The Philippines had suffered under the Japanese occupation. A highly effective guerilla campaign controlled sixty percent of the islands, mostly jungle and mountain areas. MacArthur had supplied them by submarine, and sent reinforcements and officers. Filipinos remained loyal to the United States, partly because of the American guarantee of independence, and also because the Japanese had pressed large numbers of Filipinos into work details and even put young Filipino women into brothels.
MacArthur returned to the Philippines in force on October 20, 1944. He waded in with Philippine President Sergio Osmeña, restaging the landing a second time for the newsreel cameras. The US Army forces met resistance, but steadily advanced, until the landings at Ormoc on December 7, 1944. Most of the fighting was at sea during the Battle of Leyte Gulf.
Ormoc saw the widespread use of kamikazes while the Americans ran into fortified positions and heavy artillery. MacArthur fought north through the Philippines all through the Fall of 1944, reaching Manila and the main island of Luzon in January 1945. The initial landing in Lingayen Gulf was unopposed, sparing the Japanese a prolonged bombardment as they retreated inland. The Japanese had a network of caves, pillboxes, and artillery. The defenders hoped to prevent an invasion of the home islands by offering a stiff resistance in the Philippines.