The United States had 146,000 troops in the Philippines, the majority of them Philippine locals. The fact that war was on the horizon was clear to all, and General MacArthur who had been the military advisor to the Philippine Government took direct control of the army.
The Japanese had planned to bomb the Philippines at the same time they attacked Pearl Harbor, but bad weather delayed the attack. Initially, the American aircraft in the Philippines was ready for a strike and had even taken to the air not to be caught on the ground. However, when the attack came at around noon on the 8th most of the American planes were on the ground refueling and preparing to attack Taiwan. The Japanese managed to destroy most of the American forces on the ground.

On December 8th the first Japanese troops began landing on Bataan Island. American aircraft attacked the troops landing. They damaged four trips and sank a minesweeper, but to no avail. The Japanese landed 2,500 men on December 12th in southern Luzon. They also attacked the American naval base at Cavite, which convinced the Navy to withdraw all of its shipped other than its submarines from the Philippines.

On December 22nd the main Japanese landing took place on the east coast of Lingayen Gulf. US forces were unable to do anything to stop the invasion. By the evening the Japanese troops had advanced ten miles into the island. The next day Japanese troops landed along the shore of Lamon Bay in southern Luzon. Manila was not defendable to the plan called to withdraw in the Bataan Peninsular. Over 80,000 soldiers and 20,000 refugees managed to retreat. The American forces defeated the initial Japanese attacks on the area. The American and Philippine soldiers managed to hold off the Japanese on the peninsula for all of January and February and most of March. In the middle of March General MacArthur was ordered to withdraw to Australia. By then new Japanese forces arrived, and on April 3 Japanese troops broke through, and on April 10th the last American troops surrendered.

That left the forces on the island of Corregidor. There were 11,000 army personnel on the Island which included deep tunnels that could not be destroyed by the constant Japanese air and artillery attacks. The Japanese landed forces on Corregidor on May 5th. On May 6th General Wainwright asked for terms of surrender. The Japanese commander demanded that all US troops in the Philippines surrender. Wainwright agreed, and the Philippines surrendered on May 8th