Hence at the beginning of 1918 they outnumbered their opponents in the west and they were determined to attack for victory. Kuhl's proposal for an attack on the vital British railroads in Flanders was accepted, but while waiting for the ground to dry there, in March 1918 they smashed through the southern British front near Cambrai, using troops from the two armies on the southern flank of Army Group Rupprecht. Their success was so overwhelming that they extended the attack, but failed to separate the French and British armies and depleted resources intended for Flanders. When they did attack there they smashed through the British and Portuguese lines, but were stopped short of their strategic goal. To drain allied reserves from Flanders, the Germans shifted direction to hit the French in the south, once again shredding through their opponents lines, but failing to smash their will to resist. The Germans were about to attack again in Flanders so Kuhl, Rupprecht and their artillery commanders were meeting with Ludendorff to finalize the plans for the opening barrage when they learned by telephone that a joint French and American assault had shredded the German flank in the south. As Rupprecht wrote in his diary "no doubt we have passed the high point of this year's achievements". They all realized that they lacked the resources for continuing their attacks, so they went on the defensive.