The New No-Man's-Land.—The recent war witnessed a rather sudden adoption of trench warfare, during a period in which the artillery strengths of both sides were relatively feeble, when compared with the later stages of the war. Accordingly, there arose very definite lines of field fortifications, and strongly held trench systems, separated from each other by a comparatively narrow No-Man's-Land, With the development of the formidable artillery strengths of belligerents, there was a tendency to form a much wider No-Man's-Land, and the front line systems were lightly held, approximating, in many cases, to an outpost line.
The discovery and mass production of a persistent lethal substance is likely to convert No-Man's-Land into a permanently infected gas zone, manned by special outposts of permanently protected troops. Combined with the development of smoke, this may render unnecessary the highly organised trench assembly systems of the recent war, used before the assault, and, with the development of the tank as a fast fighting machine, and for the transport of troops, one can obtain a glimpse of the nature of the new attack and counter-attack. A recent writer[1] has shown us the future tank carrying war into the enemy's country and destroying his nerve centres by actually reaching and paralysing the G.H.Q.s. of armies and smaller formations. Such operations will have to occur through a wide zone of the new gas and will necessitate the anti-gas tank. Indeed, one of the most important functions of the tank will be to carry the advance guard of an army beyond the infected No-Man's-Land, and such an advance will occur behind a series of smoke barrages created, in the first place, by the artillery, and, later, by the advance of tanks themselves.
[1] Tanks in the Great War, Col. J. F. C. Fuller., D.S.O.
The "Alert Gas Zone."—The development of the "gas alert" idea has definite interest for the future of chemical warfare. It is well known how the development of gas shell and surprise gas shoots by the Germans led to the necessity for "gas alert" conditions between certain times and within certain distances of the front line. The mask had to be worn in the so-called ready position, in order that swift adjustment might be possible in case of surprise attack. The summer of 1917 witnessed a great increase in gas shell activity. This was reflected in important changes in the "gas alert" regulations. In the autumn of that year all periods of readiness were abolished and replaced by a constant state of readiness. In the forward area absolute readiness was required within two miles of the front line, and special precautions were taken as far back as twelve miles. That the Germans suffered under the same restraints is witnessed by many captured documents. In particular, a divisional order taken in December, 1917, gave the gas danger zone as within fifteen kilometres of the front line, and within this region every one must carry a mask. The alert position of the mask was insisted upon within two kilometres of the front line. By July the alert zone had increased in depth in both armies. This tendency must have increased, had the war continued, for both sides were employing gas in guns of larger calibres, and weapons were being devised, such as the improved German Livens projector, which gave high concentrations at much greater distances from the front line, i.e. with greater critical ranges.
We have seen how the possible development of a persistent lethal compound may produce an infected and wide No-Man's-Land. Imposed on this, there will, no doubt, be "gas alert" conditions of great depths. How do these conceptions work out for the war of movement? It would appear that the possession of such a compound and the means of producing and using it on a very large scale could determine the stationary or open nature of warfare, if other forces were not too unequal. A new military factor emerges, the artificial, permanent, unmanned obstacle, which can be laid down at will on areas whose magnitude depends finally on manufacturing capacity. The germ of the idea appeared during the war at Kemmel and in the various mustard gas barrages formed by artillery or delayed mines used by the Germans in their great retreat. The sudden development of such barriers will be equivalent in effect to the creation of strong trench systems, but these could never result, under war conditions, in time to approach the strategic flexibility and importance of the persistent lethal infected barrier.
