The German plans were, as usual, based upon their suppositions as to the plans and preparations of the Allies in France. Hindenburg still seemed in 1917 to cling to his original plan of holding the lines in the west, while all German foes in the east were beaten and victory then made final. Though the Russian army had been considered beaten in 1915, had been again demolished in 1916, its continued existence alone compelled the Germans to retain a strong force of men on the eastern front. They therefore schemed in the winter of 1917 to remove Russia permanently from the conflict and to conquer her for the present and for the future. They precipitated the Russian Revolution in March, thought  they controlled the situation and believed when the Revolution came that it was their own work. It did therefore form a part of the plans of the German High Command.")?> to put Russia definitely out of the war and to release the German armies on the east front. They would then throw large forces against Italy in the fall of the year, at the season most favorable for the campaigning in the south, and treat her as they had treated Poland and Rumania. They could then end the war in 1918.

Meanwhile Von Tirpitz was to attempt to bring England to her knees by means of unrestricted submarine warfare. For two years now the submarine had sunk British shipping where it could, but, despite their general lack of humanity, the Germans had observed some of the rules and practices of the past. They now announced to the world that from February 1, 1917, they would sink any and all ships that the submarines might meet. They declared a danger zone around the British Isles and the French coast within which no ship, however neutral, should be safe. They thus rescinded all the promises they had made to the United States and other nations of warning to vessels in order to allow the crew and passengers to escape. The new order was "Sink without trace": the ship must disappear—there must be no survivors to tell the tale of how she was lost. They promised themselves that England and France would be put to such straits by this unrestricted warfare that the factories would be unable to get the raw materials necessary to continue the war. Food would give out, especially in England, and the British would be compelled to sue for peace.

Meantime while Russia was being successfully revolutionized, while the submarine was bringing Great Britain to terms, the lines should be held in France with the least possible effort. They should maintain the defensive as cheaply as possible. Hindenburg knew well that the British and French had made extraordinary preparations throughout the fall and winter for an assault upon the German lines. Special railroads had been built all along the front to make easy the movement of troops, of ammunition, and of food so that men could be massed readily at any point, transferred elsewhere with rapidity, fed there, and supplied with ammunition.

In February and March, therefore, to render all these preparations useless, Hindenburg withdrew the German lines to the famous Hindenburg line, a new line of defense elaborately prepared, miles enough in the rear of the old line to prevent any assault upon it by the British and French from the positions which they had prepared so carefully during the winter. Moreover, the Germans destroyed every living thing, every building, every tree, every possible shelter in the entire zone, which they thus abandoned; it was laid waste with a thoroughness which only Germans can attain. The Allies must therefore attack them over a waste ground where everything would impede their progress to the maximum and where there would be nothing to aid them.

The results were not exactly what the Germans had anticipated. The United States promptly entered the war on April 6, 1917, and undertook with equal promptitude an extent of preparations which paralyzed the German statesmen and generals. Conscription was voted almost immediately and an army of millions was put at once into training. The United States government took over factories and railroads and began to build ships to transport the new troops to France. Indeed, we began to build from the bottom an army of five millions of men, with everything necessary to place them on the fighting line in France and keep them there indefinitely. The example of the United States was followed by declarations of war from a crowd of hitherto neutral states in South America and in Asia.

In a measure the new submarine menace was met by the seizure of German ships interned in American and neutral harbors. They were promptly repaired, despite the fact that the Germans had intended to injure them so that they could not be put into service for some years. In June, Greece joined the Allies, and the obstacle to an assault upon the Austrian rear, which had bothered the Allies for three years, was removed.

In April the British delivered a great assault on the German lines around the city of Arras, to the north of the new Hindenburg line in a position not affected by the German retirement. Although some territory was won, the battle failed to break through the German trenches, and in July the British began a determined effort, which was continued until December, to break through the German lines along the coast so as to reach the submarine base at Ostend and Zeebrugge. Not only did they feel that if they could capture the coast they might lessen the power of the which was already committing great inroads upon the world's shipping, but they might also turn the German right and compel the withdrawal of the whole line over a considerable area of territory. But the attempt failed. In the center an attack was launched on November 20, at Cambrai, known as the battle of the tanks, which did gain a larger amount of territory than the Allies had up to that time won; but some of it was lost again and in general the success failed to produce any effect upon the fundamental strength of the German position.

Meanwhile, the Italians had begun on the Isonzo in May a great assault against the Austrian army, intrenched around Trieste. The object was twofold; partly to put pressure upon the Germans on two fronts at the same time, and partly to win the Austrian territory occupied by people of Italian blood, which the Italians were determined to add to Italy when the war should end. They felt that there was small chance of its cession to Italy unless they should capture it during the war. They therefore made this determined attempt throughout the summer to capture Trieste. In October, the Germans and the Austrians delivered a well-timed and well-planned blow against the Italian army along the Isonzo. They broke the left of the Italian army before Trieste and won through the mountains into the valley below.

The entire Italian position was at once flanked and the great bulk of the army in great danger of being cut off and captured. To escape, it was necessary for the army almost to run; to abandon its artillery and baggage; and to make its way back at breakneck speed to some new front. Finally, in November, after a magnificent retreat, a new front was established on the Piave. British and French aid had been promised and had arrived. The French and British had marched on foot from France, had crossed the Alps, and joined the Italians. A furious attack was delivered by the Austrians in November and December, but the line on the Piave was successfully held.

Yet the net result of the year 1917 was extremely discouraging for the Allies. Russia was unalterably out of the war; all possible help from her army had evaporated. Italy was in the gravest danger thinkable. The submarine had been successful in sinking an amount of shipping which the Allies had not believed possible although it was far less than the Germans had thought probable. It had not prevented the supply of the British and French armies in France nor interfered for a day or an hour with the stream of ammunition, but, if the loss should continue at that rate, there was no knowing when the submarine would make itself felt on the battle line. England was building ships at furious speed; so was the United States; but the submarine was sinking them immensely faster than they could be built.

Meanwhile the Allies had failed to gain anything of moment in France. They had supposed that a simultaneous offensive on more than one front would expose the Germans and Austrians to certain defeat on some point. But instead the Germans had successfully held the lines in France and had won victory after victory elsewhere. The outlook was black indeed, for, although the United States had entered the war and had begun preparations of extraordinary magnitude, the American army could not in the nature of things take the field in great force for some months to come and perhaps for a year or more. The year 1918 every one foresaw would be the critical period of the war.