If we make this idea the basis of our argument, the following is the result. Infantry has gained enormously in defensive power owing to modern weapons. The attack requires, therefore, a far greater superiority than ever before. In addition to this, the breadth of front in action has greatly increased in consequence of the former close tactical formations having been broken up through the increase of fire. This refers only to the separate detachment, and does not justify the conclusion that in the future fewer troops will cover the same spaces as before. This assumption applies at the most to defence, and then only in a limited sense. In attack the opposite will probably be the case. The troops must therefore be placed more deeply _en échelon _than in the last wars. Now, the average breadth of the front in attack must regulate the allotment of artillery to infantry. No definite proportion can be settled; but if the theoretical calculation be compared with the experiences of the last wars, conclusions may be obtained which will most probably prove appropriate. No more than this can be expected in the domain of military science.
If we agree to the above-mentioned proportion of breadth and depth in an infantry attack, we shall be driven to insist on a reduction of artillery as compared with the past; but should we think that modern artillery helps the attack, especially by indirect fire, we must advocate, from the standpoint of offensive warfare, an increase of the artillery. Actual war experiences alone can find the true middle path between these two extremes.
If the frontal development of the artillery of a modern army corps, or, better still, two divisions, be regarded from the point of view that the guns cannot advance in connected line, but that only the specially adapted parts of the field can be used for artillery development, the conclusion is certain that by such frontal extension the infantry is reduced to a covering line for the artillery. In forming this opinion we must not assume the normal strength of the infantry, but take into account that the strength of the infantry in war rapidly melts away. If we estimate the companies on the average at two-thirds of their proper strength, we shall be above rather than below the real figures. Such infantry strength will, of course, be sufficient to defend the position taken up by the artillery, but it is hardly enough to carry out, in that section of the field, a decisive attack, which, under present conditions, requires greater numbers and depth than before.
In this connection it is very instructive to study the second part of the Franco-German War, and the Boer War, as well as the Manchurian campaign.
Some of the German infantry had in the first-named period extraordinarily diminished in numbers; companies of 120 men were not rare. The artillery, on the contrary, had remained at its original strength. The consequences naturally was that the powers of the Germans on the offensive grew less and the battles and skirmishes were not so decisive as in the first part of the war. This condition would have shown up more distinctly against an enemy of equal class than in the contest with the loosely-compacted, raw French levies. In the former case the offensive would have been impracticable. The strong artillery, under the existing conditions, no doubt gave great support to the weak infantry; but an unbiassed opinion leads to the conclusion that, under the then existing proportion of the arms to each other, the infantry was too weak to adopt energetic offensive tactics against a well-matched enemy. This is irresistibly proved if we consider what masses of infantry were needed at Wörth and St. Privat, for instance, in spite of the support of very superior artillery, in order to defeat a weaker enemy of equal class.
Again, in South Africa, the overwhelming superiority of the English in artillery was never able to force a victory. In Manchuria the state of things was very instructive. Numerically the Russian artillery was extraordinarily superior to the enemy's, and the range of the Russian field guns was longer than that of the Japanese; nevertheless, the Japanese succeeded in beating an enemy stronger in infantry also, because, in the decisive directions of attack, they were able to unite superior forces of infantry and artillery, while the Russian artillery was scattered along the whole of their broad front.
The lesson of this war is that, apart from the close relation of the arms to each other in the separate units, the co-operation of these units must be looked at, if the strength of the two sister arms is to be appropriately determined.
The requirement that each separate tactical unit should he made equal or superior in artillery to the corresponding hostile unit is thoroughly mechanical, as if in war division always fought against division and corps against corps! Superiority at the decisive point is the crucial test. This superiority is attained by means of an unexpected concentration of forces for attack, and there is no reason why the superiority in artillery should not also be brought about in this way. If by superior tactical skill two army corps, each with 96 guns, combine against a hostile army which brings 144 guns into action, that signifies a superiority of 48 guns and a double superiority in infantry. If it is assumed that on both sides the army corps is armed with 144 guns, and that in consequence of this the tactical superiority has become so slight that neither side can claim a superiority in one direction, then equal forces meet, and chance decides the day. Since the Japanese were tactically more efficient than their enemy and took the offensive, they were enabled to unite the superior forces in the most decisive directions, and this advantage proved far greater than the numerical superiority of the Russian army as a whole.
If we look at the whole matter we shall come to the conclusion that the artillery, if it is not a question of pure defence, need never occupy within a line of battle so much ground that the concentration of a considerably superior force of infantry for attack is rendered doubtful. In this respect we have, in our present organization already exceeded the expedient proportion between the two arms in favour of the artillery. The conclusion is that this latter arm never need, within the separate divisions, be made so strong that the attacking capacities of the army are thereby prejudiced. This is the decisive point. Any excess in artillery can be kept on the battlefield in reserve when space is restricted; if the attacking efficiency of the troops is reduced, then artillery becomes a dead weight on the army instead of an aid to victory. It is far more important to be able to unite superior forces for a decisive attack than to meet the enemy with equally matched forces along the whole front. If we observe this principle, we shall often be weaker than the enemy on the less important fronts; this disadvantage may be partly counterbalanced by remaining on the defensive in such a position. It becomes a positive advantage, if, owing to an overpowering concentration of forces, victory is won at the decisive point. This victory cancels all the failures which may have been recorded elsewhere.
The operative superiority of an enemy is determined by the greater marching capacity of the troops, by the rapid and systematic working of the communications with the rear, and, above all, by the length of the columns of the operating troops. Under the modern system of colossal armaments, an army, especially if in close formation, cannot possibly live on the country; it is driven to trust to daily food-supplies from the rear. Railways are used as far as possible to bring up the supplies; but from the railhead the communication with the troops must be maintained by columns of traction waggons and draught animals, which go to and fro between the troops, the rearward magazines, and the railhead. Since traction waggons are restricted to made roads, the direct communication with the troops must be kept up by columns of draught animals, which can move independently of the roads. The waggons of provisions, therefore, which follow the troops, and are filled daily, must come up with them the same day, or there will be a shortage of food. This is only possible if the troop column does not exceed a certain length and starts at early morning, so that the transport waggons, which, at the end of the march, must be driven from the rear to the head of the column, can reach this before the beginning of the night's rest. The fitness of an army for attack can only be maintained if these supplies are uninterrupted; there must also be a sufficient quantity of tinned rations and provisions which the soldiers can carry with them. If the length of the columns exceeds the limit here laid down, the marches must be proportionately shortened. If unusually lengthy marches are made, so that the provision carts cannot reach the troops, days of rest must be interposed, to regulate the supply. Thus the capacity of an army to march and to carry out operations is directly dependent on the possibility of being fed from the rear. A careful calculation, based on practical experiences, shows that, in order to average 20 to 22 kilometres a day—the minimum distance required from an army—no column on a road ought to exceed a length of about 25 kilometres This consideration determines the depth of the army corps on the march, since in an important campaign and when massing for battle troops seldom march in smaller bodies than a corps.