every cavalry commander tries to strike at the flank of his enemy, and the latter manœuvres to meet him, and if both have equal mobility, local collision must ensue on an equal and parallel front. Therefore both strive to put every available man and horse in their first line, and if men and horses were invulnerable such a line would sweep over the ground like a scythe and nothing could withstand it. Since, however, bullets kill at a distance, and inequalities and unforeseen difficulties of the ground may throw hundreds of horses and riders, a working compromise has to be found to meet eventualities, and, other things being equal, victory inclines to the leader who best measures the risks and uncertainties of his undertaking, and keeps in hand a sufficient reserve to meet all chances.
Thus there has arisen a saying, which is sometimes regarded as axiomatic, that in cavalry encounters the last closed reserve always wins. The truth is really that he who has best judged the situation and the men on both sides finds himself in possession of the last reserve at the critical moment. The next point is, how to ensure the presence of this reserve, and what is the critical moment. The battle-field is the critical moment in each phase of every campaign—not the mere chance locality on which a combat takes place, but the decisive arena on which the strategic consequences of all pre-existing conditions of national cohesion, national organization and of civilization are focussed. It is indeed the judgment-seat of nature, on which the right of the race to survive in the struggle for existence is weighed and measured in the most impartial scales.
Before, however, the final decision of the battle-field can be attained, a whole series of subordinate decisions have to be fought out, success in each of which conditions the result of the next series of encounters. Every commanding officer of cavalry thus finds himself successively called on to win a victory locally at any cost, and the question of economy of force does not concern him at all. Hence the same fundamental rules apply to all cavalry combats, of whatever magnitude, and condition the whole of cavalry tactics. Broadly speaking, if two cavalries of approximately equal mobility manœuvre against each other in open country, neither side can afford the loss of time that dismounting to fight on foot entails. Hence, assuming that at the outset of a campaign each side aims at securing a decisive success, both seek out an open plain and a mounted charge, sword in hand, for the decision. When the speed and skill of the combatants are approximately equal, collision ensues simultaneously along parallel fronts, and the threat of the overlapping line is the principal factor in the decision. The better the individual training of man and horse the less will be the chances of unsteadiness or local failures in execution, and the less the need of reserves; hence the force which feels itself the most perfect in the individual efficiency of both man and horse (on which therefore the whole ultimately depends) can afford to keep fewer men in reserve and can thus increase the width of its first line for the direct collision. Careful preparation in peace is therefore the first guarantee of success in action. This means that cavalry, unlike infantry, cannot be expanded by the absorption of reserve men and horses on the outbreak of hostilities, but must be maintained at war strength in peace, ready to take the field at a moment’s notice, and this is actually the standard of readiness attained on the continent of Europe at the present day.
Further, uniformity of speed is the essential condition for the execution of closed charges, and this obviously cannot be assured if big men on little horses and small men on big horses are indiscriminately mixed up in the same units. Horses and men have therefore been sorted out everywhere into three categories, light, medium and heavy, and in periods when war was practically chronic, suitable duties have been allotted to each. It is clear, on purely mechanical grounds, that the greater the velocity of motion at the moment of collision the greater will be the chances of success, and this greater speed will be on the side of the bigger horses as a consequence of their longer stride. On the other hand, these horses, by reason of their greater weight, are used up much more rapidly than small ones. Hence, to ensure the greater speed at the moment of contact, it is necessary to save them as much as possible to keep them fresh for the shock only, and this has been the practice of all great cavalry leaders all over the world, and has only been departed from under special circumstances, as by the Germans in France in 1870, when their cavalry practically rode everywhere unopposed.
Collisions, however, must be expected by every body of troops large or small; hence each regiment—ultimately each squadron—endeavours to save its horses as far as this is compatible with the attainment of the special object in view, and this has led everywhere and always to a demand for some intermediate arm, less expensive to raise and maintain than cavalry proper, and able to cover the ground with sufficient rapidity and collect the information necessary to ensure the proper direction of the cavalry commands. Originally this intermediate force received the designation of dragoons; but since under pressure of circumstances during long periods of war these invariably improved themselves into cavalry and became permanent units in the army organization, fresh names have had to be invented for them, of which Mounted Infantry and Mounted Rifles are the latest, and every improvement in firearms has led to an increased demand for their services.
It is now relatively easy to trace out the considerations which should govern the employment of his cavalry by the officer commanding a force of the three arms. Assuming for purposes of illustration an army numerically weak in cavalry, what course will best ensure the presence of the greatest number of sabres at the decisive point, i.e. on the battle-field? To push out cavalry screens far to the front will be to court destruction, nor is the information they obtain of much real service unless the means to act upon it at once is at hand. This can only be supplied economically by the use of strong advanced guards of infantry, and such supplementary security and information as these may require will be best supplied by mounted infantry, the sacrifice of whom will disturb least the fighting integrity of the whole army.
Imagine an army of 300,000 men advancing by five parallel roads on a front of 50 m., each column (60,000 men, 2 army corps) being covered by a strong advance guard, coming in contact with a similarly constituted army moving in an opposite direction. A series of engagements will ensue, in each of which the object of the local commander will be to paralyse his opponent’s will-power by a most vigorous attack, so that his superior officer following him on the same road will be free to act as he chooses. The front of the two armies will now be defined by a line of combats localized each about a comparatively small area, and between them will be wide gaps which it will be the chief business of the directing minds on either side to close by other troops as soon as possible. Generally the call will be made upon the artillery for this purpose, since they can cover the required distances far more rapidly than infantry. Now, as artillery is powerless when limbered up and always very vulnerable on the flanks of the long lines, a strong cavalry escort will have to be assigned to them which, trotting forward to screen the march, will either come in contact with the enemy’s cavalry advancing with a similar object, or themselves find an opportunity to catch the enemy’s guns at a disadvantage. These are opportunities for the cavalry, and if necessary it must sacrifice itself to turn them to the best account. The whole course of the battle depends on success or failure in the early formation of great lines of guns, for ultimately the victor in the artillery duel finds himself in command of the necessary balance of guns which are needed to prepare the way for his final decisive infantry attack. If this latter succeeds, then any mounted men who can gallop and shoot will suffice for pursuit. If it fails, no cavalry, however gallant, has any hope of definitely restoring the combat, for against victorious infantry, cavalry, now as in the past, can but gain a little time. This time may indeed be worth the price at which it can be bought, but it will always be more economical to concentrate all efforts to prevent the emergency arising.
After the Franco-German War much was written about the possibility of vast cavalry encounters to be fought far in advance of the main armies, for the purpose of obtaining information, and ideas were freely mooted of wide-flung raids traversing