The summer and fall of 1941 saw dramatic changes in U.S. military policy in the Philippine Islands. Contingency plans for war with Japan; including the immediate prewar plan, Rainbow 5, approved on May 14, 1941, called for American forces to withdraw into the Bataan Peninsula on the main island of Luzon until relieved by the U.S. Pacific fleet. Japan's occupation of French Indo-China in July 1941, however, forced the War Department to reassess the American position in the Southwest Pacific. On July 26, President Franklin D. Roosevelt nationalized the Philippine Commonwealth Army a