# Aircraft in Warfare (1916)/Chapter 15

CHAPTER XV.
(December 11th, 1914)
THE COMMAND OF THE AIR AND ITS LIMITATIONS. INTERNATIONAL QUESTIONS RELATING TO AIRCRAFT IN WAR.
§ 101. The Command of the Air, and its Limitations. The term "command of the air" can never be taken to carry a meaning so wide or far-reaching, or in any sense so comprehensive, as that understood when we speak of the "command of the sea." Sea-power has its origin and secret in the fact that (as rightly insisted by Mahan) the seas control the main highways of international commerce and communication; thus sea-power is necessarily world-power. It would not, strictly speaking, be true to say that the command of the sea essentially involves world-wide supremacy; but so far as a navy is provided with fully equipped bases, so far will its power extend in its plenitude. It has sometimes been rashly assumed by writers that in the future air-power is not only going to exercise an influence as wide-spread and decisive as sea-power, but is, in fact, about to take a superior position, and that the latter will lose some of its present character and importance. No such conclusion can at present be justified. It is, of course, to-day considered bad form to call any engineering project impossible; but in view of the fact that, after making every reasonable allowance for possible developments, the maximum distance that can be flown by an aeroplane without replenishment is less than 2,000 miles, it is clear that the range or radius of action of an air fleet must be ​regarded as permanently imposing strict limitations on its employment. The large airship, even should it be found to be of greater military or naval importance than suggested in the present volume, is scarcely likely to be better situated, and suffers from the not inconsiderable disadvantage of requiring accommodation of an elaborate and expensive kind. Hence we see that the "command of the air" is, from a world standpoint, a local condition. It might conceivably be secured and asserted by a European Power over half the continent of Europe, or the whole of the south and east of the African continent might be dominated by air fleets having their bases in Egypt and other territory in British occupation. Even this, however, is looking a great way ahead. For the time being we may take it that the policy of any one of the Great Powers in time of peace will be to secure unquestioned supremacy within its own territorial limits, with such bases in the vicinity of its coast lines and frontiers as will suffice to ensure the respect of hostile aircraft in the event of an outbreak of war. When a state of war exists, the task of an air fleet will be to maintain its air supremacy at home, and to extend and carry the command of the air over land or water in support of the Army and Navy, wherever operating. Hence the Aeronautical Force is not to be considered as a new kind of Navy, or otherwise as a self-contained Service to which large-scale independent duties can be assigned; it is definitely, in the words of our title, a new or Fourth Arm.
§ 102. Neutral Aircraft. International Regulations. It has been believed from the earliest days of the modern aeronautical movement that the military, (and naval) uses of the flying-machine would prove to be one of the most important of its initial applications. This view has been more than justified, so much so ​that to-day there is scarcely a machine that "takes the air" in Europe which is not on Service duty. This fact probably the most ardent supporter of the military usage of the flying-machine would have scarcely ventured to predict prior to the outbreak of hostilities. Certainly, if five or six years ago anyone had been bold enough to assert that at the beginning of the year 1915 there would be scarcely a machine flying in Europe on other than military duty, it would have sounded incredible. That the present situation is not representative of the future in this respect we may take for granted. On the other hand, it is becoming clear that we may quite dismiss from our minds any general usage of the air as a commercial highway; the traffic in merchandise which will be air-borne will never become a great percentage of the world's total.
We may anticipate that lines will be established for the rapid conveyance of mails, and to some extent we may look to the development of passenger services in different parts of the world. But for the time being the inconvenient (and, in the case of shipping, contentious) question as to the rights of neutrals in the air can scarcely be said to have been established; commercial usage of the air is virtually non-existent.
The obligations imposed by international law and convention on both belligerents and neutrals are, at the best, of an arbitrary and makeshift character; it is doubtful whether anything is to be gained by attempting to lay down a code or set of rules to control a form of locomotion, in its application to warfare, when so little experience is available. However, the author has had a book placed in his hands (published early in 1914) on "Aircraft in War," in which the whole contents, from cover to cover, relate to nothing but the international aspect of the subject and to rival codes of proposed ​"legislation." It seems, therefore, that this side of the subject requires discussion. Without wishing to belittle work of the type in question, it may certainly be said that the discussion of anything more than the barest generalities of the subject can only be time and effort wasted. A new Arm requires to work out its own salvation in warfare, and the machine which has won for itself and mankind the freedom of the air is not to have its future proscribed or fettered by the scratchings of an unofficial quill.
