PART I

CHAPTER I The New Form of War

THE TECHNICAL MEANS OF WARFARE

AERONAUTICS OPENED up to men a new field of action, the field of the air. In so doing it of necessity created a new battlefield; for wherever two men meet, conflict is inevitable. In actual fact, aeronautics was widely employed in warfare long before any civilian use was made of it. Still in its infancy at the outbreak of the World War, this new science received then a powerful impetus to military development.

The practical use of the air arm was at first only vaguely understood. This new arm had sprung suddenly into the field of war; and its characteristics, radically different from those of any other arm employed up to that time, were still undefined. Very few possibilities of this new instrument of war were recognized when it first appeared. Many people took the extreme position that it was impossible to fight in the air; others admitted only that it might prove a useful auxiliary to already existing means of war.

At first the speed and freedom of action of the airplane — the air arm chiefly used in the beginning — caused it to be considered primarily an instrument of exploration and reconnaissance. Then gradually the idea of using it as a range-finder for the artillery grew up.Next, its obvious advantages over surface means led to its being used to attack the enemy on and behind his own lines, but no great importance was attached to this function because it was thought that the airplane was incapable of transporting any heavy load of offensive materiel.Then, as the need of counteracting enemy aerial operations was felt, antiaircraft guns and the so-called pursuit planes came into being.

Thus, in order to meet the demands of aerial warfare, it became necessary step by step to increase aerial power. But because the needs which had to be met manifested themselves during a war of large scope, the resulting increase was rapid and hectic, not sound and orderly. And so the illogical concept of utilizing the new aerial weapon solely as an auxiliary to the army and navy prevailed for almost the entire period of the World War. It was only toward the end of the war that the idea emerged, in some of the belligerent nations, that it might be not only feasible but wise to entrust the air force with independent offensive missions. None of the belligerents fully worked out this idea, however — perhaps because the war ended before the right means for actuating the idea became available.

Now, however, this idea has emerged again and seems to be impressing itself strongly on the national authorities most concerned with these matters. It is, in fact, the only logical answer to the imperative need of defense against these new weapons of warfare. Essentially man lives close to the earth’s surface, and no doubt he began his battling there. We do not know whether, when he first began to navigate the seas, he regarded naval warfare as a mere auxiliary to land operations; but we do know that from time immemorial we have been fighting on the sea independently of, though in co-operation with, land forces. Today, however, the sky is of far greater interest to man, living on the surface of the earth, than is the sea; and nothing, therefore,can a priori prevent him from reaching the conclusion that the air constitutes a battlefield of equal importance.

Though an army is primarily a land force, it possesses navigable means of warfare which it can use to help integrate its land operations; and that fact does not preclude the navy’s accomplishing, solely with its own naval means, war missions from which the army is completely excluded. Similarly, while a navy is primarily a sea force, it possesses land means of warfare which it may use to assist and integrate its naval operations; and that fact does not preclude the army’s carrying out war missions solely with its own land means, entirely independent of any naval means. In like manner, both the army and navy may well possess aerial means to aid and integrate their respective military and naval operations; but that does not preclude the possibility, the practicability, even the necessity, of having an air force capable of accomplishing war missions solely with its own means, to the complete exclusion of both army and navy.

In such a case, an air force should logically be accorded equal importance with the army and navy and bear the same relation to them as they now bear to each other. Obviously, both the army and the navy, each in its own field, must operate toward the same objective — i. e., to win the war. They must act accordingly, but independently of each other. To make one dependent on the other would restrict the freedom of action of the one or the other, and thus diminish their total effectiveness. Similarly, an air force should at all times co-operate with the army and the navy; but it must be independent of them both.

At this point I should like to outline the general aspects of the problem which faces us today and to emphasize the great importance of it. Now that we are released from the pressure of the World War, with its trial-and-error methods, it behooves us to work toward the solution of this problem by an entirely different method, one calculated to obtain for us the maximum return with the minimum of effort.

The state must make such disposition of its defenses as will put it in the best possible condition to sustain any future war. But in order to be effective, these dispositions for defense must provide means of warfare suited to the character and form future wars may assume. In other words, the character and form assumed by the war of the future is the fundamental basis upon which depends what dispositions of the means of war will provide a really effective defense of the state.

The prevailing forms of social organization have given war a character of national totality —that is, the entire population and all the resources of a nation are sucked into the maw of war.And, since society is now definitely evolving along this line, it is within the power of human foresight to see now that future wars will be total in character and scope. Still confining ourselves to the narrow limits of human foresight, we can nevertheless state, with complete certainty, that probable future wars will be radically different in character from those of the past.

The form of any war — and it is the form which is of primary interest to men of war —depends upon the technical means of war available. It is well known, for instance, that the introduction of firearms was a powerful influence in changing the forms of war in the past. Yet firearms were only a gradual development, an improvement upon ancient engines of war —such as the bow and arrow, the ballista, the catapult, et cetera — utilizing the elasticity of solid materials. In our own lifetime we have seen how great an influence the introduction of small caliber, rapid-fire guns — together with barbed wire — has had on land warfare, and how the submarine changed the nature of sea warfare.

We have also assisted in the introduction of two new weapons, the air arm and poison gas.But they are still in their infancy, and are entirely different from all others in character; and we cannot yet estimate exactly their potential influence on the form of future wars. No doubt that influence will be great, and I have no hesitation in asserting that it will completely upset all forms of war so far known.

These two weapons complement each other. Chemistry, which has already provided us with the most powerful of explosives, will now furnish us with poison gases even more potent, and bacteriology may give us even more formidable ones. To get an idea of the nature of future wars, one need only imagine what power of destruction that nation would possess whose bacteriologists should discover the means of spreading epidemics in the enemy’s country and at the same time immunize its own people. Air power makes it possible not only to make high explosive bombing raids over any sector of the enemy’s territory, but also to ravage his whole country by chemical and bacteriological warfare.

If, then, we pause to take stock of the potentialities of these new weapons — which will no doubt be improved and developed in the future — we must be convinced that the experience of the World War can serve only as a point of departure — a point already left far behind us.It cannot serve as a basis for the preparation of national defense, a preparation which must be undertaken with an eye to the necessities of the future.

