Page:Encyclopædia Britannica, Ninth Edition, v. 24.djvu/374

350 WAR [STRATEGY. Fresh supplies of ammunition at least must be continually received from a secure source, and the means must be available for feeding the army in case the resources of the country fail. Nowadays, and in most countries, the main line of supply is carried along lines of railway ; but, as these are always liable to be destroyed by a retreating enemy, transport, independent of that which is required merely for distribution, must be provided in the form of waggons, carts, or pack animals sufficient to supply, for at least some days, the entire army. Line of The source from which an army is supplied is usually comnm- spoken of as its "base" or its "base of supply." The uications. j[ rec tion in which, looking forward, a general proposes to advance, and along which it will be necessary to arrange for supply, is spoken of as his "line of operations." The direction along which the army, having already advanced to some distance from its base, is supplied, is spoken of as its "line of communications." Now, as the line of com munications may come to be of great length as an army advances, and as the army needs to have its fighting strength available in the front when it is engaged with the enemy, it is clear that the long lines of road or rail way along which the food and ammunition are moving forward, while parties of sick and wounded men are going backward, become weak points in its condition, which must be jealously guarded, but are difficult adequately to protect throughout their length, without detracting too much from the force in the front. In modern war the effort of the general is directed to maintaining in its full efficiency " the vast and complicated machine " which he handles, and to breaking up and destroying the efficiency of that to which he is opposed. This is the central fact to be kept in mind. Generals and soldiers, long accus tomed to look at war from this point of view, frequently embody their whole conception of strategy in a phrase which to a reader, taking it in its simple form, is apt to seem like a mere truism that the great principle of strategy is to concentrate the largest possible force at the right moment at the decisive point. So stated, strategy may seem to have nothing exceptional in its nature, and to in volve no study of the nature of the great organizations of men with which it is concerned. But, in fact, this study and this knowledge are presupposed by those who thus explain their art. It is because armies are not mere gatherings of armed men, but have a vitality of their own, that some very heavy blows may be struck against them without affecting a vital point, whilst a more skilfully directed stroke may destroy their whole future power of action. An army then, as it stands in the field, is of this character, that, while the fighting force directly opposed to the enemy is an organism which depends for its vitality upon the trained spirit of order, discipline, and enthusiasm or devotion which holds it together, and on the trained capacity for mutual and effective fighting co-operation which makes it act like one man, it has also, reaching far behind it, a long and weak tail, on the safety of which its very existence depends. Now, if by employing a large portion, or the whole of his own force, against a smaller portion of the enemy s, a general can break up and defeat it, the advantage gained depends on the fact that he has broken up the organic unity of this portion. Even if, as may easily happen, he has lost more men than the enemy during the effort, that very little affects the importance of the result on the future of the campaign. The strength of armies cannot be measured by counting heads within the theatre of war. It depends upon the organized force that the general is able to use and to direct. During the earlier battles of the 1870 campaign, for instance, the Germans lost very many more men than the French, but at Weissenburg they broke up the organic efficiency of a French division of about 8000 men. At Worth they broke up the organic efficiency of 40,000 men at least. After Worth the French army which had fought there had for the time being ceased to be an eliective fighting body at all. Throughout the campaign it never recovered efficiency. The German forces, on the other hand, though they had lost more fight ing men than the French, had actually increased their own effective power. Their organic unity was retained, and the spirit which inspired it had been incalculably raised by victory. But if a general can in any way interfere with the source from which an enemy is obtaining his supplies of food, ammunition, and fresh men, he can diminish his fighting power as effectually as if he broke up the organic unity in battle. A body of men who are starving can as little be held in the bonds of organization as a body of men who are dispersed. Hence the slightest movement which threatens that long and weak tail already described obliges the general whose line of communications is threatened to take steps for its protection. At first sight it is not very obvious, since each army pos sesses lightly movable troops cavalry, mounted infantry, and the like why these should not be able to pass round the front of the opposing army, and get at the unguarded parts of the roads and railways along which the supplies are moving. To some extent, during the American civil war, this was actually done by the great leaders of horse men on either side,- Sheridan and Longstreet. In all probability a similar attempt will be made in future wars by the great bodies of Russian Cossacks, and perhaps by the cavalry of Germany, France, and Austria. But what facilitated the raids of the American cavalry of either army was the fact that they were moving in a country where all the people spoke the same language as themselves, and where they were sure to find sympathizers to supply them with needed information. Under ordinary circumstances the difficulty is that each army faces the other without any approach to complete knowledge of the distribution of the troops opposed to it. The part of the enemy s line of communication which is nearest to you is also the part nearest to the main body of that enemy s own army. In order to get at some parts of his communications which would be out of reach of support from the main army, it would be necessary to send the assailing light troops to points several marches in rear. This involves a long detour, an elaborately prepared march, and the risk that the enemy may become aware of what is designed. In fact, to use the forcible illustration which Clausewitz has employed to explain the situation in which the leader of such a raid finds himself, he is like a man entering a dark room full of assailants, never knowing when or whence a blow may be struck against him. The situation is altogether changed if, instead of the two armies fronting one another directly, one of the two is able to make its movements in such a way that, while it securely covers its own line of communications, its direct march forward threatens to strike the line of communica tions of the enemy. Then the light troops can at once strike the most exposed parts in all security. Under those circumstances the army whose communications are threatened is obliged immediately, for fear of losing its means of existence, to turn to face its opponents. The advantage so gained by the army which has obliged its enemy to conform to its movement is very great. For the choice of position can no longer be made by the assailed army solely with the view to gaining success in battle. It may be obliged to fight in a position tactically dis advantageous, and if it is defeated the defeat is almost certain to be fatal : for k will be driven away from the

means of replenishing supplies. On the other hand, the