Summary
Highlights
By December 7, 1941, the Philippines had been a U.S. territory for over 40 years, serving as America's first line of defense against Japanese expansionism in the Pacific. Despite its strategic location, U.S. military leadership had concerns about its defensibility. Early simulations in 1914 showed Manila's vulnerability, and treaties like the Washington Naval Treaty (1922) limited fortification construction. War Plan Orange 3, updated in 1941, acknowledged the difficulty of a full defense and focused on denying Manila Bay's use to an invader and implementing a delay strategy.
The 1935 decision to grant the Philippines commonwealth status with autonomy complicated defense, shifting responsibility to the Philippine government but creating command and control issues. General Douglas MacArthur oversaw the creation of the Philippine Army, which faced significant challenges including language barriers among troops, a lack of officer schools, severe shortages of weapons, uniforms, housing, and military vehicles, and an unreliable communication infrastructure. This unpreparedness was particularly critical for a force tasked with a delaying action, which required high mobility and coordination.
Japan's occupation of French Indochina prompted President Roosevelt to freeze Japanese assets, halt shipments of vital resources, and plan for Philippine military reinforcement. These 'flexible deterrent options' aimed to prevent further Japanese aggression. Sensing an impending conflict, Roosevelt combined the Philippine Army and U.S. forces, placing MacArthur in command of U.S. Army Forces Far East (USAFFE). MacArthur was promoted to General and his defense plan, incorporated into the national War Plan Rainbow Five, called for a reinforced defense leveraging terrain and U.S. air power to repel attackers at the beaches by April 1942.
To bolster defenses, the Philippines received National Guard units, tank battalions (M3 Stuart tanks), P-40 Warhawks, and B-17 bombers. However, shipping shortages caused delays, with some aircrews arriving without their aircraft, forcing them to fight as infantry. MacArthur structured his command into five forces for integrated defense. Major General Jonathan Wainwright commanded the North Luzon Force, responsible for strategically important areas and the Bataan Peninsula. Brigadier General George M. Parker Jr. led the South Luzon Force, defending Manila and the southern tip of Luzon. Brigadier General William F. Sharp commanded forces in the Visayas and Mindanao. Major General George F. Moore led the Harbor Defense Force on Corregidor. MacArthur's reserve force, near Manila, included the Philippine 91st Division and the U.S. Philippine Division, along with a provisional tank group. Major General Lewis H. Brereton's Far East Air Force was the largest concentration of U.S. Army Air Corps aircraft outside the continental U.S. Logistical support was distributed from depots on Corregidor and Bataan. The 16th Naval District, under Rear Admiral Francis W. Rockwell, was also a vital defensive asset but operated independently of USAFFE, highlighting early challenges in joint command.
Japan, facing resource shortages, prioritized seizing the Dutch East Indies and Malay Peninsula and viewed the Philippines as an obstacle. To achieve their goals, they planned to neutralize the U.S. fleet at Pearl Harbor and address U.S. air and naval power in the Philippines. Lieutenant General Masaharu Homma's 14th Army was assigned to conquer the Philippines. The invasion plan, meticulously timed, aimed to destroy the Far East Air Force and secure airfields to gain air superiority. Initial landings would occur on Bataan Island (north of Luzon) and other locations like Aparri, Vigan, Legazpi, and Davao (Mindanao). Once air superiority was established and airfields secured, the main landings of the 14th Army would commence at Lingayen Gulf, north of Manila, with a smaller force landing at Lamon Bay to the south, converging on Manila for a combined assault to seize the capital and Manila Bay.
The attack on Pearl Harbor on December 8, 1941, marked the start of the Philippine invasion. MacArthur's forces, attacked months earlier than intelligence predicted, were severely under-equipped and undertrained, particularly the Philippine Army. Despite concerns about his air assets, delays and miscommunication prevented Major General Brereton's B-17s from striking Japanese airfields on Formosa. Japanese fighters and bombers from Formosa instead attacked Clark and Iba airfields with little opposition, destroying over half of the U.S. Army Air Force assets and establishing Japanese air superiority on the first day. Simultaneously, Japanese infantry landed unopposed on Bataan Island, securing the U.S. airfield there for their short-range fighters.
