The Culminating Point of Victory
Secondly, I select his doctrine of the culminating point of victory, because that is essential in order to understand his division of all wars into two classes, according to how far the attack is likely to be able to extend into the hostile country before reaching its culminating point, where reaction may set in.[20]
"The conqueror in a war is not always in a condition to subdue his adversary completely. Often, in fact almost universally, there is a culminating point of victory. Experience shows this sufficiently."[21] As the attack or invasion progresses it becomes weaker even from its successes, from sieges or corps left to observe fortified places, from the troops required to guard the territory gained, and the lengthening line of communications, from the fact that we are removing further from our resource while the enemy is falling back upon and drawing nearer to his, from the danger of other States joining in to prevent the utter destruction of the defeated nation, from the rousing of the whole nation in extremity to save themselves by a people's war, from the slackening of effort in the victorious army itself, etc., etc. Leoben, Friedland, Austerlitz, Moscow, are instances of such a culminating point, and probably in the late Russo-Japanese war Harbin would have proved so, too, if peace had not intervened.
Clausewitz continues: "It is necessary to know how far it (our preponderance) will reach, in order not to go beyond that point and, instead of fresh advantage, reap disaster." He defines it as "The point at which the offensive changes into the defensive," and says, "to overstep this point is more than simply a useless expenditure of power yielding no further results, it is a destructive step which causes reaction, and the reaction is, according to all experience, productive of most disproportionate effects."[22] The reader will find it an interesting exercise to search for this culminating point of victory in historical campaigns, and mark the result where it has been overstepped and where it has not been overstepped.