Some will probably feel inclined to ask what Clausewitz, who wrote more than eighty years ago, can possibly have to say about tactics which can be valuable in the twentieth century.

It was said by Napoleon that tactics change every ten years, according, of course, to the progress of technicalities, etc. Weapons indeed change, but there is one thing that never changes, and that is human nature. The most important thing in tactics, the man behind the gun, never alters; in his heart and feelings, his strength and weakness, he is always much the same. Therefore, Clausewitz's tactical deductions, founded on the immense and varied data supplied by the desperate and long-continued fighting of the Revolutionary and Napoleonic wars, permeated as they are by his all-pervading psychological or moral view, can never lose their value to us.

It is true, no doubt, that our rifles of to-day can be used with effect at a distance ten times as great as the old smooth bores of Clausewitz's day, our shrapnel five times as far as his cannon, and that cover and ground play a far more important part now than then, and so on. All these things, of course, considerably modify the tactics of Clausewitz. Not so much, however, as some text-books would lead us to suppose, which always seem to assume clear ground and clear weather. For, after all, how many combats are fought on ground where there is a very restricted field of fire (vide Herbert's "Defence of Plevna," etc.), or at night? How many battles are fought during rain, or snow, or mist, or fog, which destroys all long range? Compare the tremendous fighting with "bullets, bayonets, swords, hand-grenades, and even fists," of Nogi's attempt to cut the Russian line of retreat at Mukden, with the hand-to-hand fighting of Eylau, Friedland, Borodino, or with the desperate efforts of the French in 1812 to open their line of retreat through Maro-Jaroslawitz, where all day the masses of troops fought hand-to-hand in the streets, "the town was taken and retaken seven times, and the rival nations fought with the bayonet in the midst of the burning houses" (Alison).

When it comes to push of pike, as in all great decisions between equally resolute adversaries it is bound to do, the difference between the fighting of Clausewitz's day and ours is but small. The most recent instances of all, the hand-to-hand fighting in Manchuria, take us back to the Napoleonic struggles.

Therefore, despite the eighty years that have intervened, the writings of Clausewitz are still valuable from a tactical point of view, always considering of course the difference in weapons, because of the human heart in battle.

His ideas on tactics have largely filtered through his German pupils into our textbooks, minus the psychological or moral note, so that it is not necessary to go at length into the subject, or give a number of extracts. It would be wearisome. I will, however, give a few passages at haphazard as illustrations.

Flank Attacks

The endeavour to gain the enemy's line of retreat, and protect our own, on which so much learned erudition has been spent by various writers, he regards as a NATURAL instinct, which will ALWAYS produce itself both in generals and subalterns.

"From this arises, in the whole conduct of war, and especially in great and small combats, a PERFECT INSTINCT, which is the security of our own line of retreat and the seizure of the enemy's; this follows from the conception of victory, which, as we have seen, is something beyond mere slaughter. In this effort we see, therefore, the FIRST immediate purpose in the combat, and one which is quite universal. No combat is imaginable in which this effort, either in its double or single form, is not to go hand in hand with the plain and simple stroke of force. Even the smallest troop will not throw itself upon the enemy without thinking of its line of retreat, and in most cases it will have an eye upon that of the enemy."62 "This is a great natural law of the combat," "and so becomes the pivot upon which ALL strategical and tactical manoeuvres turn."

Reserves?—?Destructive and Decisive Act

The combat he regards as settled by whoever has the preponderance of moral force at the end; that is, in fresh or only partly used up troops.

The combat itself he divides into a destructive and a decisive act. During the long destructive act, or period of fire preparation, the troops engaged gradually wear each other out, and gradually almost cease to count as factors in the decision. "After a fire combat of some hours' duration, in which a body of troops has suffered severe losses?—?for instance, a quarter or one-third of its numbers?—?the dÉbris may for the time be looked upon as a heap of cinders. For the men are physically exhausted; they have spent their ammunition; many have left the field with the wounded, though not themselves wounded (compare, for instance, Eylau and the 1870 battles); the rest think they have done their part for the day, and if they get beyond the sphere of danger, do not willingly return to it. The feeling of courage with which they originally started has had the edge taken off, the longing for the fight is satisfied, the original organization is partly destroyed, and the formations broken up."