We must also bear in mind this fact: we are faced today with conditions which favor intensive study and wide application of these new weapons, the potentialities of which are unknown; and these conditions are the very ones to which Germany has been relegated. The Allies compelled Germany to disarm and to scrap her standing army. Will she accept patiently this inferior status? Or will she, forced by necessity, look for new weapons to replace the old ones now forbidden to her, and with them wreak her revenge? The fact that Germany leads the world in both fields, chemico-bacteriological and mechanical, must not be lost sight of. Already we can see signs that she is thinking along those lines, that she will apply the intensity, the unswerving purpose which have always distinguished her people, to the development of those new weapons of war. She can do so in the secrecy of her laboratories, where all foreign disarmament control— if any such control was ever effective — is bound to be futile.

Quite apart from what Germany may or may not do, however, it is impossible to ignore the value of these new weapons or to deny their vital role in any preparation for national defense.But in order to make an accurate estimate of the importance of these weapons, we must know exactly what their value is, both in themselves and in relation to the army and navy. Such an estimate is the primary object of this study.

THE NEW POSSIBI LITI ES

As long as man remained tied to the surface of the earth, his activities had to be adapted to the conditions imposed by that surface. War being an activity which necessitates wide movements of forces, the terrain upon which it was fought determined its essential features. The uneven configuration of the land surface presents all kinds of obstacles which hinder movements of solid bodies over it. Hence man has had either to move along the lines of least resistance, or by long and arduous labor surmount the obstacles encountered in the more difficult zones. Thus the surface of the earth gradually became covered with lines of easy transit intersecting at various points, at others separated by zones less easy of access, sometimes impassable.

The sea, on the contrary, being everywhere uniform in character, is equally navigable over all parts of its surface. But because the sea is bound by coast lines, freedom of navigation is often precluded except between points of contact situated on the same coastline or along arbitrary routes under foreign control, to avoid which long journeys around the coasts themselves must be undertaken.

War is a conflict between two wills basically opposed one to the other. On one side is the party who wants to occupy a certain portion of the earth; over against him stands his adversary,the party who intends to oppose that occupation, if necessary by force of arms. The result is war.

The attacking force tries to advance along the lines of least resistance, or easiest accessibility,toward the region he intends to occupy. The defender naturally deploys his forces along the line of the enemy’s advance in an effort to bar his way. The better to oppose the advance of the enemy, he tries to deploy his forces where the terrain is in his favor or along lines of obstacles most difficult to pass. Because these natural obstacles are permanent and unchanging, just as are the rich and fertile — hence most coveted — regions of the earth, certain portions of the earth’s surface seem singled out by destiny to be humanity’s battle grounds for all time.

Since war had to be fought on the surface of the earth, it could be waged only in movements and clashes of forces along lines drawn on its surface. Hence, to win, to gain control of the coveted area, one side had to break through the fortified defensive lines of the other and occupy the area. As making war increasingly required the entire resources of nations, in order to protect themselves from enemy invasion warring nations have been forced to spread out their forces along battle lines constantly extended as the fighting went on, to a point where, as in the last war, the lines extended over practically the whole battlefield, thus barring all troop passage either way.

Behind those lines, or beyond certain distances determined by the maximum range of surface weapons, the civilian populations of the warring nations did not directly feel the war.No enemy offensive could menace them beyond that predetermined distance, so civilian life could be carried on in safety and comparative tranquillity. The battlefield was strictly defined;the armed forces were in a category distinct from civilians, who in their turn were more or less organized to fill the needs of a nation at war. There was even a legal distinction made between combatants and noncombatants. And so, though the World War sharply affected whole nations,it is nonetheless true that only a minority of the peoples involved actually fought and died.The majority went on working in safety and comparative peace to furnish the minority with the sinews of war. This state of affairs arose from the fact that it was impossible to invade the enemy’s territory without first breaking through his defensive lines.

But that situation is a thing of the past; for now it is possible to go far behind the fortified lines of defense without first breaking through them. It is air power which makes this possible.

The airplane has complete freedom of action and direction; it can fly to and from any point of the compass in the shortest time — in a straight line — by any route deemed expedient.Nothing man can do on the surface of the earth can interfere with a plane in flight, moving freely in the third dimension. All the influences which have conditioned and characterized warfare from the beginning are powerless to affect aerial action.

By virtue of this new weapon, the repercussions of war are no longer limited by the farthest artillery range of surface guns, but can be directly felt for hundreds and hundreds of miles over all the lands and seas of nations at war. No longer can areas exist in which life can be lived in safety and tranquillity, nor can the battlefield any longer be limited to actual combatants. On the contrary, the battlefield will be limited only by the boundaries of the nations at war, and all of their citizens will become combatants, since all of them will be exposed to the aerial offensives of the enemy. There will be no distinction any longer between soldiers and civilians. The defenses on land and sea will no longer serve to protect the country behind them; nor can victory on land or sea protect the people from enemy aerial attacks unless that victory insures the destruction, by actual occupation of the enemy’s territory, of all that gives life to his aerial forces.

All of this must inevitably effect a profound change in the form of future wars, because the essential characteristics of those wars will be radically different from those of any previous ones.We may thus be able to understand intuitively how the continuing development of air power,whether in its technical or in its practical aspects, will conversely make for a relative decrease in the effectiveness of surface weapons, in the extent to which these weapons can defend one’s country from the enemy.

The brutal but inescapable conclusion we must draw is this: in face of the technical development of aviation today, in case of war the strongest army we can deploy in the Alps and the strongest navy we can dispose on our seas will prove no effective defense against determined efforts of the enemy to bomb our cities.

THE UPHEAVAL

The World War was a long-drawn-out war which almost completely exhausted both victor and vanquished. This was owing to the technical aspects of the conflict more than to anything else — that is, to new developments in firearms which strongly favored the defensive over the offensive; and, to a lesser degree, to a psychology which could not grasp immediately the advantage conferred on the defensive by the improvement in firearms. Advocates of the offensive were in the saddle everywhere extolling the advantages of the offensive war, but at the same time forgetting that one must have the means to back it up in order to take the offensive successfully. Of the defensive attitude, on the other hand, there was hardly any talk at all,only occasional casual mentions, as though it were a painful subject not to be discussed. This attitude encouraged the belief, held quite generally by military men, that the increased power of firearms favored the offensive rather than the defensive. This belief proved to be an error;the truth was the exact opposite, and clear thinking could have foreseen it, as subsequent war experiences plainly showed.

