world war 1

1917–1918

In the trenches: Royal Irish Rifles in a communications trench on the first day on the Somme, 1 July 1916Events of 1917 proved decisive in ending the war, although their effects were not fully felt until 1918. The British naval blockade began to have a serious impact on Germany. In response, in February 1917, the German General Staff convinced Chancellor Theobald von Bethmann Hollweg to declare unrestricted submarine warfare, with the goal of starving Britain out of the war. Tonnage sunk rose above 500,000 tons per month from February to July. It peaked at 860,000 tons in April. After July, the reintroduced convoy system became extremely effective in neutralizing the U-boat threat. Britain was safe from starvation and German industrial output fell.

The victory of Austria-Hungary and Germany at the Battle of Caporetto led the Allied at the Rapallo Conference to form the Supreme Allied Council to coordinate planning. Previously, British and French armies had operated under separate commands.

In December, the Central Powers signed an armistice with Russia. This released troops for use in the west. Ironically, German troop transfers could have been greater if their territorial acquisitions had not been so dramatic. With German reinforcements and new American troops pouring in, the final outcome was to be decided on the Western front. The Central Powers knew that they could not win a protracted war, but they held high hopes for a quick offensive. Furthermore, the leaders of the Central Powers and the Allies became increasingly fearful of social unrest and revolution in Europe. Thus, both sides urgently sought a decisive victory.[40]