In book three, Clausewitz gives us a breakdown of his theory of strategy. Early on, he roughly defines strategy as “the use of engagement for the purpose of war” (p. 177). By this Clausewitz is telling us that the individual engagements are the means to the end, and the strategist must therefore understand how to apply the individual engagements to achieve the desired goal. It is a high level view of the overall theater of operations, while tactics concerns its self with actions inside the individual engagement.
Clausewitz goes on to divide the factors involved in strategy in to five general categories, focusing mainly on the ideas of the moral or psychological, and the physical. While he briefly mentions the other elements, mathematical, geographical and statistical, his main point in these areas is that they have little effect on the outcome at a strategic level.
I find Clausewitz’ view of the “moral” to be particularly fascinating. Clausewitz puts the most emphasis on the psychology of the army, and perhaps rightly so. More specifically, he puts a high value on discipline and the esprit de corps of professional soldiers (p.187). At a strategic level then, it is better to have well trained, highly disciplined professional soldiers, with a history of success on the battlefield, then an angry mob of patriots who come streaming out of the woods and hills looking for a fight. It might appear to some that these two groups would be on equal footing, and I conjecture that one would not have to look far to find examples of fanaticism leading combatants to great feats. However the difference, as Clausewitz points out, is that professional soldiers are apt to maintain a high level of discipline and professionalism under fire. This makes them able to withstand situations that are less than optimal, and more tolerant of mistakes in leadership (p. 187, 188).
Clausewitz’ other big point in this book deals with the “physical”, which translates roughly to troop strength. Clausewitz’ theory here is simple, “As big as possible”. Strategically, Clausewitz advocates applying as much force as possible to theater, overwhelming the enemy (p.195). He doesn’t have much use for reserves or dividing forces at this level of operations, though both have their place tactically.
Clausewitz is quick to point out that these two factors, along with the other three that are mentioned in the introduction but not covered in as great detail, are not always necessary to win a war. The implication though appears to be that the more factors that a force possesses, the greater the chance of victory. It would seem to follow that a large force of highly disciplined professional soldiers should be the goal of every nation.