Opinions have differed concerning Von Ditfurth's appraisal of the comparative values of Rheims Cathedral and the tombstone of a German grenadier, but even the champions of military necessity were glad to learn later that the cathedral still stood, though much damaged. There was military excuse for the bombardment of the city of Rheims. But the cathedral was by far the most conspicuous object in the Rheims landscape. It was optional with the Germans to spare it except for some casual shell that missed its aim. On the contrary they chose the great church as a special target, as evidenced by repeated damage to the cathedral and by the destruction of buildings all about it by shell fire. This was certainly not military necessity, though the city of Rheims had a place in the new strategical plan developed by Field Marshal von Heeringen upon the collapse of the drive on Paris, which was foiled by the battles of the Marne.
The second phase of the battle of the Aisne contained two factors. One, the simplest, was the maintenance of that line of defense against any force that could be brought up against it by the Allies. It meant the ability to hold strongly fortified positions against all odds. The history of the trenches that winter, of which more will be said later, reveals the extent to which the Germans succeeded, aided by the iron craft of the old Prussian fighter General von Zwehl.
The other factor depended on the vexed question of means of communication. There was no cross-country railway linking the eastern German wing to the western German wing. As has been previously remarked, all supplies and munitions had to come in a roundabout way. Verdun was a desired goal, but Field Marshal von Heeringen was wise enough to know that if the crown prince's effort against General Sarrail had failed, if the Third French Army had secured heavy reenforcement, and if it had been left unmolested for a week, the outer ring of defenses around Verdun would, by that time, have become so amazingly strengthened that direct or frontal attack would be impossible, while the flanking attack had failed. It was vain, therefore, at the present time, to hope that the establishment of the direct communication between Metz and Verdun might pass into the hands of the invaders.