Clausewitz clearly lays down: "_War is only a continuation of State policy by other means._ This point of view being adhered to will introduce much more unity into the consideration of the subject, and things will be more easily disentangled from each other."[18] "It is only thus that we can obtain a clear conception of war, for the political view is the _object_, war is the _means_, and the means must always include the object in our conception." "Each (nation or government) strives by physical force to compel the other to submit to its will."[19] Owing to the great importance of this point of view, so little understood in this country, I have devoted the next chapter to it alone, so as to bring out Clausewitz's view more in detail. We can, therefore, pass on for the present. 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. THE TWO CLASSES OF WARS