CHAPTER IX - Defensive Battle
We have said, in the preceding chapter, that the defender, in his defensive, would make use of a battle, technically speaking, of a purely offensive character, if, at the moment the enemy invades his theatre of war, he marches against him and attacks him; but that he might also wait for the appearance of the enemy in his front, and then pass over to the attack; in which case also the battle tactically would be again an offensive battle, although in a modified form; and lastly, that he might wait till the enemy attacked his position, and then oppose him both by holding a particular spot, and by offensive action with portions of his force. In all this we may imagine several different gradations and shades, deviating always more from the principle of a positive counterstroke, and passing into that of the defence of a spot of ground. We cannot here enter on the subject of how far this should be carried, and which is the most advantageous proportion of the two elements of offensive and defensive, as regards the winning a decisive victory. But we maintain that when such a result is desired, the offensive part of the battle should never be completely omitted, and we are convinced that all the effects of a decisive victory may and must be produced by this offensive part, just as well as in a purely tactical offensive battle.
In the same manner as the field of battle is only a point in strategy, the duration of a battle is only, strategically, an instant of time, and the end and result, not the course of a battle, constitutes a strategic quantity.
Now, if it is true that a complete victory may result from the offensive elements which lie in every defensive battle, then there would be no fundamental difference between an offensive and a defensive battle, as far as regards strategic combinations; we are indeed convinced that this is so, but the thing wears a different appearance. In order to fix the subject more distinctly in the eye, to make our view clear and thereby remove the appearance now referred to, we shall sketch, hastily, the picture of a defensive battle, such as we imagine it.
The defensive waits the attack in a position; for this he has selected proper ground, and turned it to the best account, that is, he has made himself well acquainted with the locality, thrown up strong entrenchments at some of the most important points, opened and levelled communications, constructed batteries, fortified villages, and looked out places where he can draw up his masses under cover, etc., etc., etc. Whilst the forces on both sides are consuming each other at the different points where they come into contact, the advantage of a front more or less strong, the approach to which is made difficult by one or more parallel trenches or other obstacles, or also by the influence of some strong commanding points, enables him with a small part of his force to destroy great numbers of the enemy at every stage of the defence up to the heart of the position. The points of support which he has given his wings secure him from any sudden attack from several quarters; the covered ground which he has chosen for his masses makes the enemy cautious, indeed timid, and affords the defensive the means of diminishing by partial and successful attacks the general backward movement which goes on as the combat becomes gradually concentrated within narrower limits. The defender therefore casts a contented look at the battle as it burns in a moderate blaze before him;—but he does not reckon that his resistance in front can last for ever;—he does not think his flanks impregnable;—he does not expect that the whole course of the battle will be changed by the successful charge of a few battalions or squadrons. His position is deep, for each part in the scale of gradation of the order of battle, from the division down to the battalion, has its reserve for unforeseen events, and for a renewal of the fight; and at the same time an important mass, one fifth to a quarter of the whole, is kept quite in the rear out of the battle, so far back as to be quite out of fire, and if possible so far as to be beyond the circuitous line by which the enemy might attempt to turn either flank. With this corps he intends to cover his flanks from wider and greater turning movements, secure himself against unforeseen events, and in the latter stage of the battle, when the assailant’s plan is fully developed, when the most of his troops have been brought into action, he will throw this mass on a part of the enemy’s army, and open at that part of the field a smaller offensive battle on his own part, using all the elements of attack, such as charges, surprise, turning movements, and by means of this pressure against the centre of gravity of the battle, now only resting on a point, make the whole recoil.
This is the normal idea which we have formed of a defensive battle, based on the tactics of the present day. In this battle the general turning movement made by the assailant in order to assist his attack, and at the same time with a view to make the results of victory more complete, is replied to by a partial turning movement on the part of the defensive, that is, by the turning of that part of the assailant’s force used by him in the attempt to turn. This partial movement may be supposed sufficient to destroy the effect of the enemy’s attempt, but it cannot lead to a like general enveloping of the assailant’s army; and there will always be a distinction in the features of a victory on this account, that the side fighting an offensive battle encircles the enemy’s army, and acts towards the centre of the same, while the side fighting on the defensive acts more or less from the centre to the circumference, in the direction of the radii.
