The Commonwealth government of the Philippines faced many challenges during World War II, including problems with national security, social issues, and the economy. When Japan attacked Pearl Harbor in 1941, the Philippines were also drawn into the war in the Pacific. Manila was occupied, and the battles of Bataan and Corregidor led to the deaths of many Filipino and American soldiers. The Philippine government went into exile under President Quezon, while the Japanese established a new government under Jose P. Laurel. Guerrilla groups resisted the Japanese occupation. After years of fighting, U.S. forces returned under General MacArthur in 1944 and liberated the Philippines by 1945, reestablishing the Commonwealth government.