For future operations it was depending upon more than the elaborate fortifications of that line. Every hundred yards from the foot of the whale-back to the summit was in its favor in resisting attack. Higher ground leads to still higher ground, not in a regular system of ridges but in a terrain where nature cunningly serves the soldier. Nowhere might the defense invite the attack into salients with a better confidence, or feel more certain of the success of his counter-attacks. All roads, and all valleys where roads might be built, were under observation. Heights looked across to heights on either side of the two river troughs, heights of every shape from sharp ridges and rounded hills to peaked summits crowned by woods. Tongues of woods ran across valleys. Patches of woods covered ravines and gullies where machine-gunners would have ideal cover and command of ground. Reverse slopes formed walls for the protection of the artillery. The attack must fight blindly; the defense could fight with eyes open. Had the Allies attempted an offensive in the Meuse-Argonne sector in the first four years of the war, the long and extensive preparations then regarded as requisite for an ambitious effort against first-line fortifications would have warned the Germans in time to make full use of their positions in counter-preparations. All the advantage of railroads and highways were with them in concentrating men and material. It might not be a long distance in miles from the Argonne line to the Lille-Metz railway or to the Briey iron-fields, but it was a long distance if you were to travel it with an army and its impedimenta against the German Army in its prime. When attrition was in his favor in the early period, the German might well have preferred that the Allied offensive of Champagne, or Loos, or the Somme, or Passchendaele, should have been attempted here: thus leaving open to him, after he had inflicted a bloody repulse in this sector, the better ground in the north for a telling counter-offensive. Thus an Allied effort toward Mézières, Sedan, and Briey would have been madness until the propitious moment came. Had it really come now? Anyone who was familiar with the history of warfare on the Western Front might ask the question thoughtfully. Bear in mind that we had not yet taken Saint-Mihiel and were not yet certain of our success there; and that from Soissons to Switzerland the old German line was intact. North of Soissons we had broken into it at only a few points. In the event that they had had to make a strategic withdrawal, the Germans had always followed the tactical system of a full recoil to strong chosen positions, where they resisted with sudden and terrific violence and held stubbornly and thriftily until they began one of their powerful counter-thrusts.