The truth is that every development or improvement in firearms favors the defensive.Defensive action not only permits the conservation of one’s weapons for a longer time, but also puts them in the best position to increase their efficacy. It is therefore understandable that, in the absolute sense, the more powerful the weapon, the more valuable will be those dispositions which contribute to its preservation and the increase of its efficacy. This is clearly demonstrated by the fact that never before had there been such a widespread and thorough use of systems of defense as in the World War, in which they assumed formidable proportions. And to prove the fact, we have only to consider what those formidable systems of defense, which for a long period during the war formed the main bulwark of the battle line, would have been worth if the infantry and artillery manning them had been armed like those in the time of Gustavus Adolphus. They would have been worth next to nothing.

But with the increased efficacy of firearms, the defensive had both absolute and relative advantages over the offensive. Let us imagine a soldier posted in a trench protected by barbed wire entanglements and the attacking enemy exposed on open ground for one minute; and let us also suppose that both sides are armed with muzzle-loading muskets capable of firing one shot a minute. Then we have the mathematical certainty that for the attacker to reach the trench defended by the single soldier, only two men are necessary, because in the minute of time allowed, only one of the two can be hit and put out of action by the defender. But if both sides are armed with rifles which can fire thirty rounds a minute, to have the same mathematical certainty the trench must be stormed by thirty-one men. All the rounds these men might have fired before attacking would have no bearing on the case if the lone defender is effectively covered by his own barbed-wire trench.

In the first instance one man on the offensive is effectively checkmated by one man on the defensive; in the second instance thirty men are effectively checkmated by one man because the rifle used was thirty times more effective. With this increased power of firearms, the offensive must, in order to win, upset this equilibrium by a preponderance of forces.

In actual fact, during the World War the enormous increase in the power of small-caliber arms made it possible for the defensive to let waves of attacking infantry come close to its own prepared positions and then stop them dead in their tracks; or the defensive could force the offensive, if desperately bent on reaching its objective, to shift its infantry attacks on men in prepared positions and lay down costly artillery barrages of all calibers which literally churned up the very ground, burying its defenders along with it. So that never before were offensive operations so difficult and so costly as during the World War.

But to say that the increased power of new weapons favors the defensive is not to question the indisputable principle that wars can be won only by offensive action. It means simply that, by virtue of increased fire power, offensive operations demand a much larger force proportionately than defensive ones.

Unfortunately, this fact was not realized until late in the war. So during that long conflict attacks were launched without adequate means, attacks which completely failed or only partly succeeded at a great waste of time, money, and men. Because of the inevitable slowness entailed in the process of getting together the enormous quantity of men and materiel to carry them through, these ill-prepared attempts at offensive action succeeded only in wearing down the forces engaged and prolonging the war. And it is certain that if the armies engaged in that struggle had been armed only with muzzle-loading muskets, we should have seen neither reinforced concrete trenches nor barbed-wire entanglements; and the war would have been decided in a few months. Instead, what we saw was a prolonged duel of powerful weapons against even more powerful defense fortresses until, by dint of sheer repeated battering, the fortified defenses were finally crumbled and the heart of the enemy bared. This prolonging of the war saved the day for the Allies simply because it gave them time to procure new allies and fresh troops; but on the other hand it almost completely exhausted both victor and vanquished.

In their war preparations the Germans took into account the value the increased power of firearms might give the defensive. They conceived of war in its most offensive aspect, and so provided themselves with the most adequate means — the 305 and 420 mm. guns — with which to wage war and to clear the road of permanent fortifications as quickly as possible.Thus they began the struggle with decisive offensive action; but when circumstances on the French front forced them to adopt the defensive, they covered their position with a system of defense so thorough and so adequate that it surprised the Allies. It could not possibly have been improvised; it must have been thoroughly worked out and planned long in advance to meet just such eventualities.

Germany had also to consider in her preparations for war the possibility of being compelled to fight on more than one front, and to consider the advantage of a defensive under such circumstances — of holding one front with a minimum of effectives while she struck at the other with her maximum forces. No doubt, therefore, she thoroughly systematized some such plan, and no sooner had circumstances shown the necessity of it than she put it into action.This shows clearly how well aware Germany was of the value of the defensive both in itself and relative to the offensive, even though she held firmly to the principle that victory can be won only by offensive action.

Although the preponderance of forces necessary for the offensive to tip the scale made offensive operations more difficult than defensive ones, yet indirectly the situation worked to the advantage of the offensive by making it possible for the offensive to thin out its own defensive lines and mass the greatest possible force in the sector chosen for attack. All the strategic moves of the Germans can be reduced to this formula: to hold a part of the enemy’s forces with a small force of her own along a well-systematized line of defense, at the same time attacking another part of the enemy’s forces with the largest force she could thus make available. This strategy was often successful over a long period of time.

Caught by surprise, the Allies no sooner saw the German march into the heart of France halted, than they deluded themselves into believing — their lack of defensive preparations notwithstanding — that they could win the war with comparative ease; so, having failed to do at once what should have been done at the beginning of hostilities to insure victory, they were forced to do it in successive stages. In the purely military sense, the war was prolonged by failure to understand the exact nature and demands of modern war. This lack of comprehension produced a series of inconclusive offensives which used up materiel as fast as it was gathered to launch them, thus time and again frittering away that preponderance of forces necessary to upset the equilibrium between the opposing forces which alone could have ended the war sooner.

Though the destruction wrought by the World War was enormous, the nations were able to keep up the struggle for the very reason that the fighting was sporadic and drawn out over a long period of time, so that they could replace their successive material and moral losses and go on throwing all their resources into the struggle until they were exhausted. Never, at any time during the war, was a death-blow struck — a blow which leaves a deep gaping wound and the feeling of imminent death. Instead both sides struck innumerable blows and inflicted many wounds; but the wounds were light ones and always had time to heal. Such wounds, while leaving the body weaker and weaker, still left the patient with the hope of living and recovering strength enough to deal to an equally weakened enemy that last pinprick capable of drawing the last drop of blood. As a matter of fact, the final decision was reached through battles less bloody than earlier ones which had brought only relative results. There is no doubt now that half of the destruction wrought by the war would have been enough if it had been accomplished in three months instead of four years. A quarter of it would have been sufficient if it had been wrought in eight days.

The special character of the World War, then, was shaped by the development of firearms during the last few decades. Now, since the nature of development is dynamic, not static, if there were no new facts to be taken into consideration, the war of the future would have the same general characteristics as the last one, only those characteristics would be accentuated. In other words, in future wars it would be logical to rely upon the continually increasing advantages of the defensive over the offensive, and concomitantly on the still greater difficulty in tipping the scale between the two sides, a necessity if a war is to be won.

