In late 1944, Washington decided to liberate the Philippines. The landing of American troops at Leyte Gulf sent the Japanese into planning four naval battles,the greatest of all naval battles: over 300 ships, 1,500 aircraft, and 200,000 men. The struggle involved every facet of naval warfare: surface ships, submarines, aircraft, and amphibious forces, and introduced a new tactic which would eventually kill more American sailors and sink more American ships than any other weapon used during World War 2: the kamikaze airplane. The battle for Okinawa lay just ahead.