Allied Intervention in Russia.—At last the Allied nations and the United States decided that it was time to undertake military intervention in Russia. This was carried out in two places. Bodies of American and Japanese troops were landed on the east coast of Siberia to coöperate with the Czecho-Slovaks. The latter, thus reënforced, changed their plans for leaving Russia and decided to fight for the Allied cause where they were. They were encouraged by the fact that they were recognized by the Allies and by the United States as an independent nation.

Another small Allied army was landed on the north coast of Russia and marched south against the Bolsheviki. Large parts of Russia north and east of Moscow declared themselves free of Bolshevik rule. It was the hope of the Allies that that rule—now marked by pillage, murder, and famine—would shortly be overthrown and that a new Russia would rise and take its place among the democracies of the world.

The Western Front.—Early in 1918, after the failure of the German peace offensive in the west, rumors came from Germany of preparations for a great military drive on the western front. The "iron fist" and the "shining sword" were to break in the doors of those who opposed a German-made peace. There were good reasons for such an attack in the spring of 1918. Germany had withdrawn many troops from the east, where they were no longer needed to check the Russians. Further, although a few American troops had reached France, it was thought that not many could be sent over before the fall of 1918, and the full weight of America's force could not be exerted before the summer of 1919. It was to Germany's interest to crush France and England before the power of the American nation was thrown into the struggle against her.

Germany's New Plan of Attack.—The German military leaders therefore determined to stake everything upon one grand offensive on the western front while their own force was numerically superior to that of the Allies. Their expectation of victory in what they proudly called the "Kaiser's battle," was based not only upon the possession of greater numbers, but also upon the introduction of new methods of fighting which would overcome the old trench warfare. The new methods comprised three principal features.

In the first place, much greater use was made of the element of surprise. Large masses of men were brought up near the front by night marches, and in daytime were hidden from airplane observation by smoke screens, camouflage of various kinds, and by the shelter of woodlands. In this way any portion of the opposing trench line could be subjected to a heavy, unexpected attack.

Secondly, the advance was prepared for by the use of big guns in enormous quantities and in new ways. The number of guns brought into use in this offensive far exceeded that put into the Verdun offensive of 1916, which had been looked upon as the extreme of possible concentration of artillery. The shell fire was now to be directed not only against the trenches, but also far to the rear of the Allied positions. This would break up roads, railways, and bridges for many miles behind the trenches and prevent the sending of reinforcements up to the front. Vast numbers of large shells containing poisonous "mustard" gas were collected. These were to be fired from heavy guns and made to explode far behind the Allied lines. By this means suffocation might be spread among the reserves, among motor drivers, and even among the army mules, and by deranging the transport service make it impossible to concentrate troops to withstand the German advance.

In the third place, "shock" troops composed of selected men from all divisions of the army, were to advance after the bombardment, in a series of "waves." When the first wave had reached the limit of its strength and endurance, it was to be followed up by a second mass of fresh troops, and this by a third, and so on until the Allies' defense was completely broken.

By their excess in numbers and by these newly devised methods of warfare the German leaders hoped to accomplish three things: (1) to separate the British army from the French army; (2) to seize the Channel ports and interrupt by submarines and big guns the transportation of men and supplies from England to France; and (3) to capture Paris and compel the French to withdraw from the war. Let us now see how and why the Germans failed to secure any one of these three objectives, and how the Allied forces resumed the offensive in the summer of 1918.

The German Advance.—Five great drives, conducted according to the newly devised methods of warfare, were launched by the Germans between March 21 and July 15, 1918. The first, continuing from March 21 to April 1, called the battle of Picardy, was directed at the point where the British army joined that of the French near the Somme River. There was at this time no unified command of all the Allied armies, and the blow fell unexpectedly upon the British and won much territory before French assistance could be brought up. Outnumbered three to one, the British fell back at the point of greatest retreat to a distance of thirty miles from their former line. But the extreme tenacity of the British and the arrival of French troops prevented the Germans from capturing the important city of Amiens (ah-myăn´), or reaching the main roads to Paris, or separating the British and French armies. Learning a needed lesson from this disaster, the Allied nations agreed to a unified military command, and appointed as commander-in-chief the French General Foch (fosh), who had distinguished himself in the first battle of the Marne in 1914 and elsewhere. Before this step had been taken General Pershing had offered his small army of 200,000 Americans to be used wherever needed by the French and the British.

The second German offensive began on April 9 and was again directed against the British, this time farther to the north, in Flanders, between the cities of Ypres and Arras. In ten days the Germans advanced to a maximum depth of ten miles on a front of thirty miles. But the British fought most desperately and the German losses were enormous. At last the advance was checked and the Channel ports were saved. "Germany on the march had encountered England at bay"—and had failed to destroy the heroic British army.