In July, 1918, the western battle line, running from the North Sea to Switzerland, was, in general, a huge curve bending into France. Germany had been working on interior lines on this western front--that is, as her forces were needed to defend or to attack, she moved them from place to place on the inside of the circle. The Allies were obliged to work on the outside of the circle and were therefore at a considerable disadvantage. Then, too, the Germans had the initiative, that is, they could determine when and where to attack, while the Allies in 1918, up to July 18, were having all they could attend to in defending themselves and preventing a serious break in their lines. With July 18, 1918, all this was changed. The Allied forces were now under the direction of a single commander, Marshal Foch, one of the great military geniuses of all time. His plan was to strike at a weakened point; then, when the Germans had rushed reinforcements to ward off the danger, to strike at some other point in the line and thus use up the German reserves; and to give the German commanders no time to prepare an offensive on a large scale. The German by nature seems to think that size determines victory. The big things seem to him the things that are effective and that win. So his offensives were planned on a great scale and required months of preparation; and after one offensive had been stopped, he required more months of comparative rest to plan and prepare another. The French nature is different; it is subtle, deft, and skillful, and by repeated strokes of less force, often accomplishes what the German fails to do with one mighty blow. In riveting the plates on a ship, or in joining the framework of a steel skyscraper, a riveting machine is used which, by very rapidly repeated blows, does the work quickly and well. Somewhat in this way did Marshal Foch strike the German line, now in this spot, now in that, capturing or putting out of action large numbers of German troops, outflanking first one strategic point and then another. As a consequence, the German line was obliged to draw back and back to prevent the Allies from breaking through and attacking the German supply trains coming up in the rear with food and munitions. West of Verdun the Germans had come into Belgium and France along the line of the Meuse through Liége and Namur, and across Luxemburg by the main railway through Sedan. Could either of these great lines of communication be captured, the Germans would be unable to withdraw to their own territory without terrible losses, if at all; for between their armies and Germany lay the great forest region of Ardennes with but few roads. Two millions of men could not retreat through this region without leaving guns and munitions behind and their retreat becoming a rout.