If this were the case, protected as we are by a solid frontier of mountains and having no lust for conquest, we should be in an excellent position to face any enemy. With a small force and limited means we could easily provide for the defense of our territory even against attack by greatly superior forces, and rely upon gaining enough time to meet any eventuality of the conflict. But this is not the case; for the new weapons — as we shall see later in this study— reverse this situation by magnifying the advantages of the offensive and at the same time minimizing, if not nullifying, the advantages of the defensive; and, moreover, depriving those who are not fully prepared and ready for instant action of time in which to prepare for defense.No fortifications can possibly offset these new weapons, which can strike mortal blows into the heart of the enemy with lightning speed.

Confronted as we are by this upheaval in the character of war, which encourages nations who lust for conquest and feel neither hesitation nor remorse, it is imperative that we stop and examine calmly, coolly, but searchingly into the question of what is the right path for us to follow in providing for an effective national defense.

THE OFFENSIVE ARM

Because of its independence of surface limitations and its superior speed — superior to any other known means of transportation — the airplane is the offensive weapon par excellence.

The greatest advantage of the offensive is having the initiative in planning operations — that is, being free to choose the point of attack and able to shift its maximum striking forces; whereas the enemy, on the defensive and not knowing the direction of the attack, is compelled to spread his forces thinly to cover all possible points of attack along his line of defense, relying upon being able to shift them in time to the sector actually attacked as soon as the intentions of the offensive are known. In that fact lies essentially the whole game of war tactics and strategy.

From this it is obvious that those nations which have the means to mass their forces rapidly and strike at whatever point they choose of the enemy’s forces and supply lines are the nations which have the greatest potential offensive power. In the days when war was fought with small,light, fast-moving bodies of forces, it offered a wide field for tactical and strategic moves; but as the masses engaged grew larger, the playground diminished in size and the game became more restricted. During the World War the masses involved were enormous, and extremely slow and heavy; as a consequence their movements were reduced to a minimum and the war as a whole became a direct, brutal clash between opposite forces.

The airplane, in contrast, can fly in any direction with equal facility and faster than any other means of conveyance. A plane based at point A, for example, is a potential threat to all surface points within a circle having A for its center and a radius of hundreds of miles for its field of action. Planes based anywhere on the surface of this same circle can simultaneously converge in mass on point A. Therefore, an aerial force is a threat to all points within its radius of action,its units operating from their separate bases and converging in mass for the attack on the designated target faster than with any other means so far known. For this reason air power is a weapon superlatively adapted to offensive operations, because it strikes suddenly and gives the enemy no time to parry the blow by calling up reinforcements.

The striking power of the airplane is, in fact, so great that it results in a paradox: for its own protection it needs a greater striking force for defense than for attack. For example, let us suppose that the enemy has an air force with the offensive capacity of X. Even if its bases are scattered, such a force can easily concentrate its action, gradually or however it sees fit, on any number of objectives within its radius of action. To be exact, let us say that there are twenty of these objectives. In this case, in order to defend ourselves from what force X can do, we are obliged to station near each of these twenty objectives a defensive force corresponding to force X,in all twenty times as many planes as the enemy has. So that to defend ourselves we would need a minimum aerial force twenty times as large as the attacking force of the enemy — a solution of the problem which partakes of the absurd because the airplane is not adaptable to defense,being pre-eminently an offensive weapon.

The suddenness with which this weapon appeared during the last war made it impossible to study thoroughly the problems posed by its use as a combat weapon. Aerial offensives were instinctively and empirically met by anti-aerial defense alone, whether operating in the air or from the ground. Thus were born antiaircraft guns, and reconnaissance and pursuit planes. But subsequent experience demonstrated that all these means of defense were inadequate, despite the fact that aerial offensives in the last war were of minor importance, haphazardly planned and executed. Every time an aerial offensive was carried out resolutely, it accomplished its purpose. Venice was bombed repeatedly from beginning to end of the war; Treviso was almost razed under our very eyes; and Padua had to be abandoned by the Supreme Command. In other countries, both Allied and enemy, the same thing happened.

In spite of the most elaborate system of signals, if our pursuit squadrons were not already in the air when the enemy reached its objective — and obviously they could not remain in the air continuously — they could seldom take off in time to prevent the enemy from dropping his load of bombs on his chosen targets. There was artillery fire, but it seldom hit the mark; when it did, it scored by chance, as a sparrow might be hit by chance with a rifle bullet. Antiaircraft guns, too, went into action, giving chase through the streets of towns and cities and through the open country in their effort to hit planes diving here, there, and everywhere at will. They behaved much like a man trying to catch a homing pigeon by following him on a bicycle! In the descending curve of its trajectory, artillery fire was metamorphosed into projectiles falling from above. And all of this defensive fire amounted to nothing but a useless dispersion of enormous quantities of our national resources, sometimes wasted on the notion of preventing, not an actual attack, but a possible one! How many guns lay waiting month after month, even years,mouths gaping to the sky, on the watch for an attack which never came! How many pursuit planes immobilized men and materials without ever getting a chance to defend anything! How many people, after staring long and vainly at the sky for the enemy to appear, went soundly and happily to sleep!

I do not know whether an account has ever been drawn up of the weapons and resources scattered over the countryside for aerial defense; but there is no doubt that the total must have been very large. And all that effort, all those resources, so prodigally wasted, could have been profitably used for other purposes.

This dispersion of means, contrary to the fundamental principles of war and to a sound economy of warfare, was caused, as I have already said, by the disorientation produced by the suddenness with which air power came into being, which made for a fallacious concept of defense against it. When a mad dog runs amok in a village, the villagers do not post themselves separately on their own doorsteps, each man armed with a club, waiting on the pleasure of the dog to make an appearance and be killed. That kind of behavior would interrupt their work, but would not prevent the animal from biting someone. No villagers would behave that way. They would gather in groups of three, four, or more of the bolder spirits and go after the dog, track it to its lair, and there kill it.

Similarly, there is no practical way to prevent the enemy from attacking us with his air force except to destroy his air power before he has a chance to strike at us. It is now axiomatic — and has long been so — that coastlines are defended from naval attacks, not by dispersing ships and guns along their whole extent, but by conquering the command of the seas; that is, by preventing the enemy from navigating. The surface of the earth is the coastline of the air. The conditions pertaining to both elements, the air and the sea, are analogous; so that the surface of the earth,both solid and liquid, should be defended from aerial attack, not by scattering guns and planes over its whole extent, but by preventing the enemy from flying. In other words, by“conquering the command of the air.”

