“The duration of the combat under modern conditions,” writes General Négrier,[240] “leads to a considerable mental exhaustion of the troops which is apparent in nervous lassitude. This explains the impotency of leader and troops the day after a defeat and even after a victory. This lassitude is still greater on the day of the battle. While it is true that this has always been the case, the nervous exhaustion has grown in an inconceivable manner, its intensity increasing at the same rate as the invisibility of the opponent. _The invisibility of the enemy directly affects the morale of the soldier, the sources of his energy and courage. The soldier who cannot see his enemy is inclined to see him everywhere. It is but a step from this impression to hesitancy and then to fear._ The inertia of the troops for whole days at Magersfontain, Colenso, and Paardeberg, frequently more than 800 m. from the enemy, was not caused by their losses, but by the moral depression produced within the effective zone of rifle fire. Another factor, which governs the modern combat at short ranges, the _impossibility of the commander making his influence felt in lines which are seriously engaged_, is of still greater importance. _The influence of the officers who lead these lines is also limited. They are scarcely able to direct the three or four men nearest them._ The combat depends upon the individual fighters, and there never has been a time when the personal efficiency of the individual soldier has had a greater significance.” We should not forget that this change occurred during a period in which we no longer fight our battles with professional soldiers of long service, but, on the contrary, with peace cadres of our conscript armies raised to war strength by Reservists. [240] _Revue des deux mondes_, June number, 1902. Another factor to be considered is the fighting quality of the opponent. In an action against an enemy who is a match for us, the necessity for distribution in depth is, of course, greater than when fighting against poor troops. General v. Werder could with impunity oppose the newly raised levies of the French Republic on the =Lisaine= with 1.12 men per meter of front. The victory was won by this very extraordinary extension of front, which, if employed in the face of the Imperial army, would have led to defeat.[241] [241] KUNZ, _Entscheidungskämpfe des Korps Werder_, II, p. 11. _Considerations of importance in deciding upon the extent of front to be covered by a force, similar conditions on both sides being presumed, are_-- 1. _Whether it is compelled to fight an independent action alone_; 2. _Whether it is fighting, from the preparatory to the decisive stage of the combat, as part of a larger body, with at least one, or perhaps both flanks secured_; 3. _Whether it has been selected to make the decisive attack against an enemy already shaken by other troops_.