The communiqués of both sides were for once in agreement. The French said: "After having broken the German offensive on the Champagne and Rheims mountain fronts on the 15th, 16th, and 17th, the French troops, in conjunction with the American forces, attacked the German positions on the 18th, between the Aisne and the Marne on a front of forty-five kilometres [about twenty-eight miles]. We have made an important advance into the enemy lines, and have reached the plateau dominating Soissons ... more than twenty villages have been retaken by the admirable dash of the Franco-American troops.... South of the Ourcq our troops have gone beyond the general line of Marizy, Ste.-Genevieve, Hautvesnes, and Belleau."
The German communiqué said: "Between the Aisne and the Marne, the French attacked with strong forces and tanks, and captured some ground." Later in the same communiqué the conclusion was drawn: "The battle was decided in our favor."
On the second day, while the march under Soissons continued, and there were scattering gains on the Marne side, the number of Allied prisoners grew to 17,000, and the number of guns captured to 360. Nobody could tell, at this point, whether the crown prince's army was retreating voluntarily or involuntarily. In many places the Germans were taken by American soldiers from the peaceful pursuit of cutting wheat behind the lines. Some high officers were nabbed from their beds. On the other hand, the fact that the German rear-guard actions were chiefly with machine-guns seemed to indicate that they were moving their heavy pieces back in fair orderliness.
On the third day the Germans were thrown back over the Marne, and the crown prince, having sent an unavailing plea to Prince Rupprecht for new troops, suddenly showed fight with the crack Prussian guards.
These guards had their worst failure of the war when they met the Americans. It is difficult to prevent the statement from sounding offensively boastful. It is, none the less, true. The Germans, having decided that their retreat was wearing the look of utter rout, and that they must resist fiercely enough to stop it, risked a British break-through to the north by throwing in Ludendorf's prize soldiers above the Marne. And although the American total of prisoners around Soissons had risen to nearly 6,000, and though they did force back the Prussian guard, they did not make prisoners from their number. One American after another told, afterward, with a sort of reluctant admiration, that the Prussian guard had died where it stood. This fighting near the Ourcq, and fatally near the vitals of the encircled crown prince, was the most desperate of the second Marne battle.
On July 21 Château-Thierry was given up by the Germans, and the pursuing Allies, French and American, drove the enemy beyond the highroad to Soissons, and threatened the only highway of retreat, as well as the German stores. The supply-centre within the salient was Fère-en-Tardenois, and it was being raked by Allied guns from both sides of the salient.
The character of the fighting changed again, so that again it was impossible to make sure if Von Boehm intended to stand somewhere north of the Marne and put up a fight, or if he intended to make all speed back to a straight line between Soissons and Rheims. The resistance was by machine-gun, so that Americans, having their first big experience with the enemy, insisted that he had nothing but machine-guns to trust to. It is, of course, possible that the crown prince and Von Boehm knew no more than anybody else whether they were going to clear out, men and supplies, or whether they would stop again and fight face foremost.
On July 22 the German command answered the question at least partially. On a line well above the Marne, they brought the big guns into play, and poured in shock troops. Airplanes from the Allied lines discovered, however, that the Germans were burning towns and store-houses for many miles behind the line.
The pressure on the Germans was being brought from the south, where the Americans were six or seven miles above Château-Thierry, and from the west and north, where the Franco-American troops were flaying the exposed side.
The stiffened resistance and the German artillery slowed, but could not stop, the Allied advance. The eastern side of the salient, from the Marne to Rheims, bore some desperate blows, but did not give way. As the pincers closed in, at the top of the salient, the German command appeared to go back to its original plan of attacking Rheims from the south.