CHAPTER VIATTACK OF A POSITION
Phases of the Attack.As we have already learned, the attack of a position by a unit comprises three phases:
The preparation of the attack.
The assault against the first hostile line.
The exploitation of the success by fighting in the interior of the position for its occupation.
These phases are the same as those in open ground warfare, but their importance, aspect, and order are not the same. Especially the preparation of a trench attack is such a preponderant phase of the attack that upon the manner of its execution depends the success of the attack. The exploitation of the success is a long and decisive operation. In trench warfare, the assault is only the beginning of the fighting for a position, and its purpose is to make a breach in the enemy’s first line. Through this breach, the reinforcing and reserve troops are pushed in behind the assaulting columns to deliver the real combat for the capture and occupation of the position.
Thus we see that the assault, which in open ground warfare is the final phase of the battle, is, on the contrary, in trench warfare the first move of the fight. In open warfare, the order of the battle is: the preparation, the approach march and infantry combat, and finally, the assault. An offensive in trench fighting consists of, first, the preparation; next, the assault against the first line; and last of all, the interior fighting for the position.
The cause of this reversion of the rôles of the attacking troops in a trench offensive operation lies in the strength and stability of the fortified front. It is impossible to maneuver against a continuous line which extends without a single breach. It is only possible to maneuver behind the first line or within the position after a breach has been made. If a part of the first line gives way before the pressure of the assailants, the leader of the attacking units pushes forward his troops through this breach without consideration of the strategical value of the part of the line broken.