"So that the amount of moral force lost may be estimated by the amount of the Reserves used up, almost as with a foot rule."63

This goes on till, "In all probability, only the untouched reserve and some troops which, though they have been in action, have suffered very little, are in reality to be regarded as serviceable, and the remainder (perhaps four-sixths) may be looked upon for the present as a "caput mortuum."

Therefore the art of the commander he regards as "economy of force" during the destructive period; that is, to employ as few troops as possible, by taking advantage of ground, cover, etc., "to use a smaller number of men in the combat with firearms than the enemy employs," so that a smaller proportionate number of his own are reduced to a "heap of cinders" and more are left, more moral force, for the decision. "Hundreds of times," he says, "a line of fire has maintained its own against one twice its strength" (e.g. the Boers).

To do this and yet obtain a good fire-effect demands very skilful handling of the troops, both on the part of the chief and subordinate leaders.

With the preponderance thus obtained the commander at last starts the decision. "Towards the close of a battle the line of retreat is always regarded with increased jealousy, therefore a threat against that line is always a potent means of bringing on the decision (Liao-yang, Mukden). On that account, when circumstances permit, the plan of battle will be aimed at that point from the very first." Or, "If this wear and tear and exhaustion of the forces has reached a certain pitch, then a rapid advance in concentrated masses on one side against the line of battle of the other" (i.e. the Napoleonic breaking the centre, of recent years thought almost hopeless, but revived in Manchuria with success, in the case of Nodzu breaking the centre at Mukden).

From what precedes it is evident that, as in the preparatory acts, the utmost economy of forces must prevail, so in the decisive act to win the mastery through numbers must be the ruling idea.

Just as in the preparatory acts endurance, firmness and coolness are the first qualities, so in the decisive act boldness and fiery spirit must predominate.

"The difference between these two acts will never be completely lost as respects the whole."

"This is the way in which our view is to be understood; then, on the one hand, it will not come short of the reality, and on the other it will direct the attention of the leader of a combat (be it great or small, partial or general) to giving each of the two acts of activity its due share, so that there may be neither precipitation nor negligence.

"Precipitation there will be if space and time are not allowed for the destructive act. Negligence in general there will be if a complete decision does not take place, either from want of moral courage or from a wrong view of the situation."64

Duration of the Combat

"Even the resistance of an ordinary division of 8,000 or 10,000 men of all arms, even if opposed to an enemy considerably superior in numbers, will last several hours, if the advantages of country are not too preponderating. And if the enemy is only a little or not at all superior in numbers, the combat will last half a day. A corps of three or four divisions will prolong it to double that time; an army of 80,000 or 100,000 men to three or four times." "These calculations are the result of experience."65

As General von Caemmerer points out, if these calculations were adhered to in present-day German manoeuvres, as they are now in all war games, tactical exercises, and staff rides, the dangerous dualism of their training, the difference between theory and manoeuvre practice, would cease.

Attack and Defence

I have left to the last the consideration of three or four disputed points in Clausewitz. In considering these I shall quote a good deal from General von Caemmerer's "Development of Strategical Science," as in such matters it is best to quote the most recent authors of established reputation.

The most important of these, and the most disputed, is Clausewitz's famous dictum that "the defensive is the stronger form of making war." "The defence is the stronger form of war with a negative object; the attack is the weaker form with a positive object."66

General von Caemmerer says, "It is strange, we Germans look upon Clausewitz as indisputably the deepest and acutest thinker upon the subject of war; the beneficial effect of his intellectual labours is universally recognized and highly appreciated; but the more or less keen opposition against this sentence never ceases. And yet that sentence can as little be cut out of his work 'On War' as the heart out of a man. Our most distinguished and prominent military writers are here at variance with Clausewitz.

"Now, of course, I do not here propose to go into such a controversy. I only wish to point out that Clausewitz, in saying this, only meant the defensive-offensive, the form in which he always regards it, both strategically and technically, in oft-repeated explanations all through his works. For instance?—?

