The Japanese confidence in their ability to win a quick victory meant that they neglected Pearl Harbor's navy repair yards, oil tank farms, submarine base, and old headquarters building. All of these targets were omitted from Genda's list, yet they proved more important than any battleship to the American war effort in the Pacific. The survival of the repair shops and fuel depots allowed Pearl Harbor to maintain logistical support to the U.S. Navy's operations, such as the Doolittle Raid and the Battles of Coral Sea and Midway. It was submarines that immobilized the Imperial Japanese Navy's heavy ships and brought Japan's economy to a virtual standstill by crippling the importation of oil and raw materials: by the end of 1942, the amount of raw materials brought in was cut in half, "to a disastrous ten million tons", while oil "was almost completely stopped". Lastly, the basement of the Old Administration Building was the home of the cryptanalytic unit which contributed significantly to the Midway ambush and the Submarine Force's success.