The region became important in the War in the Pacific upon the Netherlands' declaration of war on Japan after the bombing of Pearl Harbor. In 1942, the northern coast of West New Guinea and the nearby islands were occupied by Japan. By late 1942, most parts of the Netherlands Indies were occupied by Japan. Behind Japanese lines in New Guinea, Dutch guerrilla fighters resisted under Mauritz Christiaan Kokkelink. Allied forces drove out the Japanese after Operations Reckless and Persecution, the amphibious landings near Hollandia, from 21 April 1944. The area served as General Douglas MacArthur's headquarters until the conquest of the Philippines in March 1945. Over twenty U.S. bases were established and half a million US personnel moved through the area. West New Guinean farms supplied food for the half million US troops. Papuan men went into battle to carry the wounded, acted as guides and translators, and provided a range of services, from construction work and carpentry to serving as machine shop workers and mechanics. Following the end of the war, the Dutch retained possession of West New Guinea from 1945.