On the field of battle itself, and in the first stages of the pursuit, the enveloping form must always be considered the most effectual; we do not mean on account of its form generally, we only mean in the event of its being carried out to such an extreme as to limit very much the enemy’s means of retreat during the battle. But it is just against this extreme point that the enemy’s positive counter-effort is directed, and in many cases where this effort is not sufficient to obtain a victory, it will at least suffice to protect him from such an extreme as we allude to. But we must always admit that this danger, namely, of having the line of retreat seriously contracted, is particularly great in defensive battles, and if it cannot be guarded against, the results in the battle itself, and in the first stage of the retreat are thereby very much enhanced in favour of the enemy.
But as a rule this danger does not extend beyond the first stage of the retreat, that is, until night-fall; on the following day enveloping is at an end, and both parties are again on an equality in this respect.
Certainly the defender may have lost his principal line of retreat, and therefore be placed in a disadvantageous strategic situation for the future; but in most cases the turning movement itself will be at an end, because it was only planned to suit the field of battle, and therefore cannot apply much further. But what will take place, on the other hand, if the defender is victorious? A division of the defeated force. This may facilitate the retreat at the first moment, but next day a concentration of all parts is the one thing most needful. Now if the victory is a most decisive one, if the defender pursues with great energy, this concentration will often become impossible, and from this separation of the beaten force the worst consequences may follow, which may go on step by step to a complete rout. If Buonaparte had conquered at Leipsic, the allied army would have been completely cut in two, which would have considerably lowered their relative strategic position. At Dresden, although Buonaparte certainly did not fight a regular defensive battle, the attack had the geometrical form of which we have been speaking, that is, from the centre to the circumference; the embarrassment of the Allies in consequence of their separation, is well known, an embarrassment from which they were only relieved by the victory on the Katzbach, the tidings of which caused Buonaparte to return to Dresden with the Guard.
This battle on the Katzbach itself is a similar example. In it the defender, at the last moment passes over to the offensive, and consequently operates on diverging lines; the French corps were thus wedged asunder, and several days after, as the fruits of the victory, Puthod’s division fell into the hands of the Allies.
The conclusion we draw from this is, that if the assailant, by the concentric form which is homogeneous to him, has the means of giving expansion to his victory, on the other hand the defender also, by the divergent form which is homogeneous to the defence, acquires a a means of giving greater results to his victory than would be the case by a merely parallel position and perpendicular attack, and we think that one means is at least as good as the other.
If in military history we rarely find such great victories resulting from the defensive battle as from the offensive, that proves nothing against our assertion that the one is as well suited to produce victory as the other; the real cause is in the very different relations of the defender. The army acting on the defensive is generally the weaker of the two, not only in the amount of his forces, but also in every other respect; he either is, or thinks he is, not in a condition to follow up his victory with great results, and contents himself with merely fending off the danger and saving the honour of his arms. That the defender by inferiority of force and other circumstances may be tied down to that degree we do not dispute, but there is no doubt that this, which is only the consequence of a contingent necessity, has often been assumed to be the consequence of that part which every defender has to play: and thus in an absurd manner it has become a prevalent view of the defensive that its battles should really be confined to warding off the attacks of the enemy, and not directed to the destruction of the enemy. We hold this to be a prejudicial error, a regular substitution of the form for the thing itself; and we maintain unreservedly that in the form of war which we call defence, the victory may not only be more probable, but may also attain the same magnitude and efficacy as in the attack, and that this may be the case not only in the total result of all the combats which constitute campaign, but also in any particular battle, if the necessary degree of force and energy is not wanting.
CHAPTER X - Fortresses
Formerly, and up to the time of great standing armies, fortresses, that is castles and fortified towns, were only built for the defence and protection of the inhabitants. The baron, if he saw himself pressed on all sides, took refuge in his castle to gain time and wait a more favourable moment; and towns sought by their walls to keep off the passing hurricane of war. This simplest and most natural object of fortresses did not continue to be the only one; the relation which such a place acquired with regard to the whole country and to troops acting here and there in the country soon gave these fortified points a wider importance, a signification which made itself felt beyond their walls, and contributed essentially to the conquest or occupation of the country, to the successful or unsuccessful issue of the whole contest, and in this manner they even became a means of making war more of a connected whole. Thus fortresses acquired that strategic significance which for a time was regarded as so important that it dictated the leading features of the plans of campaigns, which were more directed to the taking of one or more fortresses than the destruction of the enemy’s army in the field. Men reverted to the cause of the importance of these places, that is to the connection between a fortified point, and the country, and the armies; and then thought that they could not be sufficiently particular or too philosophical in choosing the points to be fortified. In these abstract objects the original one was almost lost sight of, and at length they came to the idea of fortresses without either towns or inhabitants.
