Book V is a case study of the armed forces, not of their employment in battle, but rather how they are organized and their “relationship to country and terrain”. It rather like describing how each chess piece is allowed to move on the board, less about how it is used in actual play.
Book V, like all of On War, has many points of interest. In particular, it is a good example of Clausewitz’s own method of analysis, and thinking through how the various elements of the “modern” military forces of his day actually worked. This approach could be fruitfully emulated by application to modern militaries. However, since it is a “drill down” on armies as they were in Clausewitz’s own day it contains a relatively lower proportion of “high grade ore” than some of the other books, particularly the refined material in Book I.
In Chapter 2, entitled “Relative Strength”, Clausewitz reiterates his theme that the armies of his day, in his part of the world, were “so much alike in weapons, training and equipment that there is little difference in such matters between the best and the worst of them.” Hence, what we would now call asymmetry was not an issue for Clausewitz. He does not focus on one side having any technological advantage. As soon a soon as “one side invents improvements and first puts them to use … the other side promptly copies them.” Clausewitz has no notion that a technological advantage could be so major, and come along so swiftly, that it could decide a battle, campaign or war before the other side obtained it. The tempo and importance of technological change in our era have made this a much bigger factor.
The only other thing that can give one army an advantage over another is “the talents of the commander in chief”. However,he believes this to be “completely left to chance”.
Therefore, what matters most, among the factors that can be contrlled, is the sheer size of the army.
Of course, Clausewitz, proceeds in his characteristic fashion — “X is the case! However, do not mistake me as pedantically saying that Not-X may not sometimes be the case under the proper circumstances.” Clausewitz tells us that inferior numbers may sometimes prevail by waging struggles of “limited goals” or “limited duration”. He also notes:
Where the weaker side is forced to fight against odds, its lack of numbers must be made up by the inner tension and vigor that is inspired by danger. Where the opposite ocurs, and despair engenders dejection instead of heroism, the art of war has, of course, come to an end.
He uses the example of Frederick the Great, who fought from a position of weakness, but who struck sharp, highly focused blows, and fended off his enemies with victories in major battles.
In the modern era, we see physically weaker armies prevailing due to having limited goals and superior “inner tension and vigor” — but they do so not by brief campaigns, but protracted ones. Such militaries, or rather politico-military organizations, acceptthe hardship that fighting from weaknesses imposes, or even turn the suffering of their peoples into an advantage, by aiming at directly political and moral ends rather than strictly military victories.
I will note a few other things that struck me about Book V.
The chapter on maintainence and supply (chapter 14) observes that the modern method is to live off of the territory where the army is operating. This works best in wealthy countries, less so in poor ones. Napoleon was able to march rapidly and win major victories in places where his armies could plunder ample provisions. In Poland (1807) and Russia (1812) this was less possible, and Napoleon met with either stalemate or failure. The Germans “lived off the land” to a large degree in their later wars, and had the same experience. (See, e.g. Citino’s The German Way of War and van Creveld’s Supplying War.) Clausewitz has no notion of projecting power by sea. He has little notion of maintaining large forces in remote locations by means of water carriage. And of course Clausewitz died just before the dawn of the era of motor transport. He could not have conceived of the logistical effort undertaken by the maritime powers, Britain and the USA, in the 20th century and down to the present day.
Clausewitz’s discussion of terrain (Chapter 17) contains some timely observations. He notes that an army composed of a “population in arms” can only exist only in “heavily uneven and broken terrain” — woods, mountains, cities. But such armies will lack the “qualities and virtues” and also the physical capacity, for concentrated action. He notes that even a standing professional army will take on the character of a national army when fighting on its own soil, permitting “greater independence of action”. In other words, dispersal is less of a problem for the defender in such circumstances. He notes that troops are competent to fight as a concentrated mass are at a disadvantage fighting such armies, in such terrain, and that they try not to allow themselves to be dispersed, but are forced to do so. Clausewitz would not have been surprised by the way that modern guerilla-style war has played out. He had already seen it in embryonic form in his own day.
There are many more such insights in Book VI, Defense — coming up next.
(JosephFouche‘s discussion of Book V is remarkable. He looks at the entire book in terms of the freedom of action of the commander, with all considerations turning on maximizing that freedom. I read Book V and did not see this angle at all, but he is certainly right about it. This, to me, is a good example of the value of this group discussion, whatever others may take from it.)