Gas and Aircraft.—The combination of gas and aircraft presents the possibility of attaining strategic effects by chemical means. Many rumours were afloat, towards the end of the war, regarding the use of gas by enemy aircraft, and there was apprehension amongst the civil populations, which has been reflected in numerous public utterances. Evidence on the matter is very scanty. In July, 1917, the use of gas in aeroplane bombs by the Germans was reported, but not confirmed. Further reports in August indicated the use of Blue Cross, owing to the sneezing effects which were produced on those within reach of the air bomb. In October, the evidence was more conclusive. But the German aeroplanes left no blind or dud shell, and, beyond the violent nasal and sneezing effects of Blue Cross, evidence was again absent. This report was very persistent, for, in July, 1918, there were again rumours that Blue Cross bombs had been dropped on the British near Ficheux. The Air Forces of the different armies were, perhaps, the last to feel the effects of the gas campaign, but the pilots of low-flying aeroplanes in the 1918 offensive were constantly crossing pockets of gas, and this, added to the fact that the pilots were often compelled to land in gas, led to their equipment with gas masks. A respirator of special type was taken from a German aviator in April, 1918, after the fighting at Passchendaele. But the war gave us no direct evidence of the successful use of gas and war chemicals from aircraft. This, however, is no criterion as to its eventual importance. The Allies definitely refrained from employing the combination until Germany should give them the start in what was regarded as a new atrocity. The main reason for their lack of development on these lines was probably the fact that the most suitable type of gas only developed during the later stages of the war, when it was required exceedingly urgently on the front. No really harmful persistent compound appeared before the advent of mustard gas, and the dangerous non-persistent types, such as phosgene, could not have been used with great success, owing to the fact that very considerable quantities would have been required to produce any serious effect. Mustard gas, however, which could have haunted a city for days, would not have been required in such large quantities. But its more urgent need on the front, and the fact that soon after it arrived the Germans were sending out feelers to see whether the Allies would consider the cessation of chemical warfare, were probably sufficient reasons to explain their failure to use it from aeroplanes.
Another point must be raised in connection with the use of gas from aircraft which has not yet received much attention. We must remember that the use of projectiles from aircraft over a city was a very different proposition from their use over a battle-field. One of the advantages of gas over explosives on the field of battle was its greater range of action. It produced effects at longer distances from the point of impact, but no such incentive existed for the use of gas from aeroplanes over large cities. Explosives, which might miss their objective on the field of battle, could not do so in a city. They were bound to hit something. The load of the aeroplane is always important, and the essential is to carry, weight for weight, the material which will produce the most effect. There is no doubt what this will he when the persistent lethal compound arrives, and mustard gas would probably have been superior to explosives for use by German aircraft on British cities.
Protective Development;—Individual Protection.—The question of protection against chemical attack presents some knotty problems for the future. Let us glance at the broad lines of war development in this field and forecast their future in a speculative way. Protection developed along two main lines. Individual protection covered the mask and any other protective appliance used by the individual soldier, while the term collective protection was applied to any method or appliance which afforded simultaneous protection for a number of individuals.
In general, the former represented an attempt to purify the poisoned air actually inspired by the soldier, whereas the latter was an attempt to purify the atmosphere of a locality or to prevent its initial poisoning. How far can the individual form of protection develop to meet the possibilities of the chemical attack? It certainly seems to have countered satisfactorily all the war attacks upon the respiratory system, although, as we have pointed out, the Germans might have failed, had we been sufficiently prompt in introducing our arsenic compounds. But we have forecasted the use of chemicals which may attack human functions hitherto immune. For the sake of our argument, we can divide these into two classes, those attained through the respiratory and digestive systems and those attained through contact with some other part of the body. The former can probably be satisfactorily met by developments in the mask. Even that does not appear certain, when we remember the emphasis laid by Germany upon the possibility of penetrating the mask by using a particulate cloud. The last word has certainly not been spoken in the struggle between the mask and the chemical attempting to penetrate it. But both the introduction of mustard gas and general speculative grounds justify us in concluding that attacks may materialise upon other parts of the human organism, We cannot foresee the actual point of attack and can, therefore, only view with assurance some form of protection which covers the whole body.
Collective Protection.—All parties dabbled in such a form of protection, but the French were the only ones to make a large-scale experiment on the front. It was not very successful, for the burden of these oilskin suits was intolerable. It may be that some successful form of protection for the whole body will materialise, but on general grounds we can assume that development will follow other lines. What are the possibilities? They all lie in the direction of collective protection. The individual cannot be satisfactorily protected from the new gas and remain an efficient soldier. We must, therefore, see whether it is not possible to protect numbers of men by removing them from contact with the poisoned atmosphere. A stationary form of such protection was used by all the armies, but emphasised by the French, by the creation of a large number of enormous underground chambers, some capable of holding more than a thousand men, the entries to which were carefully protected by special filtering devices to prevent the entry of the poisoned external atmosphere. On the British front these enormous dug-outs, although not absent, were largely replaced by the efficient gas-proof organisation of the smaller dugouts. The use of impregnated blankets for this purpose must be well known to any who visited the front or took part in hostilities. But you cannot imprison a whole army in this way. The value of these collective protective chambers depended on the fact that a certain number of men were always on the alert in the defensive systems outside and around the chambers, exposed to those gases against which the latter chambers were devised.