The Japanese attack on the Philippines occurred nine hours after their attack on Pearl Harbor on 7 December 1941. Despite that nine hour warning of the outbreak of hostilities with Japan, the commander of the United States army and air forces in the Philippines, Lieutenant General Douglas MacArthur, was paralysed by indecision during these crucial hours and failed to bring his forces to a state of readiness to meet a Japanese attack. MacArthur's indecision, combined with his poor military judgment and slackness in his command structure, led to the destruction of half of his air force on the ground and his troops being denied adequate supplies to withstand a lengthy siege.

Despite the hopelessness of their position, MacArthur ordered his troops to fight to the end. He did not remain to see that happen. He arranged his own escape with senior staff officers to Australia on 11 March 1942, leaving his sick and starving troops, their nurses, and American civilians to face the fury of a Japanese army commander humiliated by the stubborn resistance of the Americans. From the safety of Australia, MacArthur continued to order his troops in the Philippines to fight to the death. The American and Philippine defenders finally surrendered to the Japanese invaders on 6 May 1942 when they were too weak from sickness and starvation to resist any longer. The survivors were then subjected by the Japanese to death marches and other atrocities.

This map shows the Philippines at the time of the Japanese attack in December 1941. After the Japanese attack on Pearl Harbor, a thick belt of Japanese-occupied islands blocked support from the weakened US Pacific Fleet based at Hawaii.

There are two aspects of the Battle for the Philippines which should be of particular interest to Australians. The lengthy and heroic resistance by MacArthur's abandoned troops seriously disrupted the Japanese offensive timetable in the South-West Pacific region. Only 50 days had been allowed for the capture of the Philippines. It took Lieutenant General Homma 135 days to defeat the abandoned American and Philippine troops, and he needed massive reinforcements to do so. That stubborn resistance wrecked a Japanese division, tied up Japanese troops and resources in the Philippines, and provided vital time for Australian troops to return from the Middle East to defend Australia from Japanese invasion.

The Battle of the Philippines also provides an insight into the deeply flawed character and military judgment of General Douglas MacArthur, and helps to explain his inexcusable neglect of Australia's northern defences in 1942 and his indifference to the welfare of Australian troops fighting and dying on the Kokoda Track.

Japanese hostility to acquisition of the Philippines by the United States

The defeat of Spain in 1898 in the Spanish-American War brought a new and powerful player into the western Pacific region. As part of the fruits of its victory over Spain, the United States acquired the Philippines. Japan viewed this development with hostility. The United States possessed a powerful navy, and military planners in Japan realised that American occupation of the Philippines could hinder Japan's plans for aggressive territorial expansion into South-East Asia. To meet this potential challenge, Japan began to prepare for the possibility of armed conflict between the two countries. For their part, American military planners recognised the risk to the Philippines from Japan's expansionist foreign policy and they also began planning for possible armed conflict with Japan.

American strategies for the defence of the Philippines against Japan

The vastness of the Pacific Ocean created serious problems for the navies of the United States and Japan in the planning of their defensive strategies against each other. When Japan launched its devastating surprise attack on the United States Pacific Fleet at Pearl Harbor in Hawaii on 7 December 1941, and seized American island bases between Hawaii and the Philippines, one major aim was to facilitate capture of the Philippines without interference from the United States Navy. As American and Philippine troops fought a hopeless battle against invading Japanese troops between December 1941 and May 1942, any hope of reinforcement by the greatly weakened United States Pacific Fleet was negated by the Japanese Navy's control of the vast stretch of waters between Hawaii and the Philippines.

The American military planners were well aware of the difficulties involved in the defence of the 7,000 scattered islands of the Philippines archipelago against a powerful Japanese attack. Between World War I and World War II, strategic planning envisaged that the American garrison on the Philippines, then numbering about 17,000 troops, would be concentrated at Manila Bay on the large northern island of Luzon and hold the heavily fortified island of Corregidor and the Bataan Peninsula on the western side of the bay until they could be relieved by the United States Pacific Fleet sailing from Hawaii. This strategic plan for the defence of the Philippines against Japan was given the code reference "Plan Orange". Given the history of Japanese military aggression on the Asian mainland, Plan Orange assumed the probability of a surprise Japanese attack on the Philippines. Being fully aware of the strength of the Japanese Imperial Army and the power of the Japanese Imperial Navy, the American military planners realistically assumed that their Philippines garrison would probably be overwhelmed and forced to surrender before an American fleet could fight its way from Hawaii to Manila Bay.

In the event of a Japanese attack on the Philippines, Plan Orange envisaged that the defending forces would withdraw to the heavily fortified Bataan peninsula and the Island of Corregidor and await relief by the US Pacific Fleet sailing from Hawaii.

After the commencement of World War II, Plan Orange was largely superseded by a number of contingent plans which were collectively assigned the code reference "Rainbow". When Japan signed the Tripartite Pact in September 1940, and thus aligned itself with the Axis Powers Germany and Italy, this dangerous alliance forced the United States to reassess the various Rainbow scenarios. The Tripartite Pact recognised Japan's self-assumed role in establishing a "New Order" in East Asia, and provided for mutual assistance should any one of the three Axis powers be attacked by another country not already involved in the European conflict or Japan's undeclared war against China. The Germans and Italians wanted the pact to convey a clear warning to the United States that it would face war with Japan if it entered the war in Europe on Britain's side.

In the event of war between the three Axis powers and the United States, Admiral Harold R. Stark, Chief of Naval Operations in Washington, argued for containment of Japan in the western Pacific region and commitment of American military power in partnership with Britain against Germany and Italy as a priority. Instead of an offensive response to Japanese aggression in the western Pacific, as envisaged by Plan Orange, Admiral Stark proposed that the United States should maintain a defensive stance against Japan until Germany and Italy had been defeated. This strategic plan was strongly supported by the British Prime Minister, Winston Churchill, who had long argued that defeating Germany must be the first priority of both Britain and the United States. Admiral Stark's plan was approved by American and British military planners at joint meetings in Washington between January and March 1941. The plan was assigned the code reference "Rainbow 5", and became the unofficial policy of the United States and Britain in the event of the United States being drawn into war with the three Axis powers.

There were disturbing implications for both the Philippines and Australia in the Rainbow 5 plan. If Japan launched itself on the path of military aggression, Rainbow 5 would effectively give the Japanese a free hand to pursue that aggression in the western Pacific region until Germany and Italy had been defeated. The survival of the Philippines and Australia would both be gravely threatened by the plan. There would be no American naval reinforcements for the Philippines. The likely fate of an American garrison in the Philippines, in the event of war with Japan, was not disclosed to the garrison troops or the American people. The British government did not inform Australians that London and Washington had effectively abandoned their country to invasion in the event of war with Japan.

Fortunately for Australia, the smoking ruins of the United States battleship fleet at Pearl Harbor forced a rapid reappraisal of Pacific strategy by Washington. The whole of the central Pacific was now under threat from Japan, and the survival of Australia became of vital importance to the United States to provide a potential base for an American counter-offensive. This major change of American policy was fortunate for Australia because, once Singapore was lost to the Japanese on 15 February 1942, the British government made it clear to Australia that Britain was more concerned to save India rather than Australia from Japanese invasion. No British troops would be provided by Britain for the defence of Australia.