This is the logical and rational concept which should be recognized, even for simple defense— namely, to prevent the enemy from flying or from carrying out any aerial action at all.

Conquering the command of the air implies positive action — that is, offensive and not defensive action, the very action best suited to air power.

THE MAGNITUDE OF AERIAL OFFENSIVES

Some conception of the magnitude aerial offensives may reach in the future is essential to an evaluation of the command of the air, a conception which the World War can clarify for us in part.

Aerial bombs have only to fall on their target to accomplish their purpose; hence their construction does not require as much metal as is needed in artillery shells. If bombs containing high explosives require a large amount of metal in proportion to their internal charge in order to ensure an effective explosion, the proportion of metal in bombs containing incendiaries or poison gases may be reduced to a minimum. We may be not far off if we figure roughly the proportion of metal in them at 50 per cent of their total weight. The construction of aerial bombs does not call for high-grade steel, other special metals, nor for precision work. What it does demand is that the active ingredients of the bombs — the explosives, incendiaries, and poison gases — have the maximum efficacy, and that research be directed to this end.

Aerial bombardment can certainly never hope to attain the accuracy of artillery fire; but this is an unimportant point because such accuracy is unnecessary. Except in unusual cases,the targets of artillery fire are designed to withstand just such fire; but the targets of aerial bombardment are ill-prepared to endure such onslaught. Bombing objectives should always be large; small targets are unimportant and do not merit our attention here.

The guiding principle of bombing actions should be this: the objective must be destroyed completely in one attack, making further attack on the same target unnecessary. Reaching an objective is an aerial operation which always involves a certain amount of risk and should be undertaken once only. The complete destruction of the objective has moral and material effects, the repercussions of which may be tremendous. To give us some idea of the extent of these repercussions, we need only envision what would go on among the civilian population of congested cities once the enemy announced that he would bomb such centers relentlessly,making no distinction between military and non-military objectives.

In general, aerial offensives will be directed against such targets as peacetime industrial and commercial establishments; important buildings, private and public; transportation arteries and centers; and certain designated areas of civilian population as well. To destroy these targets three kinds of bombs are needed — explosive, incendiary, and poison gas — apportioned as the situation may require. The explosives will demolish the target, the incendiaries set fire to it, and the poison-gas bombs prevent fire fighters from extinguishing the fires.

Gas attacks must be so planned as to leave the target permeated with gas which will last over a period of time, whole days, indeed, a result which can be attained either by the quality of the gases used or by using bombs with varying delayed-action fuses. It is easy to see how the use of this method, even with limited supplies of explosive and incendiary bombs, could completely wreck large areas of population and their transit lines during crucial periods of time when such action might prove strategically invaluable.

As an illustration of the magnitude of aerial power, let us assume that 100 kilograms of active material is capable of destroying the area of a circle 25 meters in radius. This supposition is consistent with present practice. Then, in order to extend the destructive action of this active material over a surface 500 meters in diameter, 100 times 100 kilograms, or 10 tons, will be required. Now, 10 tons of active material requires 10 tons of metal casing or shell. Today there are airplanes which can easily carry 2 tons of bombs in addition to their crews; so 10 such planes could carry all the bombs necessary to destroy everything within this circle of 500 meters diameter. To obtain this result it is necessary only to train the crews of ten airplanes to drop their bombs as uniformly as possible over that area.

This gives us the concept of the basic unit of power needed for effective bombing operations;namely, the unit of bombardment must have the potentiality to destroy any target on a given surface. In my opinion, the extent of this surface should be exactly the area of a circle 500 meters in diameter. Then, if the above assumptions are correct, this unit should be 10 planes, each capable of carrying 2 tons of bombs. The exact ratio, however, can well be left to experience.

As I said, bombing pilots should be trained to spread their loads over such surfaces as uniformly as possible, releasing their bombs from a medium altitude of, say, 3,000 meters.This dissemination can be accomplished by artificially extending — by variations of sighting data — the natural rose-shaped aim of the squadron formation. If a specified surface contains very vulnerable targets, the area can be extended beyond the 500-meter diameter simply by increasing the number of planes taking part. Conversely, surfaces containing targets more difficult to destroy can be contracted by reducing the number of planes.

But these details are of secondary importance. Of prime importance is the fact that the adoption of such tactics makes the bomber a definite and precise offensive power, no longer a vague, indeterminate one.

When, on the other hand, the surface of a specified objective is smaller, but nevertheless important for military reasons, it should be so designated on the map. It makes no difference if a few bombs go wide of the mark during the attack. But if an objective with a surface larger than 500 meters in diameter is marked for attack, the entire area should be so designated. If the aim is to destroy everything on a surface of, say, 1,000 meters, it is sufficient to divide the target into separate zones and attack with separate but coordinated squadrons of planes, with 9 squadrons if the area is 1,500 meters, with 16 squadrons if 2,000 meters, and so forth. Such bombing expeditions, however, cannot be undertaken successfully unless they are directed against very large centers of civilian population. In fact, we have no difficulty in imagining what would happen when areas of 500 to 2,000 meters in diameter in the center of large cities such as London, Paris, or Rome were being unmercifully bombed.4 With 1,000 bombers of the type described — an actual type in use today, not a hypothetical type in some blueprint of the future — with their necessary maintenance and replacements for daily losses, 100 such operating squadrons can be constituted. Operating 50 of these daily, such an aerial force in the hands of those who know how to use it could destroy 50 such centers every day. This is an offensive power so far superior to any other offensive means known that the power of the latter is negligible in comparison.

As a matter of fact, this same offensive power, the possibility of which was not even dreamed of fifteen years ago, is increasing daily, precisely because the building and development of large, heavy planes goes on all the time. The same thing is true of new explosives, incendiaries,and especially poison gases. What could an army do faced with an offensive power like that, its lines of communication cut, its supply depots burned or blown up, its arsenals and auxiliaries destroyed? What could a navy do when it could no longer take refuge in its own ports, when its bases were burned or blown up, its arsenals and auxiliaries destroyed? How could a country go on living and working under this constant threat, oppressed by the nightmare of imminent destruction and death? How indeed! We should always keep in mind that aerial offensives can be directed not only against objectives of least physical resistance, but against those of least moral resistance as well. For instance, an infantry regiment in a shattered trench may still be capable of some resistance even after losing two-thirds of its effectives; but when the working personnel of a factory sees one of its machine shops destroyed, even with a minimum loss of life,it quickly breaks up and the plant ceases to function.