On the other hand, the times are past in which the mere enclosure of a place with walls, without any military preparations, could keep a place dry during an inundation of war sweeping over the whole country. Such a possibility rested partly on the division of nations formerly into small states, partly on the periodical character of the incursions then in vogue, which had fixed and very limited duration, almost in accordance with the seasons, as either the feudal forces hastened home, or the pay for the condottieri used regularly to run short. Since large standing armies, with powerful trains of artillery mow down the opposition of walls or ramparts as it were with a machine, neither town nor other small corporation has any longer an inclination to hazard all their means only to be taken a few weeks or months later, and then to be treated so much the worse. Still less can it be the interest of an army to break itself up into garrisons for a number of strong places, which may for a time retard the progress of the enemy, but must in the end submit. We must always keep enough forces, over and above those in garrison, to make us equal to the enemy in the open field, unless we can depend on the arrival of an ally, who will relieve our strong places and set our army free. Consequently the number of fortresses has necessarily much diminished, and this has again led to the abandonment of the idea of directly protecting the population and property in towns by fortifications, and promoted the other idea of regarding the fortresses as an indirect protection to the country, which they secure by their strategic importance as knots which hold together the strategic web.
Such has been the course of ideas, not only in books but also in actual experience, at the same time, as usually happens, it has been much more spun out in books.
Natural as was this tendency of things, still these ideas were carried out to an extreme, and mere crotchets and fancies displaced the sound core of a natural and urgent want. We shall look into these simple and important wants when we enumerate the objects and conditions of fortresses all together; we shall thereby advance from the simple to the more complicated, and in the succeeding chapter we shall see what is to be deduced therefrom as to the determination of the position and number of fortresses.
The efficacy of a fortress is plainly composed of two different elements, the passive and the active. By the first it shelters the place, and all that it contains; by the other it possesses a certain influence over the adjacent country, even beyond the range of its guns.
This active element consists in the attacks which the garrison may undertake upon every enemy who approaches within a certain distance. The larger the garrison, so much the stronger numerically will be the detachments that may be employed on such expeditions, and the stronger such detachments the wider as a rule will be the range of their operations; from which it follows that the sphere of the active influence of a great fortress is not only greater in intensity but also more extensive than that of a small one. But the active element itself is again, to a certain extent, of two kinds, consisting namely of enterprises of the garrison proper, and of enterprises which other bodies of troops, great and small, not belonging to the garrison but in co-operation with it, may be able to carry out. For instance, corps which independently would be too weak to face the enemy, may, through the shelter which, in case of necessity, the walls of a fortress afford them, be able to maintain themselves in the country, and to a certain extent to command it.
The enterprises which the garrison of a fortress can venture to undertake are always somewhat restricted. Even in the case of large places and strong garrisons, the bodies of troops which can be employed on such operations are mostly inconsiderable as compared with the forces in the field, and their average sphere of action seldom exceeds a couple of days’ marches. If the fortress is small, the detachments it can send out are quite insignificant and the range of their activity will generally be confined to the nearest villages. But corps which do not belong to the garrison, and therefore are not under the necessity of returning to the place, are thereby much more at liberty in their movements, and by their means, if other circumstances are favourable, the external zone of action of a fortress may be immensely extended. Therefore if we speak of the active influence of fortresses in general terms, we must always keep this feature of the same principally in view.
But even the smallest active element of the weakest garrison, is still essential for the different objects which fortresses are destined to fulfil, for strictly speaking even the most passive of all the functions of a fortress (defence against attack) cannot be imagined exclusive of that active agency. At the same time it is evident that amongst the different purposes which a fortress may have to answer generally, or in this or that moment, the passive element will be most required at one time, the active at another. The role which a fortress is to fulfil may be perfectly simple, and the action of the place will in such case be to a certain extent direct; it may be partly complicated, and the action then becomes more or less indirect. We shall examine these subjects separately, commencing with the first; but at the outset we must state that a fortress may be intended to answer several of these purposes, perhaps all of them, either at once, or at least at different stages of the war.
We say, therefore, that fortresses are great and most important supports of the defensive.
