Under the command of General Pershing, the American Expeditionary Forces first arrived in France in mid-1917. Wilson and Pershing rejected the British and French proposal that American soldiers integrate into existing Allied units, giving the United States more freedom of action but requiring for the creation of new organizations and supply chains. Russia exited the war after signing the Treaty of Brest-Litovsk in March 1918, allowing Germany to shift soldiers from the Eastern Front of the war. Hoping to break Allied lines before American soldiers could arrive in full force, the Germans launched the Spring Offensive on the Western Front. Both sides suffered hundreds of thousands of casualties as the Germans forced back the British and French, but Germany was unable to capture the French capital of Paris. There were only 175,000 American soldiers in Europe at the end of 1917, but by mid-1918 10,000 Americans were arriving in Europe per day. With American forces having joined in the fight, the Allies defeated Germany in the Battle of Belleau Wood and the Battle of Château-Thierry. Beginning in August, the Allies launched the Hundred Days Offensive, pushing back the exhausted German army. Meanwhile, French and British leaders convinced Wilson to send a few thousand American soldiers to join the Allied intervention in Russia, which was in the midst of a civil war between the Communist Bolsheviks and the White movement.