On War

by Carl von Clausewitz

First, a national war, kept up by militia and a general levy (Landsturm), must naturally bring into the field a very numerous infantry; for in such wars there is a greater want of the means of equipment than of men, and as the equipment consequently is confined to what is indisputably necessary, we may easily imagine, that for every battery of eight pieces, not only one, but two or three battalions might be raised.

Second, if a weak state opposed to a powerful one cannot take refuge in a general call of the male population to regular military service, or in a militia system resembling it, then the increase of its artillery is certainly the shortest way of bringing up its weak army nearer to an equality with that of the enemy, for it saves men, and intensifies the essential principle of military force, that is, the destructive principle. Any way, such a state will mostly be confined to a limited theatre, and therefore this arm will be better suited to it. Frederick the Great adopted this means in the later period of the Seven Years’ War.

Third, cavalry is the arm for movement and great decisions; its increase beyond the ordinary proportions is therefore important if the war extends over a great space, if expeditions are to be made in various directions, and great and decisive blows are intended. Buonaparte is an example of this.

That the offensive and defensive do not properly in themselves exercise an influence on the proportion of cavalry will only appear plainly when we come to speak of these two methods of acting in war; in the meantime, we shall only remark that both assailant and defender as a rule traverse the same spaces in war, and may have also, at least in many cases, the same decisive intentions. We remind our readers of the campaign of 1812.

It is commonly believed that, in the middle ages, cavalry was much more numerous in proportion to infantry, and that the difference has been gradually on the decrease ever since. Yet this is a mistake, at least partly. The proportion of cavalry was, according to numbers, on the average perhaps, not much greater; of this we may convince ourselves by tracing, through the history of the middle ages, the detailed statements of the armed forces then employed. Let us only think of the masses of men on foot who composed the armies of the Crusaders, or the masses who followed the Emperors of Germany on their Roman expeditions. It was in reality the importance of the cavalry which was so much greater in those days; it was the stronger arm, composed of the flower of the people, so much so that, although always very much weaker actually in numbers, it was still always looked upon as the chief thing, infantry was little valued, hardly spoken of; hence has arisen the belief that its numbers were few. No doubt it happened oftener than it does now, that in incursions of small importance in France, Germany, and Italy, a small army was composed entirely of cavalry; as it was the chief arm, there is nothing inconsistent in that; but these cases decide nothing if we take a general view, as they are greatly outnumbered by cases of greater armies of the period constituted differently. It was only when the obligations to military service imposed by the feudal laws had ceased, and wars were carried on by soldiers enlisted, hired, and paid—when, therefore, wars depended on money and enlistment, that is, at the time of the Thirty Years’ War, and the wars of Louis XIV.—that this employment of great masses of almost useless infantry was checked, and perhaps in those days they might have fallen into the exclusive use of cavalry, if infantry had not just then risen in importance through the improvements in fire-arms, by which means it maintained its numerical superiority in proportion to cavalry; at this period, if infantry was weak, the proportion was as one to one, if numerous as three to one.

Since then cavalry has always decreased in importance according as improvements in the use of fire-arms have advanced. This is intelligible enough in itself, but the improvement we speak of does not relate solely to the weapon itself and the skill in handling it; we advert also to greater ability in using troops armed with this weapon. At the battle of Mollwitz the Prussian army had brought the fire of their infantry to such a state of perfection, that there has been no improvement since then in that sense. On the other hand, the use of infantry in broken ground and as skirmishers has been introduced more recently, and is to be looked upon as a very great advance in the art of destruction.

Our opinion is, therefore, that the relation of cavalry has not much changed as far as regards numbers, but as regards its importance, there has been a great alteration. This seems to be a contradiction, but is not so in reality. The infantry of the middle ages, although forming the greater proportion of an army, did not attain to that proportion by its value as compared to cavalry, but because all that could not be appointed to the very costly cavalry were handed over to the infantry; this infantry was, therefore, merely a last resource; and if the number of cavalry had depended merely on the value set on that arm, it could never have been too great. Thus we can understand how cavalry, in spite of its constantly decreasing importance, may still, perhaps, have importance enough to keep its numerical relation at that point which it has hitherto so constantly maintained.

It is a remarkable fact that, at least since the wars of the Austrian succession, the proportion of cavalry to infantry has changed very little, the variation being constantly between a fourth, a fifth or a sixth; this seems to indicate that those proportions meet the natural requirements of an army, and that these numbers give the solution which it is impossible to find in a direct manner. We doubt, however, if this is the case, and we find the principal instances of the employment of a numerous cavalry sufficiently accounted for by other causes.

Austria and Russia are states which have kept up a numerous cavalry, because they retain in their political condition the fragments of a Tartar organisation. Buonaparte for his purposes could never be strong enough in cavalry; when he had made use of the conscription as far as possible, he had no ways of strengthening his armies, but by increasing the auxiliary arms, as they cost him more in money than in men. Besides this, it stands to reason that in military enterprises of such enormous extent as his, cavalry must have a greater value than in ordinary cases.

Frederick the Great it is well known reckoned carefully every recruit that could be saved to his country; it was his great business to keep up the strength of his army, as far as possible at the expense of other countries. His reasons for this are easy to conceive, if we remember that his small dominions did not then include Prussia and the Westphalian provinces. Cavalry was kept complete by recruitment more easily than infantry, irrespective of fewer men being required; in addition to which, his system of war was completely founded on the mobility of his army, and thus it was, that while his infantry diminished in number, his cavalry was always increasing itself till the end of the Seven Years’ War. Still at the end of that war it was hardly more than a fourth of the number of infantry that he had in the field.