1. As secure depots of stores of all kinds. The assailant during his aggression subsists his army from day to day; the defensive usually must have made preparations long beforehand, he need not therefore draw provisions exclusively from the district he occupies, and which he no doubt desires to spare. Storehouses are therefore for him a great necessity. The provisions of all kinds which the aggressor possesses are in his rear as he advances, and are therefore exempt from the dangers of the theatre of war, while those of the defensive are exposed to them. If these provisions of all kinds are not in fortified places, then a most injurious effect on the operations in the field is the consequence, and the most extended and compulsory positions often become necessary in order to cover depots or sources of supply.
An army on the defensive without fortresses has a hundred vulnerable spots; it is a body without armour.
2. As a protection to great and wealthy towns. This purpose is closely allied to the first, for great and wealthy towns, especially commercial ones, are the natural storehouses of an army; as such their possession and loss affects the army directly. Besides this, it is also always worth while to preserve this portion of the national wealth, partly on account of the resources which they furnish directly, partly because, in negotiations for peace, an important place is in itself a valuable weight thrown into the scale.
This use of fortresses has been too little regarded in modern times, and yet it is one of the most natural, and one which has a most powerful effect, and is the least liable to mistakes. If there was a country in which not only all great and rich cities, but all populous places as well were fortified, and defended by the inhabitants and the people belonging to the adjacent districts, then by that means the expedition of military operation would be so much reduced, and the people attacked would press with so great a part of their whole weight in the scales, that the talent as well as the force of will of the enemy’s general would sink to nothing.
We just mention this ideal application of fortification to a country to do justice to what we have just supposed to be the proper use of fortresses, and that the importance of the direct protection which they afford may not be overlooked for a moment; but in any other respect this idea will not again interrupt our considerations, for amongst the whole number of fortresses there must always be some which must be more strongly fortified than others, to serve as the real supports of the active army.
The purposes specified under 1 and 2 hardly call forth any other but the passive action of fortresses.
3. As real barriers, they close the roads, and in most cases the rivers, on which they are situated.
It is not as easy as is generally supposed to find a practicable lateral road which passes round a fortress, for this turning must be made, not only out of reach of the guns of this place, but also by a detour greater or less, to avoid sorties of the garrison.
If the country is in the least degree difficult, there are often delays connected with the slightest deviation of the road which may cause the loss of a whole day’s march, and, if the road is much used, may become of great importance.
How they may have an influence on enterprises by closing the navigation of a river is clear in itself.
4. As tactical points d’appui. As the diameter of the zone covered by the fire of even a very inferior class of fortifications is usually some leagues, fortresses may be considered always as the best points d’appui for the flanks of a position. A lake of several miles long is certainly an excellent support for the wing of an army, and yet a fortress of moderate size is better. The flank does not require to rest close upon it, as the assailant, for the sake of his retreat, would not throw himself between our flank and that obstacle.
5. As a station (or stage). If fortresses are on the line of communication of the defensive, as is generally the case, they serve as halting places for all that passes up and down these lines. The chief danger to lines of communication is from irregular bands, whose action is always of the nature of a shock. If a valuable convoy, on the approach of such a comet, can reach a fortress by hastening the march or quickly turning, it is saved, and may wait there till the danger is past. Further, all troops marching to or from the army, after halting here for a a few days, are better able to hasten the remainder of the march, and a halting day is just the time of greatest danger. In this way a fortress situated half way on a line of communication of 30 miles shortens the line in a manner one half.
6. As places of refuge for weak or defeated corps. Under the guns of a moderate sized fortress every corps is safe from the enemy’s blows, even if no entrenched camp is specially prepared for them. No doubt such a corps must give up its further retreat if it waits too long; but this is no great sacrifice in cases where a further retreat would only end in complete destruction.
In many cases a fortress can ensure a few days’ halt without the retreat being altogether stopped. For the slightly wounded and fugitives who precede a beaten army, it is especially suited as a place of refuge, where they can wait to rejoin their corps.
If Magdeburg had lain on the direct line of the Prussian retreat in 1806, and if that line had not been already lost at Auerstadt, the army could easily have halted for three or four days near that great fortress, and rallied and reorganised itself. But even as it was it served as a rallying point for the remains of Hohenlohe’s corps, which there first resumed the appearance of an army.
It is only by actual experience in war itself that the beneficial influence of fortresses close at hand in disastrous times can be rightly understood. They contain powder and arms, forage and bread, give covering to the sick, security to the sound, and recovery of sense to the panic-stricken. They are like an hostelry in the desert.
