air bases to discover the enemy's concentrations and cover our own; the fleet, whatever its nature, will emerge with its complement of reconnaissance and protective machines and torpedo aircraft for direct action against the enemy's fleet. A few fighting defence units will remain behind. But it must not be imagined that these functions will be carried out unopposed. Local battles in the air will occur between fighting machines for the protection of specialized machines, while the main air forces in large formations will concentrate independently to produce, if possible, a shattering blow on the enemy and obtain from the outset a supremacy in the air comparable to our supremacy on the sea in the last war. In mobilization the time factor is all-important. Our national history has been one of extraordinary good fortune in this respect, but the margin allowable for luck is becoming very narrow and, whereas in 1914 it was some twenty days between the declaration of war and the exchange of the first shots, in the next war the air battle may be joined within as many hours, and an air attack launched almost simultaneously with the declaration of war. In modern war the mobilization period tends to shorten, and every effort will be made towards its further reduction, since mobilizing armies are particularly vulnerable from air attack. CIVIL AVIATION AS A FACTOR IN NATIONAL SECURITY. The picture I have drawn may appear highly coloured for the reason that no country is likely for some time to possess sufficiently large air forces to obtain a decisive victory, or at any rate an uncontested superiority, at the outbreak of war. Though in air, as in every other form of warfare, attack is more effective than defence, we cannot afford to keep our air forces up to war strength in peace any more than our Army or Navy.