Opportunities for restoring the battle and for turning impending defeat into a crushing victory are frequently offered during an engagement. General Lee's thin lines at Antietam or Sharpsburg (September 17, 1862), slowly fed by men jaded by heavy marching, were sorely pressed, but there was a lull in the Federal attack when Hooker's advance was checked. Had General McClellan at that moment thrown in "his last man and his last horse" in a vigorous reinforcing attack, Antietam would not have been a drawn battle, and Lee would not have retired at his leisure into Virginia. Lee's great victory at Chancellorsville (May 2-3, 1863), although marred by the accident which deprived him of Stonewall Jackson, was a striking instance of the success of the Defensive-Offensive system at the hands of a great commander, who defeated 90,000 troops with less than half that number, by a containing defence with 13,000 men and a decisive counter-stroke with the remainder.
But while this combined system is regarded by most authorities as the best, when circumstances warrant its adoption, it is the highest test of generalship to seize the right moment to pass from the guard to the thrust. This is the problem which confronted Marshal Foch, the generalissimo of the Allied Forces, during the great {49} German offensive movement on the Western Front in 1918. The defensive rôle endured from March 21 until July 17, 1918, and although many local counter-attacks were made along the whole battle front, the Allies did not pass from the guard to the thrust until the decisive counter-stroke was commenced in the Second Battle of the Marne (July 18, 1918) on a front of 27 miles from Fontenoy to Belleau, which drove the Germans back across the Marne on July 20.
THE SECOND BATTLE OF THE MARNE (July 18, 1918).—The great German offensive of March-June, 1918, was renewed on July 15, when the artillery preparation opened shortly after midnight and troops were poured across the Marne in small boats and over pontoon bridges. The attack was not unexpected. Adequate reserves were ready and in place, and a heavy counter-bombardment on the German troops in their positions of assembly, close to their front-line trenches, caused heavy casualties. The Germans succeeded in penetrating the French and American positions in parts of the 50-mile front to a maximum depth of 4 miles south-west of Reims, but on the Plains of Champagne little progress was made and the attack lost its momentum. During the attack of March 21, 1918, the advance was not held up until it was within striking distance of its ultimate objective, and the offensive on the Aisne in May, 1918, secured an advance of 12 miles. Captured documents showed that the attack of July east of Reims was intended to reach the Marne at Eperney and Chalons, an advance of 21 miles. A feature of the earlier days of the battle was a spirited counter-attack near Fossoy (on the extreme left of the German forces) by a division of the American Army which thrust the Germans behind their first line and captured upwards of 1,000 prisoners, the ground regained in the river bend being consolidated and held by the American division. The battle continued for three days before the German {50} attack was brought to a standstill, and at 4.80 a.m. on July 18 a counter-attack by the French, American, and Italian forces changed the whole aspect of the campaign, and led to the final triumph of the Allies and to the downfall of the Central Powers.
{51}
THE ATTACK
"Surprise is at all times the assailant's strongest weapon."—"Field
Service Regulations," vol. ii. (1920).
The aim of every commander who possesses the power of manoeuvre is to seek out the enemy and destroy his organised forces. The Attack is the culminating point of all manoeuvres to this end, and every commander will endeavour to achieve his aim by a sudden and unexpected assault on a part of the enemy's defences.
The achievement of this aim is only possible when a commander has assembled a sufficient force for his purpose, and has obtained, by reconnaissance and by fighting, information as to the vulnerability of the hostile position. The commander will then endeavour to break the enemy's formation so suddenly as to disconcert all his plans; to retain a compact force with which to follow up the blow without giving the enemy a moment's breathing space; to drive a wedge into the heart of his disordered masses, forcing his wings asunder; and to pursue and annihilate the scattered forces of the enemy.
"Unless a decision is quickly obtained in the opening weeks of a modern campaign the opposing armies tend to become immobile, chiefly owing to the great power conferred on the defence by modern armaments. The armies will then be distributed in great depth, and the attackers are faced with the necessity of breaking through not one position only, but a series of positions, extending back to a depth of several miles" ("Infantry Training, 1921").
Penetration, followed by the sundering of the Franco-British Armies, was clearly the intention of the German {52} High Command in the Second Battle of the Somme, which opened on March 21, 1918. The German Armies had entrenched themselves after the First Battle of the Marne (September, 1914), and for 43 months had been confronted by the Allied Nations of Britain, France, and Belgium, reinforced at the close by Portuguese troops and by the National Army of the United States.