In the four last named purposes it is evident that the active agency of fortresses is called more into requisition.
7. As a real shield against the enemy’s aggression. Fortresses which the defender leaves in his front break the stream of the enemy’s attack like blocks of ice. The enemy must at least invest them, and requires for that, if the garrisons are brave and enterprising, perhaps double their strength. But, besides, these garrisons may and do mostly consist in part of troops, who, although competent to duty in a garrison, are not fit for the field—half trained militia, invalids, convalescents, armed citizens, landsturm, etc. The enemy, therefore, in such case is perhaps weakened four times more than we are.
This disproportionate weakening of the enemy’s power is the first and most important but not the only advantage which a besieged fortress affords by its resistance. From the moment that the enemy crosses our line of fortresses, all his movements become much more constrained; he is limited in his lines of retreat, and must constantly attend to the direct covering of the sieges which he undertakes.
Here, therefore, fortresses co-operate with the defensive act in a most extensive and decisive manner, and of all the objects that they can have, this may be regarded as the most important.
If this use of fortresses—far from being seen regularly repeating itself—seldom comparatively occurs in military history, the cause is to be found in the character of most wars, this means being to a certain extent far too decisive and too thoroughly effectual for them, the explanation of which we leave till hereafter.
In this use of fortresses it is chiefly their offensive power that is called for, at least it is that by which their effectual action is chiefly produced. If a fortress was no more to an aggressor than a point which could not be occupied by him, it might be an obstacle to him, but not to such a degree as to compel him to lay siege to it But as he cannot leave six, eight, or ten thousand men to do as they like in his rear, he is obliged to invest the place with a sufficient force, and if he desires that this investment should not continue to employ so large a detachment, he must convert the investment into a siege, and take the place. From the moment the siege commences, it is then chiefly the passive efficacy of the fortress which comes into action.
All the destinations of fortresses which we have been hitherto considering are fulfilled in a simple and mainly in a direct manner. On the other hand, in the next two objects the method of action is more complicated.
8. As a protection to extended cantonments. That a moderate-sized fortress closes the approach to cantonments lying behind it for a width of three or four milesis a simple result of its existence; but how such a place comes to have the honour of covering a line of cantonments fifteen or twenty miles in length, which we find frequently spoken of in military history as a fact—that requires investigation as far as it has really taken place, and refutation so far as it may be mere illusion.
The following points offer themselves for consideration:—
(1.) That the place in itself blocks one of the main roads, and really covers a breadth of three or four miles of country.
(2.) That it may be regarded as an exceptionally strong advanced post, or that it affords a more complete observation of the country, to which may be added facilities in the way of secret information through the ordinary relations of civil life which exist between a great town and the adjacent districts It is natural that in a place of six, eight or ten thousand inhabitants, one should be able to learn more of what is going on in the neighbourhood than in a mere village, the quarters of an ordinary outpost.
(3.) That smaller corps are appuyed on it, derive from it protection and security, and from time to time can advance towards the enemy, it may be to bring in intelligence, or, in case he attempts to turn the fortress, to underdertake something against his rear; that therefore although a fortress, cannot quit its place, still it may have the efficacy of an advanced corps (Fifth Book, eighth Chapter).
(4.) That the defender, after assembling his corps, can take up his position at a point directly behind this fortress, which the assailant cannot reach without becoming exposed to danger from the fortress in his rear.
No doubt every attack on a line of cantonments as such is to be taken in the sense of a surprise, or rather, we are only speaking here of that kind of attack; now it is evident in itself that an attack by surprise accomplishes its effect in a much shorter space of time than a regular attack on a theatre of war. Therefore, although in the latter case, a fortress which is to be passed by must necessarily be invested and kept in check, this investment will not be so indispensable in the case of a mere sudden attack on cantonments, and therefore in the same proportion the fortress will be less an obstacle to the attack of the cantonments. That is true enough; also the cantonments lying at a distance of six to eight miles from the fortress cannot be directly protected by it; but the object of such a sudden attack does not consist alone in the attack of a few cantonments. Until we reach the book on attack we cannot describe circumstantially the real object of such a sudden attack and what may be expected from it; but this much we may say at present, that its principal results are obtained, not by the actual attack on some isolated quarters, but by the series of combats which the aggressor forces on single corps not in proper order, and more bent upon hurrying to certain points than upon fighting. But this attack and pursuit will always be in a direction more or less towards the centre of the enemy’s cantonments, and, therefore, an important fortress lying before this centre will certainly prove a very great impediment to the attack.
