 From August 1917 to August 1919, Dawes served in France during World War I as chairman of the general purchasing board for the American Expeditionary Forces (AEF), as a member representing the AEF on the Military Board of Allied Supply, and, after the war, as a member of the Liquidation Commission of the United States War Department.He was decorated with the Distinguished Service Medal and the French Croix de Guerre in recognition of his service.He returned to the United States on board the SS "Leviathan" in August 1919.