 Following the Armistice, Cole was transferred to the Tank Corps of the American Expeditionary Forces and appointed an instructor at the tank school at Bourg.During his service with Tank Corps in World War I, he met and befriended George S. Patton.Following his return to the United States, he served with 3rd Cavalry until summer 1922, when he entered the Troop Officers' Course at Army Cavalry School at Fort Riley, Kansas and graduated one year later.