All this should be kept in mind when we wish to estimate the potential power of aerial offensives possible even today. To have command of the air means to be in a position to wield offensive power so great it defies human imagination. It means to be able to cut an enemy’s army and navy off from their bases of operation and nullify their chances of winning the war. It means complete protection of one’s own country, the efficient operation of one’s army and navy,and peace of mind to live and work in safety. In short, it means to be in a position to win. To be defeated in the air, on the other hand, is finally to be defeated and to be at the mercy of the enemy, with no chance at all of defending oneself, compelled to accept whatever terms he sees fit to dictate.

This is the meaning of the“command of the air.”

NOTE I: The municipality of Treviso has published a pamphlet entitled“The Martyrdom of Treviso,” which may serve as an illustration of what I have said above. In 32 attacks by Austro Hungarian fliers from April 1916 to the end of October 1918, approximately 1,500 bombs were dropped in an area about 1 kilometer square. Calculating the average weight of each bomb at 50 kilograms — very likely it was less — a total of 75 tons of bombs was dropped on Treviso in 2 years of war.

On the basis of the approximate calculation I personally made, the diameter of Treviso at its widest periphery being about 1 kilometer, it would take 4 squadrons of 10 planes each, or 40 planes in all, each carrying 2 tons of bombs, or 80 tons in all, to wreak that much destruction.

If we look at the map in“The Martyrdom of Treviso” which shows the distribution of bomb hits and the photographic reproductions of the damage done, we can readily see that if those 75 or 80 tons of bombs, correctly apportioned among explosive, incendiary, and poison-gas types,had been dropped in one day, Treviso would have been completely destroyed and very few of her inhabitants saved. What made it possible for Treviso to escape total destruction and remain on the map in spite of the grave danger to which it was exposed, and to evacuate the population with the loss of only 30 civilian dead and 50 wounded in the very first bombings, is this: during each attack an average of only 50 bombs were dropped, thus allowing time between attacks to smother the fires started during the attacks.

But during all that time nothing effective was done by our aerial defense forces to prevent the bombings except to take note of the places bombed; so the attacks went on until the very end of October 1918, or until the Armistice of November 3, in spite of our claim, especially toward the end of the war, to the command of the air.

NOTE II: The English fleet, the most powerful in the world today, consists of 30 battleships totaling 792,496 tons, exclusive of her smaller units. The weight of their broadsides, every gun firing one round, is 194,931 kilograms, or about 195 tons, each broadside averaging 6.5 tons per battleship.

In contrast, a squadron of 10 planes carrying 2 tons of bombs each, can in a single flight drop 20 tons of bombs, or something more than the broadsides of 3 English battleships. Similarly,an aerial fleet of 1,000 planes carrying 2 tons each can drop 2,000 tons of bombs, or something more than the whole English fleet of 30 battleships firing 10 rounds with all guns blazing. A thousand such planes, estimating the cost of each at a million lire, would be a round billion lire,or about the cost of a single dreadnought.

Besides the cost, there is another great difference between sea power and air power. The English fleet can fire its broadsides only against another fleet willing to engage in battle, or against stationary targets along seacoasts. An aerial fleet, on the other hand, can carry out bombing attacks against targets which have no way of retaliating or of putting up any self defense at all, and which may be located anywhere on the surface of sea or land.

Moreover, we may soon see the construction of bombers with a capacity of more than 10 tons of effective load, or of a bomb load equal to or even surpassing the broadside of a battleship.And it is also probable that in the event of a duel between a battleship and airplanes, the battleship, with her heavy guns unable to fire at a vertical angle, would get the worst of it. And even if her guns could fire at such an angle, it would be almost impossible to hit a fast-moving plane diving almost vertically — a plane can do just that — at the ship. Recent experiments conducted in the United States and in France seem to furnish conclusive proof of this.

But apart from that, the figures presented in this note should at least give us a more concrete idea of the magnitude of air power and the simplicity of the means needed to effectuate it.

THE COMMAND OF THE AIR

To have command of the air means to be in a position to prevent the enemy from flying while retaining the ability to fly oneself. Planes capable of carrying moderately heavy loads of bombs already exist, and the construction of enough of them for national defense would not require exceptional resources. The active ingredients of bombs or projectiles, the explosives,the incendiaries, the poison gases, are already being produced. An aerial fleet capable of dumping hundreds of tons of such bombs can easily be organized; therefore, the striking force and magnitude of aerial offensives, considered from the standpoint of either material or moral significance, is far more effective than those of any other offensive yet known. A nation which has command of the air is in a position to protect its own territory from enemy aerial attack and even to put a halt to the enemy’s auxiliary actions in support of his land and sea operations,leaving him powerless to do much of anything. Such offensive actions can not only cut off an opponent’s army and navy from their bases of operations, but can also bomb the interior of the enemy’s country so devastatingly that the physical and moral resistance of the people would also collapse.

All this is a present possibility, not one in the distant future. And the fact that this possibility exists, proclaims aloud for anyone to understand that to have command of the air is to have victory. Without this command, one’s portion is defeat and the acceptance of whatever terms the victor is pleased to impose. Reasoning from the facts along the lines of logic, this is the conclusion we have reached. But since this conclusion applies to matters of very great practical importance, and since it is sharply at variance with the accepted way of looking at things, it behooves us to stop and amplify our statement before going on.

When conclusions are reached by reasoning with strict adherence to logic from actual verifiable facts, those conclusions ought to be accepted as valid even if they seem strange and radical, in direct contradiction to conventional thought patterns or fixed habits of mind based upon other facts, equally positive and verifiable to be sure, but entirely different in nature. To come to any other conclusion would be to deny reason itself. It would be like the reasoning of a peasant who insists upon cultivating his land exactly as his father and grandfather did before him, despite the fact that by using chemical fertilizers and modern machinery he could double or treble his harvest. Such old-fashioned, die-hard perverseness gets him nothing except a handicap in the market place.

Twelve years ago, when the very first airplanes began to hedgehop between field and air,hardly what we would call flying at all today, I began to preach the value of command of the air.From that day to this I have done my level best to call attention to this new weapon of warfare. I argued that the airplane should be the third brother of the army and navy. I argued that the day would come when thousands of military planes would ply the air under an independent Ministry of the Air. I argued that the dirigible and other lighter-than-air ships would give way before the superiority of the plane. And everything I argued for then has come true just as I predicted it in 1909.

