WI : The 14 July 1918 Mont-sans-Nom commando raid failed and didn’t give access to Friedensturm maps

[Meordal]

In OTL

During Second Battle of the Marne, the German failure to break through, or to destroy the Allied armies in the field, allowed Ferdinand Foch, the Allied Supreme Commander, to proceed with the planned major counteroffensive on 18 July; 24 French divisions, including the American 92nd and 93rd Infantry Divisions under French command, joined by other Allied troops, including eight large American divisions under American command and 350 tanks attacked the recently formed German salient.

The Allied preparation was very important in countering the German offensive. It was believed that the Allies had the complete picture of the German offensive in terms of intentions and capabilities. The Allies knew the key points of the German plan down to the minute.

Le coup de main du Mont-sans-Nom was a commando operation of the First World War conducted on July 14, 1918 by the detachment of Lieutenant Darius Balestié and in particular by the Free Corps of Sergeant Joseph Darnand. It provided important informations on artillery and maps on the impending German offensive that would later be called the "Fourth Battle of Champagne" ("Friedensturm" for the Germans) whose failure would mark a decisive victory for the Allies.

Informed since July 7 that he would be attacked at any moment, Gouraud set a second line of defence two kilometres behind his positions and sought field information by ordering the commando raid of Mont-sans-Nom. It was a success and prisoners revealed that a massive seven-day long artillery preparation with mustard gas shells was scheduled to begin at midnight ten. Half an hour before German artillery preparation, the French launched a counter-batterie fire that disabled the artillery units preparing for the assault and shook the infantry units.

Nevertheless the German assault continued, as scheduled, on July 15, 1918, at 4:45 a.m., accompanied by a rolling barrage of conventional artillery. The first French trenches were captured despite heavy machine gun fire, but three quarters of them were unoccupied, as their defenders had withdrawn as planned (Petain directive numéro 4).

The Germans attacked the main line at 08:30 the following morning, an hour after their schedule. They were stopped by accurate fire by the bulk of the French artillery. This barrage forced the German troops to take shelter in the French evacuated shelters that were allegedly trapped with mustard gas. Accompanying tanks exploded on explosive cords hidden in their paths. They tried again at noon, but failed.

Arriving in front of the intact and reinforced second positions, the assault battalions could not force the lines without the support of heavy artillery. The exploitation troops that followed the breakthrough, were decimated by artillery grapeshots.

On July 16, after a final German assault, Gouraud's troops returned to the abandoned positions. It convinced the German commanders that they could not prevail.

What if this commando raid was either delayed or a failure, providing no maps or informations on the impending attack?

 

[Vornado]

In all honesty this probably doesn't make much of a difference. Unless the French army collapsed the end of the war was clear at this point.

 

[Dwergar]

With allies expending most of their forces in stopping german offensive, their own offensive proves inconclusive, and the war continues on to 1919, Entente amassing even more shells and weaponry to break through german lines.
With front broken, second reich collapses, and in ravaged postwar Germany socialist and communist forces take reigns.
Ultimately, WWII starts sometime in the forties, where revanchist and ideologically allied Germany and USSR decisively defeat continental opposition and enter an attritional phase against Britain and her dominions in the skies above the islands, aiming to to defeat them before american government enters the war even though they're providing low-key support to the Albion.

 

[Catspoke]

With allies expending most of their forces in stopping german offensive, their own offensive proves inconclusive, and the war continues on to 1919, Entente amassing even more shells and weaponry to break through german lines.
With front broken, second reich collapses, and in ravaged postwar Germany socialist and communist forces take reigns.
Ultimately, WWII starts sometime in the forties, where revanchist and ideologically allied Germany and USSR decisively defeat continental opposition and enter an attritional phase against Britain and her dominions in the skies above the islands, aiming to to defeat them before american government enters the war even though they're providing low-key support to the Albion.

So this is the best case German scenario, The German achieve surprise and actually encircle and take Reims, which sorts of obfuscates the turning of the tide, helps morale a bit.
Even though Austria, Bulgaria and the Ottomans all drop out as OTL. The Germans in this TL, do not do a last naval sortie, the Germans hold on in November, and secure reachable points in Austria, the Brenner pass, Salzburg, the Skoda works, and start evacuating from the furthest reaches of Russia (behind the Dnieper). Germany withdraws to their frontier in the west.

In May 1919, the Allies launch an attack on the western front, (Italy is disinterested into attacking into southern Germany by this point, more worried about the South Slavs), no real attack occurs on Germany's southern frontier. but the attack on Germany's western frontier is a real meat grinder, the Allies materiel superiority breaks Germany within a couple months.

As per your post, socialist and communist forces take reigns, right wing groups more discredited and weaker (maybe Hitler dies in the 1919 battles).