On December 9, Japanese bombers struck Nichols Field, destroying more aircraft. Recognizing the lack of air cover, Admiral Hart dispatched most of his Asiatic Fleet south to Australia. On December 10, the Japanese attacked naval facilities at Cavite. Japanese infantry, supported by naval air and gunfire, landed on Camiguin Island. Despite limited remaining U.S. air attacks sinking one Japanese minesweeper, Japanese forces established key lodgments at Vigan and Aparri and began moving south toward Manila along Route 3. On December 12, the Kimura detachment landed at Legazpi, routing untrained Filipino defenders and beginning a march north on Route 1 to link with future landings at Lamon Bay.
On December 22, the main Japanese effort, Homma's 48th Division (40,000 soldiers), landed at Lingayen Gulf, executing a multi-point landing plan. They met rough seas but weak resistance from the Philippine 11th Infantry Division at Agoo, Aren Gay, and Bauang. The Japanese quickly secured their beachheads and began moving inland. Notably, units of the Kamijima detachment seized Bauang and Negelian airfield, forcing the Philippine 71st Regiment and elements of the 11th Division to withdraw. Colonel Clinton A. Pierce's 26th Cavalry regiment of Philippine Scouts engaged Japanese forces advancing south along Route 3, attempting to delay them. Despite poor equipment and training among the larger Philippine forces, the 26th Cavalry put up fierce resistance, inflicting casualties on the Japanese and buying time. A platoon of American tanks sent to aid the defense at Damortis were quickly destroyed. Damortis fell by 19:00, and the 26th Cavalry, suffering heavy losses, continued a series of delaying actions while falling back.
By December 23, the 71st Division prepared defenses south of Sison, as the 26th Cavalry executed a rearward passage of lines—a difficult maneuver under enemy pressure. The 91st Regimental Combat Team reinforced the 71st Division. Japanese forces, reinforced by tanks and air support, eventually forced the 71st to fall back to Puzi Robio. The 26th Cavalry was ordered to establish an outpost further south. General Wainwright realized MacArthur's plan to repel the enemy at the beaches was failing. His request to withdraw behind the Agno River was approved, but he then learned that MacArthur had abandoned his original defense plan and reverted to War Plan Orange, which meant a planned withdrawal to Bataan. Wainwright also discovered MacArthur was moving his headquarters to Corregidor. This decision, though a 'bitter pill' for Wainwright, would ultimately delay Japanese war plans across the South Pacific.
On Christmas Eve, Lieutenant General Susumu Morioka's Lamon Bay force (7,000 soldiers of the 16th Division) landed at three locations, catching the South Luzon Force amidst repositioning. Despite some initial effective resistance by Filipino defenders, the Japanese swiftly secured their landings and began advancing on multiple fronts towards Manila and to link up with the Kimura detachment. Sustained air attacks overwhelmed defenders, forcing retreats. By the evening of December 24, MacArthur ordered General Parker of the South Luzon Force to organize the Bataan defense and prepare the peninsula's defenses. Meanwhile, the North Luzon Force also faced heavy fighting. The 26th Cavalry, despite valiant efforts and halting initial tank attacks, was eventually overwhelmed by Japanese reinforcements. Ordered to conduct a fighting retreat, the cavalry, reduced to 450 soldiers, delayed the enemy for over four hours before yielding Binmalonan. By the end of Christmas Eve, both Japanese Lingayen Gulf and Lamon Bay forces had established their beachheads and were poised to advance on Manila.
Japanese forces seized control of Manila, pushing remaining American and Filipino forces onto Bataan. President Roosevelt ordered General Douglas MacArthur to leave the Philippines. With no possibility of sending supplies or reinforcements, the remaining soldiers were left to rely on their own skills and courage.