"It is a FIRST maxim NEVER to remain perfectly passive, but to fall upon the enemy in front and flank, even when he is in the act of making an attack upon us."67

And again?—?

"A swift and vigorous assumption of the offensive?—?the flashing sword of vengeance?—?is the most brilliant point in the defensive. He who does not at once think of it at the right moment, or rather he who does not from the first include this transition in his idea of the defensive, will never understand its superiority as a form of war."68 Von Caemmerer comments thus: "And this conception of the defence by Clausewitz has become part and parcel of our army?—?everywhere, strategically and tactically, he who has been forced into a defensive attitude at once thinks how he can arrange a counter-attack. I am thus unable to see how the way in which Clausewitz has contrasted Attack and Defence could in any way paralyse the spirit of enterprise." Von Caemmerer also justly remarks that, as Clausewitz always insisted both in strategy and tactics, neither Attack nor Defence is pure, but oscillates between the two forms; and as the Attack is frequently temporarily reduced to defend itself, and also as no nation can be sure of never being invaded by a superior coalition, it is most desirable to encourage a belief in the strength of the Defence, if properly used. In this I think that Wellington would probably have agreed. Certainly Austerlitz and Waterloo were examples of battles such as Clausewitz preferred.

Still, one must admit that Clausewitz's chapter on "The Relations of the Offensive and Defensive to each other in Tactics," Book VII. Chapter 2, is the least convincing chapter of his work.

Strategically, the argument is stronger. It always seems to me that we must remember that Clausewitz had taken part in the defensive-offensive in its strongest, most absolute and unlimited form, on the greatest possible scale?—?the Moscow campaign and the ruin (consummated before a single flake of snow fell) of the Grand Army. If he had lived to complete the revision of his works, it always seems to me that he would have made his theory undeniable by stating that the defensive is the strongest form of war, if unlimited by space. What, for instance, would have happened if the Japanese had tried to march through Siberia on to St. Petersburg?

But, after all, which of the two is absolutely the stronger form of war, attack or defence, is merely a theoretical abstraction, for, practically, the choice is always settled for us by the pressing necessity of circumstances. And, in this connection, let us always bear in mind Clausewitz's dictum: "A swift and vigorous assumption of the offensive?—?the flashing sword of vengeance?—?is the most brilliant point in the defensive."

The Inner Line

A second disputed point is Clausewitz's alleged preference, as a rule, for the Inner Line in strategy. But it is necessary to remember that that was only due to the conditions of his time, before railways and telegraphs, when it was difficult to communicate between columns acting on concentric lines. And he is not in any way wedded to the Inner Line, like Jomini, but only when circumstances are favourable. He has many sentences from which we may infer that, had he lived in railway and telegraph days, his strategy, like Moltke's, his most distinguished pupil, would have aimed at envelopment as a rule. For to bring up troops rapidly by several railways necessitates a broad strategic front, and Clausewitz especially lays down rapidity as his second great principle, and says?—?

"If the concentration of the forces would occasion detours and loss of time, and the danger of advancing by separate lines is not too great, then the same may be justifiable on these grounds; for to effect an unnecessary concentration of the forces would be contrary to the second principle we have laid down (i.e. 'to act as swiftly as possible')."69 Also: "Such separation into several columns as is absolutely necessary must be made use of for the disposition of the tactical attack in the enveloping form, for that form is natural to the attack, and must not be disregarded without good reason."70 Also: "It is sufficient now if the concentration takes place during the action." So that while the conditions of his time led Clausewitz to prefer close concentration and the Inner Line, like Napoleon, yet his reflections led him to propound the germ of the strategy of Moltke. Substitute for Clausewitz's close concentration this: "As close concentration, the combined movements regulated by telegraph, as is compatible with the utmost use of the railways and the greatest rapidity" (as he would certainly have said), and we arrive at Moltke's strategy.

