On 21 March 1918 Germany launched a full scale Spring Offensive against the British and French lines, hoping for victory on the battlefield before United States troops arrived in large numbers. The Allied armies fell back 40 miles in confusion, and facing defeat London realized it needed more troops to fight a mobile war. Lloyd George found half a million soldiers and rushed them to France, asked American President Woodrow Wilson for immediate help, and agreed to the appointment of the French Marshal Foch as commander in chief on the Western Front, so that Allied forces could be coordinated to handle the German offensive.[23]