"Sir Maurice Hankey: "Control of these resources becomes a first-class war aim"\n\nDuring World War I (1914-18), strategists for all the major powers increasingly perceived oil as a key military asset, due to the adoption of oil-powered naval ships, new horseless army vehicles such as trucks and tanks, and even military airplanes. Use of oil during the war increased so rapidly that a severe shortage developed in 1917-18."