Frontal Attacks

A third disputed point is his belief in the superior tactical efficiency, under favourable circumstances, of the Napoleonic method of breaking the enemy's line in the centre. Breaking the line by a frontal attack was, of course, much easier in Clausewitz's Napoleonic day than it is with the long-ranging arms of our day, and it is only natural that Clausewitz in his writings should give it the full tactical importance which it then deserved. His book would not be true to the tactical conditions of his day had he not done so, with Rivoli, Austerlitz, Salamanca, Eckmuhl, etc., before his mind. But it seems hardly correct to accuse him of over-partiality to frontal attacks, for he has examined both frontal and enveloping attacks most fairly, giving to each their relative advantages and disadvantages, and concluding: "The envelopment may lead directly to the destruction of the enemy's army, if it is made with very superior numbers and succeeds. If it leads to victory the early results are in every case greater than by breaking the enemy's line. Breaking the enemy's line can only lead indirectly to the destruction of the enemy's army, and its effects are hardly shown so much on the first day, but rather strategically afterwards,"71 by forcing apart on different lines of retreat the separated fragments of the beaten army.

"The breaking through the hostile army by massing our principal force against one point, supposes an excessive length of front on the part of the enemy; for in this form of attack the difficulty of occupying the remainder of the enemy's force with few troops is greater, because the enemy's forces nearer to the principal point of attack can easily join in opposing it. Now in an attack upon the centre there are such forces on both sides of the attack; in an attack upon a flank, only on one side. The consequence of this is that such a central attack may easily end in a very disadvantageous form of combat, through a convergent counter-attack." Which is exactly our modern difficulty. "The choice between these two forms of attack must therefore be made according to the existing conditions of the moment. Length of front, the nature and direction of the line of retreat, the military qualities of the enemy's troops, and the characteristics of their general, lastly the ground must determine the choice."

Speaking generally he regards the concentric enveloping form of tactical attack aiming at the enemy's line of retreat as the most efficacious and natural. "On the field of battle itself ... the enveloping form must always be considered the most effectual."72 And the eccentric or frontal counter-attack at the extended enveloping attack as the most efficacious and natural form of the defence, such as Napoleon's counter-attacks at Austerlitz or Dresden, or Wellington's at Salamanca. "And we think that one means is at least as good as the other."73

Now I think that these extracts sufficiently defend Clausewitz from the imputation of too great a belief in frontal attacks, and considering the frequent success of such Napoleonic attacks in his day, he gives a very fair summing up of the relative advantages and disadvantages thereof, and indeed such as might be written in the present day. Indeed the quite abnormal conditions of the Boer war produced such a feeling against frontal attacks, and so much loose talk of their being extinct, that it is very useful to turn to Clausewitz for a reminder that breaking the centre, whenever the condition he postulates, namely over-extension of front on the enemy's part, is present, will always remain one of the two great forms of decisive attack open to a commander.

And as in our day the forces are so enormous that to reach the hostile flank becomes more difficult, and the extension of front becomes so gigantic (a front of several armies on a line of forty to seventy miles perhaps), it is well to consider whether breaking the enemy's centre will not again offer the most advantageous form for the final decisive act, coupled of course, as Clausewitz says it ALWAYS MUST be, with a strong flank attack. And in these gigantic battles of the future, such as Liao-yang and Mukden, which we must consider typical of the future, battles which must take several days, during which the troops in the first line become utterly exhausted and used up,?—?a decisive attack on the centre can well be imagined after the hostile reserves have been decoyed away over a day's march by a strong flank attack. As, for example, Nogi's flank attack round Mukden followed by Nodzu's decisive breaking the centre and capture of Mukden itself.

So that far from thinking Clausewitz's remarks about frontal attacks and breaking the line to be obsolete, it rather appears from the great Russo-Japanese battles that they are worthy of close study in view of the future.

Tactical versus Strategical Envelopment

A fourth disputed point is the preference of Clausewitz, owing to his insistence on the greatest concentration possible with proper regard for the circumstances, for the tactical envelopment arranged on or near the field to strategical envelopment with divided forces arranged beforehand. In this matter I will again quote General v. Caemmerer, who disagrees with him, and says: "Clausewitz proclaims the oblique front as the most effective strategic form of attack, ... that is to say, when the whole army with one united front falls upon the strategic flank of the enemy, and, if victorious, cuts him from his line of retreat. But where such a situation cannot be brought about, where our advance has brought us before the strategic front of the enemy, then he sees in the tactical envelopment, in the formation of an offensive flank, the proper means of effectively preparing to push the enemy from his line of retreat, and he distinctly explains that tactical envelopment need not at all be the consequence of strategical envelopment, and need not at all be prepared long beforehand by a corresponding advance of divided forces."