If we reflect on these four points in the whole of their effects, we see that an important fortress in a direct and in an indirect way certainly gives some security to a much greater extent of cantonments than we should think at first sight. “Some security” we say, for all these indirect agencies do not render the advance of the enemy impossible; they only make it more difficult, and a more serious consideration; consequently less probable and less of a danger for the defensive. But that is also all that was required, and all that should be understood in this case under the term covering. The real direct security must be attained by means of outposts and the arrangement of the cantonments themselves.
There is, therefore, some truth in ascribing to a great fortress the capability of covering a wide extent of cantonments lying in rear of it; but it is also not to be denied that often in plans of real campaigns, but still oftener in historical works, we meet with vague and empty expressions, or illusory views in connection with this subject. For if that covering is only realised by the co-operation of several circumstances, if it then also only produces a diminution of the danger, we can easily see that, in particular cases, through special circumstances, above all, through the boldness of the enemy, this whole covering may prove an illusion, and therefore in actual war we must not content ourselves with assuming hastily at once the efficacy of such and such a fortress, but carefully examine and study each single case on its own merits.
9. As covering a province not occupied. If during war province is either not occupied at all, or only occupied by an insufficient force, and likewise exposed more or less to incursions from flying columns, then a fortress, if not too unimportant in size, may be looked upon as a covering, or, if we prefer, as a security for this province. As a security it may at all events be regarded, for an enemy cannot become master of the province until he has taken it, and that gives us time to hasten to its defence. But the actual covering can certainly only be supposed very indirect, or as not preperly belonging to it. That is, the fortress by its active opposition can only in some measure check the incursions of hostile bands. If this opposition is limited to merely what the garrison can effect, then the result must be little indeed, for the garrisons of such places are generally weak and usually consist of infantry only, and that not of the best quality. The idea gains a little more reality if small columns keep themselves in communication with the place, making it their base and place of retreat in case of necessity.
10. As the focus of a general arming of the nation. Provisions, arms, and munitions can never be supplied in a regular manner in a People’s War; on the other hand, it is just in the very nature of such a war to do the best we can; in that way a thousand small sources furnishing means of resistance are opened which otherwise might have remained unused; and it is easy to see that a strong commodious fortress, as a great magazine of these things, can well give to the whole defence more force and intensity, more cohesion, and greater results.
Besides, a fortress is a place of refuge for wounded, the seat of the civil functionaries, the treasury, the point of assembly for the greater enterprises, etc., etc.; lastly, a nucleus of resistance which during the siege places the enemy’s force in a condition which facilitates and favours the attacks of national levies acting in conjunction.
11. For the defence of rivers and mountains. Nowhere can a fortress answer so many purposes, undertake to play so many parts, as when it is situated on a great river. It secures the passage at any time at that spot, and hinders that of the enemy for several miles each way, it commands the use of the river for commercial purposes, receives all ships within its walls, blocks bridges and roads, and helps the indirect defence of the river, that is, the defence by a position on the enemy’s side. It is evident that, by its influence in so many ways, it very greatly facilitates the defence of the river, and may be regarded as an essential part of that defence.
Fortresses in mountains are important in a similar manner. They there form the knots of whole systems of roads, which have their commencement and termination at that spot; they thus command the whole country which is traversed by these roads, and they may be regarded as the true buttresses of the whole defensive system.
CHAPTER XI - Fortresses (Continued)
We have discussed the object of fortresses: now for their situation. At first the subject seems very complicated, when we think of the diversity of objects, each of which may again be modified by the locality; but such a view has very little foundation if we keep to the essence of the thing, and guard against unnecessary subtilties.
It is evident that all these demands are at once satisfied, if, in those districts of country which are to be regarded as the theatre of war, all the largest and richest towns on the great high roads connecting the two countries with each other are fortified, more particularly those adjacent to harbours and bays of the sea, or situated on large rivers and in mountains. Great towns and great roads always go hand in hand, and both have also a natural connection with great rivers and the coasts of the sea, all these four conditions, therefore, agree very well with each other, and give rise to no incongruity; on the other hand, it is not the same with mountains, for large towns are seldom found there. If, therefore, the position and direction of a mountain chain makes it favourable to a defensive line, it is necessary to close its roads and passes by small forts, built for this purpose only, and at the least possible cost, the great outlay on works of fortification being reserved for the important places of arms in the level country.