§ 103. Belligerent Aircraft and the Rights and Obligations of Neutrals. A question which appears likely to lead to great trouble in practice is the propriety of belligerent aircraft operating over the territory of a neutral Power. Without discussing such academic subjects as the territorial sovereignty of the air, it seems clear that eventually neither belligerent can be prevented from passing over neutral territory except by the air forces and counter-air forces of the neutral Power in question. If such Power should elect not to use his forces to prevent such violation of his territorial air, it will be impossible in practice to make him do so or hold him responsible. Beyond this, if the neutral Power should subsequently make claim against a belligerent for using his air, it is difficult to see how any such claim could have more ground than an ordinary civil claim for trespass, in which the only admissible basis of an award is for damage done. If the aircraft has flown at reasonable altitude and has done no injury by dropping anything, or by gun-fire, it is difficult to see how any claim could be substantiated. If the neutral Power should elect to employ his aircraft and counter aircraft artillery to assert a presumed right to his territorial air, he not only puts himself to very considerable expense and inconvenience, but at the best ​his efforts are unlikely to be wholly effective; in thick weather the whole of a belligerent air fleet might pass over his territory without once being sighted. Hence it will be possible that at any time he may be plausibly accused of favouring one side or the other, and thus find himself in difficulties of a diplomatic kind far worse than would have been possible had he left his air undefended. A host of other difficulties spring into one's mind in connection with the defence of territorial air by a neutral Power; aircraft may encounter above the clouds: a belligerent fleet and the neutral air-sentry force. How shall they decide in what way to act? They cannot stand still and hold a palaver whilst the matter is tested by a plumb-line. Clearly any attempt to enforce neutrality in territorial air would be more likely to drag the neutral Power into the war on one side or the other than a rigid abstinence from interference; and since this is one of the most important contingencies to be guarded against, it seems evident that, as a matter of expediency, the rights (if they be admitted) of neutrals over their territorial air should be regarded as not involving any obligation of action against belligerent aircraft. On the other hand, it is equally clear that the ordinary powers of enforcing restrictions in such matters as flying over prohibited areas, etc., will in nowise be weakened by the existence of a state of war, and neither belligerent will have cause for complaint if his aircraft, after due warning, should be fired upon. In brief, whilst it would appear to be impossible to deny the right to a neutral of chasing away—or, if necessary, even of destroying—belligerent aircraft if found in occupation of territorial air, it would appear to be equally impossible to impose the duty of doing so as an obligation. A ​corollary to this would appear to be that the use of a neutral's territorial air will only become a violation of neutrality if persisted in in the presence of aircraft or air forces of the neutral Power. Put in a few words, the position, as above, is in every way analogous to the ordinary law of trespass; the owner is entitled to turn the trespasser off, using only such force as is necessary, and can claim damages only on account of actual injury sustained.
§ 104. Other International Questions Relating to Aircraft. Distinctive Marks. It has been suggested, or stated, by most previous writers on the subject that aircraft will be required to carry a distinctive mark or colours, indicating their nationality and their character as military or belligerent—i.e., not civilian—machines. This view is clearly based on the practice which is presumed to obtain in the case of ships-of-war, and which is, to some extent, necessary owing to the fact that the ocean being the common highway of all maritime nations, some declaration of nationality is obligatory, or at least desirable, from the point of view of neutrals as well as of belligerents. History has shown again and again that when a state of war exists, no rules, codified or otherwise, will compel a war-vessel or fleet to display its national flag, or prevent it from using the flag of any other nation that may commend itself at the moment; and if it were not for the interest of neutrals, the practice of employing any distinguishing flag or mark in war-time might fall into desuetude without affecting anything or anybody. Now, in the case of aircraft, it is not only improbable, but quite inconceivable, that civilians or neutrals will be permitted to fly at all in or near the zone ​of hostilities. It is even probable that on the declaration of war all private aircraft will be requisitioned or impounded (as now done in the case of wireless telegraphic apparatus), and that neutrals will be advised that they will use the territorial air of the belligerent countries entirely at their own risk and peril; in fact, that they will be shot down if detected. We cannot for an instant admit a state of things such as would arise were neutral or private aircraft (with war correspondents and suchlike) allowed to fly in any area in which fighting might be in progress; there would be continual uncertainty as to the nationality of such alien aircraft, and no means of checking the abuse of a neutral flag by spies or imposters. The position is totally different from that which obtains at sea. There is no possible means of investigation, and no time to ask questions; if there is any doubt, instant action is imperative. It is only too evident that even if distinguishing marks were agreed, no reliance would be placed upon their genuineness in real warfare, and their disuse, sooner or later, may be considered to be a foregone conclusion.
