In August 1941, Mountbatten was appointed captain of the aircraft carrier which lay in Norfolk, Virginia, for repairs following action at Malta in January. During this period of relative inactivity, he paid a flying visit to Pearl Harbor, three months before the Japanese attack on it. Mountbatten, appalled at the US naval base's lack of preparedness, drawing on Japan's history of launching wars with surprise attacks as well as the successful British surprise attack at the Battle of Taranto which had effectively knocked Italy's fleet out of the war, and the sheer effectiveness of aircraft against warships, accurately predicted that the US would enter the war after a Japanese surprise attack on Pearl Harbor.