We have not yet noticed the frontiers of the state, nor said anything of the geometrical form of the whole system of fortresses, nor of the other geographical points in connection with their situation, because we regard the objects above mentioned as the most essential, and are of opinion that in many cases they alone are sufficient, particularly in small states. But, at the same time, other considerations may be admitted, and may be imperative in countries of a greater superficial extent, which either have a great many important towns and roads, or, on the contrary, are almost without any, which are either very rich, and, possessing already many fortresses, still want new ones, or those which, on the other hand, are very poor, and under the necessity of making a few answer, in short, in cases where the number of fortresses does not correspond with the number of important towns and roads which present themselves, being either considerably greater or less.
We shall now cast a glance at the nature of such other considerations.
The chief questions which remain relate to
1. The choice of the principal roads, if the two countries are connected by more roads than we wish to fortify.
2. Whether the fortresses are to be placed on the frontier only, or spread over the country. Or,
3. Whether they shall be distributed uniformly, or in groups.
4. Circumstances relating to the geography of the country to which it is necessary to pay attention.
A number of other points with respect to the geometrical form of the line of fortifications, such as whether they should be placed in a single line or in several lines, that is, whether they do more service when placed one behind another, or side by side in line with each other; whether they should be chequer-wise, or in a straight line; or whether they should take the form of a fortification itself, with salients and re-entering angles all these we look upon as empty subtilties, that is, considerations so insignificant, that, compared with the really important points, they are not worth notice; and we only mention them here because they are not merely treated of in many books, but also a great deal more is made of this rubbish than it is worth.
As regards the first question, in order to place it in a clearer light we shall merely instance the relation of the south of Germany to France, that is, to the upper Rhine. If, without reference to the number of separate states composing this district of country, we suppose it a whole which is to be fortified strategically, much doubt will arise, for a great number of very fine roads lead from the Rhine into the interior of Franconia, Bavaria and Austria. Certainly, towns are not wanting which surpass others in size and importance, as Nuremburg, Wurzburg, Ulm, Augsburg, and Munich; but if we are not disposed to fortify all, there is no alternative but to make a selection. If, further, in accordance with our view, the fortification of the greatest and wealthiest is held to be the principal thing, still it is not to be denied that, owing to the distance between Nuremburg and Munich, the first has a very different strategic signification from the second; and therefore it always remains to be considered whether it would not be better, in place of Nuremburg, to fortify some other place in the neighbourhood of Munich, even if the place is one of less importance in itself.
As concerns the decision in such cases, that is, answering the first question, we must refer to what has been said in the chapters on the general plan of defence, and on the choice of points of attack. Wherever the most natural point of attack is situated, there the defensive arrangements should be made by preference.
Therefore, amongst a number of great roads leading from the enemy’s country into ours, we should first of all fortify that which leads most directly to the heart of our dominions, or that which, traversing fertile provinces, or running parallel to navigable rivers, facilitates the enemy’s undertaking, and then we may rest secure. The assailant then encounters these works, or should he resolve to pass them by, he will naturally offer a favourable opportunity for operations against his flank.
Vienna is the heart of South Germany, and plainly Munich or Augsburg, in relation to France alone (Switzerland and Italy being therefore supposed neutral) would be more efficient as a principal fortress than Nuremburg or Wurzburg. But if, at the same time, we look at the roads leading from Italy into Germany by Switzerland and the Tyrol, this will become still more evident, because, in relation to these, Munich and Augsburg will always be places of importance, whereas Wurzburg and Nuremburg are much the same, in this respect, as if they did not exist.
We turn now to the second question Whether the fortresses should be placed on the frontier, or distributed over the country? In the first place, we must observe, that, as regards small states, this question is superfluous, for what are called strategic frontiers coincide, in their case, nearly with the whole country. The larger the state is supposed to be in the consideration of this question, the plainer appears the necessity for its being answered.
The most natural answer is, that fortresses belong to the frontiers, for they are to defend the state, and the state is defended as long as the frontiers are defended. This argument may be valid in the abstract, but the following considerations will show that it is subject to very many modifications.
