In 1915, Hale joined the American Field Service (AFS) as an ambulance driver. He served in that role with the French Army in Alsace-Lorraine during World War I from February 1915 to May 1916. Hale was one of the first two AFS volunteers to receive the Croix de guerre for his volunteerism. After his return from France, Hale joined the U.S. Army to serve in the Mexican Expedition. The campaign during the Border War fought the paramilitary forces of Pancho Villa. In 1917, he enlisted as a private with the Army Signal Corps.