By early 1917, the Great War was looking like a powder keg that was about to explode in the faces of the British and French leaders from stalemate to disaster. The Germans were beating the Russians and the Tsar looked to be overthrown. Britain was on the verge of starvation, much of France's natural resources were in German hands, and the Germans free to launch new offensives with their best troops, the veterans of the East Front, against the west, when the inevitable Russian surrender comes.
America was not in the war, even with the German submarines sinking thousands of tons of American shipping.
The Germans considered the problem of the United States earnestly seeing as how it could lead the Germans from triumph to humiliation. One German politician, Arthur Zimmerman, proposed a war on the North American Continent between German-supported Mexico and the United States. The Kaiser rejected this proposal, saying that, despite the small standing military of the United States, an American mobilization would lead to a defeat of Mexico, and a full-scale war on Germany, in which none but the most ambitious German officers saw any hope of victory.
The war carried on with a formally neutral United States sending hundreds of thousands of tons of arms and ammunition to Britain, a German advance on the Eastern Front and a stalemate in the West. That is, until the Tsar was overthrown, and the world's first communist state tragically established. In December, 1917, an armistice between the new Red Russia and Germany was signed. After a month of negotiations, the Germans got their way, at the Treaty of Brest-Litovsk. The Germans seized Ukraine, Belorussia and the Baltic Provinces. The Western Allies braced for impact. Hundreds of thousands of the best German troops in the veteran Army Group Linsingen and Army Group Woyrsch were about to slam into France.
The Germans, however, were not as comfortable with another offensive in northwestern France, which they believed among the barbed wire, trenches and artillery of the allies would end in disaster. It was agreed among the German staff that the new troops must attack somewhere else.
The German leadership moved for an offensive to mirror the French Plan XVII, and strike through Alsace-Lorraine in overwhelming force. Then, they would use the freedom of the trenches and mobility to swing north, take Paris, and slam into the rear of the Allied Armies in Northern France. Army Group Linsingen would attack the rear of the right flank of the allies, while Army Group Woyrsch would move on the left and center, where the Allies were spread thinner, cut off and bypass Paris, then strike the Allied left flank from behind.
While the Allies moved their forces from Northern France and Belgium to contain this breakthrough, the massed forces of the Germans in the North would break through the now poorly defended trenches of the British, take the Channel Ports of Dunkirk and Calais, rush to take the remaining undermanned fortifications of the Allies, and begin slowly moving West on a broad front to press the allies in the center against the German forces in the south, forcing the surrender of the Allied center. From there, the Germans could have free reign in France, and move south to the city that had for nearly four years served as the center of the French government, Bordeaux.
The date for this new German offensive was set for March 12th, 1918. It was called the Hindenburg Plan.