Those who have failed to adjust their tactical thinking to the realities of 1940 take it for granted that the old pattern of battle will be followed. Wherefore they assume that the stage is now merely being set for the regulation war of mile-by-mile conquest. But soon it should become apparent that something new and unique is transpiring. The classic all-air battel foreseen by a few of the more imaginative tacticians, aware of the potentialities of the new weapon, has become a fact. When the question of mastery of the skies over the British Isles and their sea approaches is definitely answered by the course of the present 'aerial Trafalgar', the other questions sill remaining to be answered with the aid of armies and navies will be minor by contrast, from the strategic point of view. … the air engagement … may not be decided for weeks and even months.