Every defence which is calculated chiefly on foreign assistance lays great value on gaining time; it is not a vigorous counterstroke, but a slow proceeding, in which the chief gain consists more in delay than in any weakening of the enemy which is effected. But now it lies in the nature of the thing that, supposing all other circumstances alike, fortresses which are spread over the whole country, and include between them a very considerable area of territory, will take longer to capture than those squeezed together in a close line on the frontier. Further, in all cases in which the object is to overcome the enemy through the length of his communications, and the difficulty of his existence therefore in countries which can chiefly reckon on this kind of reaction, it would be a complete contradiction to have the defensive preparations of this kind only on the frontier. Lastly, let us also remember that, if circumstances will in any way allow of it, the fortification of the capital is a main point; that according to our principles the chief towns and places of commerce in the provinces demand it likewise; that rivers passing through the country, mountains, and other irregular features of ground, afford advantages for new lines of defence; that many towns, through their strong natural situation, invite fortification; moreover, that certain accessories of war, such as manufactories of arms, &c., are better placed in the interior of the country than on the frontier, and their value well entitles them to the protection of works of fortification; then we see that there is always more or less occasion for the construction of fortresses in the interior of a country; on this account we are of opinion, that although states which possess a great number of fortresses are right in placing the greater number on the frontier, still it would be a great mistake if the interior of the country was left entirely destitute of them. We think that this mistake has been made in a remarkable degree in France. A great doubt may with reason arise if the border provinces of a country contain no considerable towns, such towns lying further back towards the interior, as is the case in South Germany in particular, where Swabia is almost destitute of great towns, whilst Bavaria contains a large number. We do not hold it to be necessary to remove these doubts once for all on general grounds, believing that in such cases, in order to arrive at a solution, reasons derived from the particular situation must come into consideration. Still we must call attention to the closing remarks in this chapter.
The third question Whether fortresses should be disposed in groups, or more equally distributed? will, if we reflect upon it, seldom arise; still we must not, for that reason, set it down as a useless subtilty, because certainly a group of two, three, or four fortresses, which are only a few days’ march from a common centre, give that point and the army placed there such strength, that, if other conditions allowed of it, in some measure one would be very much tempted to form such a strategic bastion.
The last point concerns the other geographical properties of the points to be chosen. That fortresses on the sea, on streams and great rivers, and in mountains, are doubly effective, has been already stated to be one of the principal considerations; but there are a number of other points in connection with fortresses to which regard must be paid.
If a fortress cannot lie on the river itself, it is better not to place it near, but at a distance of ten or twelve miles from it; otherwise, the river intersects, and lowers the value of the sphere of action of the fortress in all those points above mentioned.(*)
This is not the same in mountains, because there the movement of large or small masses upon particular points is not restricted in the same degree as it is by a river. But fortresses on the enemy’s side of a mountain are not well placed, because they are difficult to succour. If they are on our side, the difficulty of laying siege to them is very great, as the mountains cut across the enemy’s line of communication. We give Olmütz, 1758, as an example.
It is easily seen that impassable forests and marshes have a similar effect to that of rivers.
The question has been often raised as to whether towns situated in a very difficult country are well or ill suited for fortresses. As they can be fortified and defended at a small expense, or be made much stronger, often impregnable, at an equal expenditure, and the services of a fortress are always more passive than active, it does not seem necessary to attach much importance to the objection that they can easily be blockaded.
If we now, in conclusion, cast a retrospective glance over our simple system of fortification for a country, we may assert that it rests on comprehensive data, lasting in their nature, and directly connected with the foundations of the state itself, not on transient views on war, fashionable for a day; not on imaginary strategic niceties, nor on requirements completely singular in character an error which might be attended with irreparable consequences if allowed to influence the construction of fortresses intended to last five hundred, perhaps a thousand, years. Silberberg, in Silesia, built by Frederick the Great on one of the ridges of the Sudetics, has, from the complete alteration in circumstances which has since taken place, lost almost entirely its importance and object, whilst Breslau, if it had been made a strong place of arms, and continued to be so, would have always maintained its value against the French, as well as against the Russians, Poles, and Austrians.
Our reader will not overlook the fact that these considerations are not raised on the supposed case of a state providing itself with a set of new fortifications; they would be useless if such was their object, as such a case seldom, if ever, happens; but they may all arise at the designing of each single fortification.
(*) Philippsburg was the pattern of a badly-placed fortress; it resembled a fool standing with his nose close to a wall.
