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 manœuvres 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.