It will be part of the business of the airmen and gunners of both belligerent armies to be fully conversant with the peculiarities of the various types of aircraft in their own service and in that of the enemy, and to be sufficiently "fly" to detect any attempts at disguise or deception. It is, of course, always open to the aircraft of either army to carry a distinguishing mark or sign which can be displayed at will, and the nature of this may either be known or unknown to the enemy; it may, to ensure secrecy, be changed from time to time like a "pass-word." This, however, is an entirely different matter to the compulsory wearing of a badge, like a uniform or a national flag, by which the nationality will be openly declared as a matter of obligation.
​§ 105. Aircraft landing in Neutral Territory. Other questions of an international character relating to aircraft do not appear to present any serious difficulty. Evidently a belligerent aircraft descending into neutral territory will be interned, just as would a cavalryman or an armoured motor-car. To treat an aeroplane or airship according to the rule established in the case of a warship would clearly be to admit its right to have been in the territorial air of the neutral Power concerned, which, we may assume, will be considered quite inadmissible. Already, in the course of the present war, we have seen the hospitality of neutrals greatly abused. It certainly is not just or expedient that the cruisers of a nation which has ceased to possess any coaling stations, or bases, of its own should be allowed to roam indefinitely at large, interfering with the commerce of an enemy, when such action would have been impossible without neutral assistance. The proof of the inexpediency of the existing rule in such a case is to be found in the fact that the difficulty could be soon ended by a few declarations of war against some of the minor neutral Powers, with the bombardment of the ports by which the enemy is served. The very fact that this becomes the logical reply, which, but for humanitarian considerations, would without doubt be pursued, demonstrates an inherent deficiency in the present international code, and one which perhaps may, in due course, be remedied. Any rule by which aircraft would be enabled to utilise neutral territory or neutral resources for repair, refit, or replenishment would almost certainly be the cause of great friction, and might result in a position so impossible as to drag the neutral Power into the conflict, the precise eventuality that it should be an object of international convention to avoid.
In other respects there would seem to be no reason ​to treat the flying-machine or dirigible differently from arms or armament of other kinds, or belligerent airmen differently from other combatants. It is at least clear that any modifications in the accepted code which may eventually be found necessary may well be left to come as the natural outgrowth from experience in warfare. With regard to the manufacture and supply of aircraft by neutrals to belligerents, or the granting of facilities of transport, the same considerations will govern the decision of the neutral Power as are at present involved where arms and munitions of other kinds are concerned. The Power affected requires to consider in what way its own interests and those of neutrality are best served.
* ↑ It is, in fact, one of the main benefits of an international code that the friction between neutrals and belligerents should be minimised.
* ↑ If this view be accepted, the recent action of the British naval airmen in passing over Swiss territory is quite permissible and in no way irregular. Switzerland, had she so willed, could have employed aircraft to police her frontiers, in order to prevent the "borrowing" of her territorial air. Failing this, and not having suffered actual, i.e., material, injury, she has no ground of complaint.
* ↑ It would often appear from the framing of clauses and debates in connection with the various international conferences that the above (in the author's opinion the most important object of achievement of international conventions) is almost lost sight of in a quagmire of dangerous and namby-pamby sentimentality. In many cases the desire seems to be vaguely to do something that will be thought humane; no clear idea seems to exist as to right and proper grounds on which regulations of restrictions should be based. Thus, for example, in the Brussels Conference of 1874, Article 13 e, and in the Hague Conference of 1899, Article 23 e (already cited, Chapter VII.), the same restriction appears for the prohibition of bullets of the dum-dum or expanding type; in the first (the abortive Conference of 1874) the prohibition is worded:—"The use of arms, projectiles, or material of a nature to cause unnecessary suffering; the wording adopted at the later conference is "…of a nature to cause superfluous injury." At the 1874 Conference the assembly was, it appears, imbued with feelings of horror for pain and suffering, but in 1899 this seems to have become changed for a dread of disablement and death—a totally different matter. The suggested prohibition of bombs or missiles from aircraft is an illustration of the same infirmity of purpose that appears to reign supreme at peace conferences and the like; again we see the dictates of fear mistaken for those of benevolence. There is, and was, no evidence that bombs from aeroplanes or balloons are any more barbarous or inhumanly destructive than the shells from artillery or howitzer batteries, yet clauses were debated and framed, and (with a time-limit restriction) were actually signed by certain of the representatives of the Powers. The fear of the unknown is without doubt more widespread and potent than its victims realise. A cavalryman is killed in peace time by a fall from his horse, it scarcely excites comment; an army airman falls and is killed and a thrill of horror goes through the country—it is a new kind of death.