I did not prophesy then, and I do not prophesy now. All I did then was to examine the new problem posed by the existence of the new arm and reason from verifiable data; but I did not hesitate to follow up the implications of the conclusions I reached, in spite of the fact that then,as now, they may have sounded paradoxical. I was convinced with mathematical certainty that the facts would prove me right.

When, by the exercise of cold logic and mathematical calculation, someone was able to find out the existence of an unknown planet and furnish an astronomer with all the data necessary for its discovery; when by mathematical reasoning the electro-magnetic waves were discovered,thus furnishing Hertz the means with which to carry on his experiments — then we too should have faith in the validity of human reasoning, at least to the extent that the astronomer and Hertz had faith in it. And how much more abstruse their reasonings were than the reasoning I am attempting here!

At this point I ask my readers to stop with me and consider what I have been saying —the arguments are worth while — so that each may come to his own conclusion about it. The problem does not admit of partial solution. It is right or it is not right.

What I have to say is this: In the preparations for national defense we have to follow an entirely new course because the character of future wars is going to be entirely different from the character of past wars.

I say: The World War was only a point on the graph curve showing the evolution of the character of war; at that point the graph curve makes a sharp swerve showing the influence of entirely new factors. For this reason clinging to the past will teach us nothing useful for the future, for that future will be radically different from anything that has gone before. The future must be approached from a new angle.

I say: If these facts are not given careful consideration, the country will have to make great sacrifices in an effort to bring its defense up to date; but even these sacrifices will be of little use, for the defenses could not possibly meet the demands of modern military requirements.This can be denied only by refuting my argument.

I ask again: Is it true or is it not true that the strongest army and navy we could muster would be powerless to prevent a determined, well-prepared enemy from cutting them off from their bases of operation and from spreading terror and havoc over the whole country?

We can answer,“No, it is not true,” to this question only if we have no intention of providing ourselves with suitable means, in addition to those of the army and navy, with which to meet any such eventuality. But I, for one, have long been answering this question with a categorical“Yes,it is true”; and it is because I am convinced of the imminence of such an eventuality that I have deeply pondered the problem posed by the new forms and weapons of war.

NOTE: In 1909 I wrote:“To us who until now have been inexorably bound to the surface of the earth; to us who have smiled superciliously, almost with compassion, at the efforts of a few intrepid pioneers whom we thought deluded with visions of the impossible, but who proved to be the real seers; to us who have only armies and navies, it must seem strange that the sky, too,is about to become another battlefield no less important than the battlefields on land and sea.But from now on we had better get accustomed to this idea and prepare ourselves for the new conflicts to come. If there are nations which can exist untouched by the sea, there are certainly none which exist without the breath of air. In the future, then, we shall have three instead of two separate and well-defined fields of battle; and, though in each of them the conflict will be carried on with different weapons, they will still have to be coordinated toward a common goal,which will always remain the same — namely, to win.

“We are fully conscious today of the importance of having command of the seas, but soon the command of the air will be no less important because only by having such a command —and only then — can we make use of the advantages made possible by aerial observation and the ability to see targets clearly — advantages which we shall not be able fully to enjoy until we have the aerial power to keep the enemy grounded. The struggle for the command of the air will be bitter; and the so-called civilized nations will strive to forge the most telling means to wage the conflict. But any conflict, other things being equal, is ultimately decided by weight of numbers; so the race for supremacy will go on without cease, only checked now and then by economic contingencies. By virtue of this race for air supremacy, air fleets will grow in importance as they get larger.

“The army and navy should not then see in the airplane merely an auxiliary arm of limited usefulness. They should rather see in the plane a third brother, younger of course, of the powerful family of War.” ［“I problemi dell’ aeronavigazione,” by Major G. Douhet; from the newspaper La preparazione, Rome, 1910.］

Now, after the experiences of the World War, I find no need to modify by a single word what I wrote eleven years ago. Time has confirmed my deductions, even though the concept of the command of the air has not yet been realized in practice. For that I am not to blame. But anyhow today — it could not possibly be otherwise — those ideas are rapidly gaining ground —especially outside of Italy.

THE EXTREME CONSEQUENCES

To conquer the command of the air means victory; to be beaten in the air means defeat and acceptance of whatever terms the enemy may be pleased to impose. The truth of this affirmation,which for me is an axiom in itself, will become increasingly apparent to readers who will take the trouble to follow this study, wherein I hope to make it completely clear.

From this axiom we come immediately to this first corollary: In order to assure an adequate national defense, it is necessary — and sufficient — to be in a position in case of war to conquer the command of the air. And from that we arrive at this second corollary: All that a nation does to assure her own defense should have as its aim procuring for herself those means which, in case of war, are most effective for the conquest of the command of the air.

Any effort, any action, or any resources diverted from this essential aim makes conquering the command of the air that much less probable; and it makes defeat in case of war that much more probable. Any diversion from this primary purpose is an error. In order to conquer the air, it is necessary to deprive the enemy of all means of flying, by striking at him in the air, at his bases of operation, or at his production centers — in short, wherever those means are to be found. This kind of destruction can be accomplished only in the air or in the interior of the enemy’s country. It can therefore be accomplished only by aerial means, to the exclusion of army and navy weapons. Therefore, the command of the air cannot be conquered except by an adequate aerial force. From this affirmation and the above-mentioned first corollary, we may draw an inference of practical value; namely: An adequate national defense cannot be assured except by an aerial force capable in case of war of conquering the command of the air. To be sure, this statement is directly opposed to the prevailing conception of national defense, and it puts the air arm first in order of importance. Nevertheless, to deny this affirmation, we must also deny the value of command of the air. To break away from the past is disturbing; but so is man’s conquest of space disturbing.

As I have pointed out, this conclusion means the superseding of traditional values by new ones not yet fully realized. Up to this time the army and navy have been the predominant forces, and no one questioned that supremacy. Space was closed to man. But there is no a priori reason why the air arm cannot become the predominant power in its relations with surface forces. In examining these relations, we come to the conclusion that the air force is destined to predominate over both land and sea forces; this because their radius of offensive action is limited in comparison to the vastly greater radius of the air force.

