During World War I, the Ottomans sided with Germany and the Central Powers. In the Mesopotamian campaign against the Central Powers, British forces invaded the country and initially suffered a major defeat at the hands of the Turkish army during the Siege of Kut (1915–1916). However, subsequent to this the British began to gain the upper hand, and were further aided by the support of local Arabs and Assyrians. In 1916, the British and French made a plan for the post-war division of Western Asia under the Sykes-Picot Agreement. British forces regrouped and captured Baghdad in 1917, and defeated the Ottomans. An armistice was signed in 1918. The British lost 92,000 soldiers in the Mesopotamian campaign. Ottoman losses are unknown but the British captured a total of 45,000 prisoners of war. By the end of 1918, the British had deployed 410,000 men in the area, of which 112,000 were combat troops.