Ludendorff gave him the opportunity he wanted. Ludendorff, on the other hand, with the pick of his troops 'pocketed' in the great Marne salient, was forced to make another forward move or withdraw them. He made one more attempt on Rheims, three divisions being ordered on 18th June to take it at all costs; but the whole attack was an expensive failure. For the rest of the month, when the weather broke, and during the first half of July, Ludendorff left most of the fighting to the Allies while he prepared for one last herculean effort to burst through their line. On 28th June Foch felt his way towards his counter-stroke by a preliminary advance between Villers-Cotterets and the Aisne, when he won back over a mile of useful territory and took over 1000 prisoners. On 4th July further minor victories were recorded along both the French and British fronts, the British success being at Hamel, where American units celebrated Independence Day by helping the Australians to recover that fiercely-contested stronghold, with 1500 prisoners.
On 15th July Ludendorff launched his final effort on a 50-mile front on each side of Rheims. This time the Allies were warned of its direction in time. On the left, where immediate success was vital to the whole plan, the attack was flung into disorder at the very beginning by a deluge of shells from Gouraud's guns before even the German bombardment started; and when, this over, the attacking divisions of von Einem and von Mudra advanced, they found that Gouraud's army, save for volunteer garrisons in concrete forts, had returned undamaged to its main battle positions, to reach which they had to face a concentrated fire that tore their ranks to pieces. Some 50,000 German troops were admitted to have fallen that day before Gouraud's army. With the failure of the advance in Champagne the German attack on the right, where Italian as well as British and American troops were now fighting side by side with the French, was unavailing, though the line south-west of Rheims was pressed back some 3 or 4 miles, and eight divisions under von Böhn succeeded by 17th July in crossing the Marne at a number of points between Fossoy and Dormans.
Foch's Counter-stroke
They were only allowed to remain south of the Marne long enough for Foch to convert these river crossings into a death-trap. For Foch had now decided that the moment had come when the Germans, exhausted by their advance, were least in a condition to resist a counter-stroke aimed at their flank. The flank which Foch selected for attack was that on the western side of the salient created, from its most northerly point on the Aisne near Soissons, to its southern extremity, Château-Thierry on the Marne, where the symptoms of the exhaustion of the
German momentum had been furnished by the ability of American and other contingents to resist further advance. In the earlier half of July a ceaseless stream of men and guns had flowed up from the French side to take cover in the forest of Villers-Cotterets on their flank, in preparation for the blow to come; and by 18th July two French armies were assembled along the 27-mile flank, that of General Mangin aligned between the Aisne and the Ourcq, which bisected the salient, and that of General Degoutte from the Ourcq to the Marne. Mangin's army contained some of the finest French shock divisions as well as two famous British ones, the 34th and the 15th, and a number of keen American troops. Degoutte's army had the more awkward task, judged by the country over which it had to travel, but Foch's plan here, as elsewhere, was to put his best fighting material where it would pierce farthest, and hold the enemy elsewhere. By the same token the army of General Berthelot, with two other supporting British divisions, was entrusted with the task on the other side of the salient, from Rheims to Épernay, not of thrusting at the Germans but of holding them hard.
Mangin's army was ordered to strike with all its force. It was equipped with new and speedier 'whippet' tanks, and its immediate onset was masked by the accident of a July thunderstorm on the eve of the fighting. On the morning of 18th July it went forward with nothing but a barrage, but with the effect of a thunderbolt, and its average advance on that day was 5 miles, with Fontenoy and the plateau of Pernay on the Aisne firmly secured. Degoutte's army went forward for 2 miles over difficult country. A blow of immense significance had been struck along the whole length of the salient's vulnerable side. Next day Mangin's movement continued; he tightened his hold on the Aisne and swung his right wing farther along the Ourcq so as to bring the whole line of the one good north-and-south road in the salient under the fire of his guns, and thus to hamper the German movements terribly. That alone would have forced the enemy to begin a retreat from the Marne, while it might yet be possible. Meanwhile Degoutte was advancing also, and was forcing the Germans away from the neighbourhood of Château-Thierry. The German commander, von Böhn, was not slow to recognize the implications of the situation into which Foch had forced him, and gave orders to recross the Marne. He was in time, but his retreating troops were roughly handled at the crossings, and despite all his attempts to hold up the attack on his western flank by counter-attack, the pressure of Mangin and Degoutte, added to that of de Mitry's army, which was now following him back over the Marne, became every hour more dangerous. By 20th July not only was the Marne itself in process of being abandoned by von Böhn but Château-Thierry had fallen. Degoutte's army was 3 miles north of it. De Mitry's divisions had secured ample crossings for future movement and Berthelot's mixed forces of French, British, and Italians had begun a disconcerting attack on the eastern side of the salient. In three days the Germans lost 20,000 prisoners, and, what was more significant, 450 guns. The first riposte of the French Generalissimo had been delivered. It was to be followed in unending succession by others.
The German Commander-in-Chief had to gain time. It was no easy thing to withdraw his 600,000 men crowded between the Aisne and the Marne, but he was obliged to support them lest the salient should collapse too suddenly. He aimed a counter-stroke at Gouraud's army east of Rheims, but the blow spent itself in the air, and Foch replied by setting in motion the army of General Debeney, where it stood opposite to that of General von Hutier, between Montdidier and Noyon. But he had not yet gathered the full fruits of the strength of his positional assault between the Aisne and the Marne, and did not in the least allow pressure here to relax. Mangin seized Oulchy-le-Château on the Ourcq (25th July); and on 26th July Gouraud, on the other side of Rheims, recovered the ground he had ceded under the German pressure. By Sunday (28th July) the Allied attack in the Aisne-Marne salient had swept convergingly on to the line of the Ourcq, and with that achievement the most important episode in the opening of Foch's campaign was consummated. Soissons fell to Mangin on 1st and 2nd Aug., a signal that the work was done, and Foch was now free to prosecute his larger plan of delivering successive blows at points where they would disperse and use up the German reinforcements most effectively.
The Allies' Victorious Offensive, 1918