As I said, we find ourselves now at a particular point in the curve of the evolution of war.After this point the curve drops off abruptly in a new direction, breaking off all continuity with the past. Therefore, if we have a tendency to deviate as little as possible from the beaten path,we will find ourselves diverging from reality, and we will wind up far removed from the realities of our time. To catch up with things as they are, we must change our course sharply and follow reality itself. If reason, common sense, and the facts themselves tell us that the army and navy are declining in importance as compared with air power, we are doing a disservice to our own defense preparations when we insist upon crediting the army and navy with fictitious values which have no basis in actual fact.

Nature does not progress by leaps and bounds — still less does man. I do not imagine that between today and tomorrow the army and navy will be abolished and only the air force increased.

For the present I ask only that we give the air arm the importance it deserves — in Italy we are far from doing that — and that during the transition period we adopt the following modest program: A progressive decrease of land and sea forces, accompanied by a corresponding increase of aerial forces until they are strong enough to conquer the command of the air. This is a program which will approach nearer and nearer reality as we grow firmer in promoting it.

Victory smiles upon those who anticipate the changes in the character of war, not upon those who wait to adapt themselves after the changes occur. In this period of rapid transition from one form to another, those who daringly take to the new road first will enjoy the incalculable advantages of the new means of war over the old. This new character of war, emphasizing the advantages of the offensive, will surely make for swift, crushing decisions on the battlefield.Those nations who are caught unprepared for the coming war will find, when war breaks out,not only that it is too late for them to get ready for it, but that they cannot even get the drift of it.Those who are ready first not only will win quickly, but will win with the fewest sacrifices and the minimum expenditure of means. So that, when this change is completed, though decisions in the field will be swift, the actual war will be fought with increasingly formidable air forces. But during the period of transition a limited force will be adequate to checkmate any opponent’s army and navy.

If we must wait to be convinced of this until someone else sets us an example, we will be left behind; and to be left behind during this period means to be defeated in case of war. And, as I have already pointed out, that, ironically enough, is just what is happening now. In an effort to safeguard themselves against Germany’s possible thirst for revenge, the Allies forced her along the surest road toward accomplishing it. It is a fact that Germany, forced to disarm on land and sea, will be driven to arm in the air. As we shall see, an air force capable of conquering the command of the air, especially during this transition period, requires comparatively limited means, a small personnel, and modest resources; and all of this can be quietly disposed without awakening the attention of potential enemies. At the slightest chafing of the yoke imposed upon her by the Allies, the inner drive to be free will surely push Germany along the new road.This new road is an economic road which makes it feasible for us to provide for national defense with a limited expenditure of energy and resources once the respective weapons of air,land, and sea are properly evaluated. We remember that in England there have been Admirals of the Fleet who questioned the value of battleships versus airplanes; and we remember, too, that in America tests have been made which demonstrated that under certain conditions planes can sink armored ships.

Now we have reached the hour when we can no longer ignore this problem, which, in the interest of national defense, we should face squarely.

INDEPENDENT AIR FORCE AND AUXI LIARY AVIATION

Surveying the problem of national defense in outline, with particular reference to the aerial phase, we have emphasized aerial independence of surface forces and rapidity of movement;and we reached this conclusion: An adequate national defense cannot be assured except by an aerial force capable in case of war of conquering the command of the air. We have seen also that, in order to conquer the command of the air, all aerial means of the enemy must be destroyed whether in air combat, at their bases and airports, or in their production centers;in short, wherever they may be found or produced. And we have noted that neither the army nor the navy can help in any way in this work of destruction. The natural consequence of this situation is that an aerial force capable of conquering the command of the air is, by the very nature of things, organically self-sufficient and independent of land and sea forces in its operations. For the sake of simplicity, I shall hereafter refer to all those aerial means which,taken together, constitute an aerial force capable of conquering the command of the air, by the term, Independent Air Force. The foregoing conclusion may thus be stated: National defense can be assured only by an Independent Air Force of adequate power.

At present the only military use made of airplanes is to assist the operations of land and sea forces; and for this reason they are under the commands of the army and the navy. So far, an aerial force able to command the air does not exist anywhere in the world. If there were one,granting the uniformity of the air extending over land and sea alike, it could not depend for its being or for its operation on either the army or the navy, because such dependency would be an arbitrary one which, by forcing the Independent Air Force to divide its forces, would fail to fill the true needs of the situation. There are planes at present under the direct command of land and sea forces. An example is the observation plane, whose function is to direct artillery fire —a function, by the way, which is not essentially aerial; it would be performed by other means if aviation were not yet invented. Other examples are the bombing and pursuit specialties, which,while not operating directly under military and naval command, are nonetheless dependent upon them. The primary function of planes under direct army command is, naturally, the furthering of specifically army aims; of those under navy command, furthering specifically navy aims. In like manner, pursuit squadrons under army command have the specific duty of policing the sky above the land surface; those under navy command, of policing the sky over the sea surface.

In this situation we feel something which offends our sense of fitness. In face of this state of things, we can see clearly how easy a time a well-organized enemy bent on conquering the command of the air would have, and how helpless these auxiliary aerial means employed by the army and navy would be, confronted by an enemy Independent Air Force bent on conquest,inasmuch as no organized opposition would stand in his way. It is only natural that the army and navy should wish to be provided with aerial auxiliaries to assist their operations. But such aerial means, which integrate the separate operations of those two branches of the service, are nothing more than an extension of the army and navy. They cannot possibly be considered to constitute a real air force. Observation planes directing artillery fire are useful observers in aerial form, no more.

That fact is so self-evident that in our discussion of aerial warfare we have come to the inescapable conclusion that an Independent Air Force functioning completely independent of the army and the navy is of paramount importance.

When, a few years ago, we first encountered the term“flying service,” it seemed a real triumph for the new instrument of war. But it only seemed so; for the term“flying service”expresses only a bond, inasmuch as a“service” is a mere part of a whole, which is the only entity which can be considered really independent. It is only when we arrive at the term“Independent Air Force” that we perceive an entity capable of fighting on the new battlefield, where neither army nor navy can take any part. Planes operating under command of the army or navy can be considered as no more than auxiliary weapons; so, for the sake of simplicity, I shall refer to them from now on as“auxiliary aviation of the army and navy.”

Up to this point I have spoken of aerial means of warfare in general terms only, because I thought best to introduce the problem along general lines at the beginning of the book. But in fact aviation falls into two major categories, lighter-than-air and heavier-than-air ships,or dirigibles and airplanes. I should explain, for the sake of clarity, that from now on I shall confine myself to the heavier-than-air category, airplanes, as the only kind suitable for warfare.