Lacking strategic railways to match those of Germany, France evolved an effective substitute in the modern system of automobile transportation. When von Kluck swung aside from Paris in his first great rush, Gallieni sent out from Paris an army in taxicabs that struck the exposed flank and went far toward winning the first battle of the Marne. It was the truck transportation system of the French along the famous "Sacred Road" back of the battle line at Verdun that kept inviolate the motto of the heroic town, "They Shall Not Pass." Motor trucks that brought American reserves in a khaki flood won the second battle of the Marne. It was automobile transportation that enabled Haig to send the British Canadians and Australians in full cry after the retreating Germans when the backbone of the German resistance was broken before Lens, Cambrai, and Ostend.
America's railway transportation system in France was one of the marvels of the war. Stretching from the sector of seacoast set apart for America by the French Government, it radiated far into the interior, delivering men, munitions and food in a steady stream. American engineers worked with their brothers-in-arms with the Allies to construct an inter-weaving system of wide-gauge and narrow-gauge roads that served to victual and munition the entire front and further serve to deliver at top speed whole army corps. It was this network of strategic railways that enabled the French to send an avalanche clad in horizon-blue to the relief of Amiens when Hindenburg made his final tremendous effort of 1918.
In its essentials, military effort in the great conflict may be roughly
divided into
Open warfare,
Trench warfare,
Crater warfare.
The first battle of the Marne was almost wholly open warfare; so also were the battles of the Masurian Lakes, Allenstein, and Dunajec in the eastern theater of war, and most of the warfare on the Italian front between the Piave River and Gorizia.
In this variety of battle, airplanes and observation balloons play a prominent part. Once the enemy is driven out of its trenches, the message is flashed by wireless to the artillery and slaughter at long range begins. If there have been no intrenchments, as was the case in the first battle of the Marne, massed artillery send a plunging fire into the columns moving in open order and prepare the way for machine gunners and infantry to finish the rout.
In previous wars, cavalry played a heroic role in open warfare; only rarely has it been possible to use cavalry in the Great War. The Germans sent a screen of Uhlans before its advancing hordes into Belgium and Northern France in 1914. The Uhlans also were in the van in the Russian invasion, but with these exceptions, German cavalry was a negligible factor.
British and French cavalry were active in pursuit of the fleeing Teutons when the Hindenburg line was smashed in September of 1918. Outside of that brief episode, the cavalry did comparatively nothing so far as the Allies were concerned. It was the practice on both sides to dismount cavalry and convert it into some form of trench service. Trench mortar companies, bombing squads, and other specialty groups were organized from among the cavalrymen. Of course the fighting in the open stretches of Mesopotamia, South Africa and Russia involved the use of great bodies of cavalry. The trend of modern warfare, however, is to equip the cavalryman with grenades and bayonets, in addition to his ordinary gear, and to make of him practically a mounted infantryman.
Trench warfare occupied most of the time and made nine-tenths of the discomforts of the soldiers of both armies. If proof of the adaptive capacity of the human animal were needed, it is afforded by the manner in which the men burrowed in vermin-infested earth and lived there under conditions of Arctic cold, frequently enduring long deprivations of food, fuel, and suitable clothing. During the early stages of the war, before men became accustomed to the rigors of the trenches, many thousands died as a direct result of the exposure. Many thousand of others were incapacitated for life by "trench feet," a group of maladies covering the consequences of exposure to cold and water which in those early days flowed in rivulets through most of the trenches. The trenches at Gallipoli had their own special brand of maladies. Heatstroke and a malarial infection were among these disabling agencies. Trench fever, a malady beginning with a headache and sometimes ending in partial paralysis and death, was another common factor in the mortality records.
But in spite of all these and other discomforts, in spite of the disgusting vermin that crawled upon the men both in winter and in summer, both sides mastered the trenches and in the end learned to live in them with some degree of comfort.
At first the trenches were comparatively straight, shallow affairs; then as the artillery searched them out, as the machine gunners learned the art of looping their fire so that the bullets would drop into the hiding places of the enemy, the trench systems gradually became more scientifically involved. After the Germans had been beaten at the Marne and had retired to their prepared positions along the Aisne, there commenced a series of flanking attempts by one side and the other which speedily resolved itself into the famous "race to the sea." This was a competition between the opposing armies in rapid trench digging. The effort on either side was made to prevent the enemy from executing a flank movement. In an amazingly short time the opposing trenches extended from the Belgian coast to the Swiss border, making further outflanking attempts impossible of achievement.