Dinter took part in the First World War as an Oberleutnant in an Alsatian Infantry Regiment Number 136, and was quickly promoted to captain of the reserve and awarded the Iron Cross, Second Class. In 1915, he fell ill with cholera, and in 1916 he spent a great deal of time in field hospitals having suffered serious wounds, after which he had to be discharged from the military. During his stay in the field hospitals, Dinter became familiar with German nationalist and mystic Houston Stewart Chamberlain's writings and quickly became a follower of the völkisch movement.