 Complete the following phrase:  In the First World War, German plans to capture Paris quickly in the autumn of 1914 failed, and the war on the Western Front became a stalemate. The Allied naval blockade caused severe shortages of food. However, Imperial Germany had success on the Eastern Front; it occupied a large amount of territory to its east following the Treaty of Brest-Litovsk. The German declaration of unrestricted submarine warfare in early 1917 contributed to bringing the United States into the war. In October 1918, after the failed Spring Offensive, the German armies were in retreat, allies Austria-Hungary and the Ottoman Empire had collapsed, and Bulgaria had surrendered. The empire collapsed in the 