Clausewitz says, "The consequence of this is that battles fought with enveloping lines, or even with an oblique front, which should properly result from an advantageous relation of the lines of communication, are commonly the result of a moral and physical preponderance."74 Also "he should therefore only advance with his columns on such a width of front as will admit of their all coming into action together." "Such separation into several columns should be made use of for the disposition of the tactical attack in the enveloping form" (i.e. by troops within a day's march of each other). "But it must be only of a tactical nature, for a strategic envelopment, when a great blow is to be struck, is a complete waste of power."

General v. Caemmerer comments: "He is thus of opinion that the lateral movement of part of the army against the flank of the enemy could without any difficulty still be carried out as initiated by the plan of battle; and in order to understand this idea we must again bear in mind the difference between the fire-effect of then and now. In those days a comparatively short movement made it still possible for a considerable portion of the army to gain the defenders' flank; to-day a lengthy and troublesome operation would be necessary for the same object, and its successful execution would only be counted upon if the defender remained entirely passive, and would neither think of a counter-stroke nor of a corresponding movement of his forces to the threatened flank."

Without going into this controversy I will, however, quote the excellent reason given by Clausewitz for his preference for tactical as opposed to strategical envelopment: "One peculiarity of the offensive battle is the uncertainty, in most cases, as to the position (note, and strength) of the enemy; it is a complete groping about amongst things that are unknown (Austerlitz, Wagram, Hohenlinden, Jena, Katzbach). The more this is the case the more concentration of forces becomes paramount, and turning a flank to be preferred to surrounding."75

It is also well to recollect how many famous generals had been ruined in Clausewitz's experience through over-extension or dispersion of their forces. The crushing defeats of Napoleon's marshals in the winter of 1813, Macdonald at the Katzbach, Oudinot at Gros Beeren, Ney at Dennewitz, which neutralized Napoleon's great victory at Dresden and began his ruin, were all chiefly owing to this cause.

And the weather may, again, have as great influence in shortening resistance and allowing troops to be overwhelmed before the too-distant reinforcements arrive, as it had in those battles. If the weather then prevented the old muskets going off, and enabled the attack to rush the defence, so now a fog, rain, mist, or snow, by restricting the field of view and fire, may produce the same results. When one thinks of the number of great battles fought in such weather, as they may well be again, one sees an additional reason for carefully considering Clausewitz's warning. Far from relegating his preference for the tactical as opposed to the strategical envelopment to the region of the obsolete, because of our improved armament, it seems right to give it full weight as a corrective to a perceivable tendency to elevate strategical envelopment (after KÖniggrÄtz) into a formula for victory. If in the past many great generals have been ruined by over-extension, so may they be again. Against this tendency Clausewitz will for ever lift his voice.

Also it remains to be considered, with the huge armies of to-day and the future, such armies as at Liao-yang and Mukden, such armies as may possibly one day join issue in Afghanistan, whether strategical envelopment will be practicable, or whether tactical envelopment, such as General Kuroki's tactical enveloping movement on Yentai, and the Russian line of retreat at Liao-yang, or General Nogi's tactical enveloping dash northward on Hsinminting and the railway at Mukden, will not be preferable.

Perhaps, as a compromise, one might call such a movement strategical-tactical, and so avoid the dispute by jugglery of words.

I have not attempted to do more than roughly indicate that the solution of these four disputed tactical questions in Clausewitz is to be sought in a study of the latest campaign, as he would have said himself; that is, the campaign in Manchuria. For, as the Times correspondent in the XLVth Chapter, "Clausewitz in Manchuria," of his book "The War in the Far East," observes, "It will be abundantly clear to any one who has followed the great battles in Manchuria that the spirit of Clausewitz has presided over Japanese victories and wept over Russian defeats."