Naval history of World War II 4–7, 1942, the United States Navy decisively defeated a Japanese naval force that had sought to lure the U.S. carrier fleet into a trap at Midway Atoll. The Japanese fleet lost four aircraft carriers to the U.S. Navy's one American carrier and a destroyer. After Midway, and the exhausting attrition of the Solomon Islands campaign, Japan's shipbuilding and pilot training programs were unable to keep pace in replacing their losses while the U.S. steadily increased its output in both areas. Military historian John Keegan called the Battle of Midway "the most stunning and decisive blow in the history of naval
Japanese aircraft carrier Shōkaku was added at the bow and stern and 10 single mounts were added before the Battle of the Philippine Sea in June 1944. "Shōkaku" and "Zuikaku" formed the Japanese 5th Carrier Division, embarking their aircraft shortly before the Pearl Harbor attack. Each carrier's aircraft complement consisted of 15 Mitsubishi A6M2 "Zero" fighters, 27 Aichi D3A1 "Val" dive bombers, and 27 Nakajima B5N1 or −2 "Kate" torpedo bombers. "Shōkaku" and "Zuikaku" joined the "Kido Butai" ("Mobile Unit/Force", the Combined Fleet's main carrier battle group) and participated in Japan's early wartime naval offensives, including Pearl Harbor and the attack on Rabaul in