United States Navy (USN) Pearl Harbor ( December 7, 1941), which temporarily put a number of Pacific Fleet battleships out of action but left intact the carriers, which were out of port at the time of the attack After undertaking a series of daring and successful fast carrier raids, the first chance to engage the IJN battlefleet came at the Coral Sea ( May 3–8, 1942) That encounter was tactically a loss to the IJN but strategically indecisive Next came a spectacular American victory at Midway ( June 4–5, 1942), where the IJN suffered a catastrophic loss of fleet carriers and naval aircraft and pilots from which it never fully recovered The Guadalcanal campaign (1942–1943) provided more opportunities for small fleet actions in the battles of Cape Esperance (October 11–12, 1942); the Eastern Solomons (August 23–25, 1942); Santa Cruz (October 26 –27, 1942); and the naval Battle of Guadalcanal (November 12–15, 1942) Moreover, the U.S carrier-building program was greatly accelerated and naval aircraft production was also rising fast By the end of 1942 U.S naval aircraft production alone exceeded total Japanese warplane production and delivery USN submarines ultimately savaged the Japanese merchant marine and tanker traffic Yet, it was not until 1943 that the USN overcame prewar problems of too many and inadequate peacetime captains, poor combat doctrine, and defective torpedoes for its destroyers and submarines The latter particularly limited the effectiveness of initial war patrols by S-class and Fleet-class submarines The technical problem was resolved in 1943, about the same time that wartime experience led to replacement of one third of boat captains USN submarines accounted for 180 Japanese merchant ships in 1942 The number rose to 335 (including two dozen tankers) in 1943 By the end of the war American submarines sank 4.8 million tons of enemy shipping in the Pacific theater That was over 50 percent of all Japanese ships lost to all causes: land and sea-based aircraft, surface warships, submarines, and mines A high price was paid to achieve that count: submarines were lost in 1942, 17 in 1943, many more after that, as they closed around the home islands About 3,500 USN submariners lost their lives on war patrols by 1945, about 22 percent of the active force on 112 lost boats Still, combined with fleet air assault and land-based bombing, Japan was blockaded and slowly strangled militarily and economically by USN submarines During 1944 the USN diverged more clearly from the Army in its proposed strategy against Japan General Douglas MacArthur and his powerful political supporters wanted to press the New Guinea campaign, then advance against Rabaul and on to the Philippines Others argued that assaulting the Philippines had become unnecessary, that the main thrust should go through the Central Pacific straight toward Japan The decision was made by the Joint Chiefs of Staff to invade the Philippines, not least for political reasons pertaining to MacArthur’s influence in Washington and Roosevelt’s reluctance to take on that highly political general The decision to pursue both paths to victory led the Navy into two spectacular naval air and sea battles in 1944, at the Philippine Sea and Leyte Gulf At the same time, naval planners continued to prepare and carry out operations in the Central Pacific, moving to Iwo Jima and thence to Okinawa during the first months of 1945, preparatory to an all-out invasion of the home islands planned for later in the year The Navy faced its greatest danger in the Philippines and again at Okinawa from 1127