In December 1941, MacArthur had one re-enforced US Infantry Division and ten divisions of almost untrained Philippine Army troops. His fight them on the beaches strategy was doomed. His troops were not trained enough to get into a mobile fight with the Imperial Japanese Army.
He then followed this up with criminal mismanagement of his logistics by not moving supplies to the Bataan peninsula before the war started. In fact he didn’t start moving supplies to Bataan and Corrigedor until well after the start of the war. Thousands of tons of supplies were destroyed instead of being sent to where they were needed. One tank company in central Luzon could only attack with one platoon instead of the whole company due to a shortage of fuel.
As I’ve said on the World War II plus 70 years threads, he should have been court-martialed for his defense of the Philippines.
Until the Kwantung army was defeated by the red Army at Khalkin Gol in August 1939, the Japanese drive for raw materials was west and north. At the same time, the entire U.S army totaled 187,893 men, the Philippines force was a garrison and no one was really expecting a Japanese drive to SE Asia.
It wasn't until the Aug 1941 embargoes of oil and other raw materials that Japan was thrown into crisis, unwilling to disengage from China as a prerequisite for lifting of the embargo, she chose war.
In the meantime, nothing had changed concerning the Philippines status, a small U.S. force was there and MacArthur had assurances of reenforcements and resupply, neither of which materialized although, on Dec 7, a number of units were either enroute or waiting to embark from the U.S. mainland to the Philippines.
26th Field Artillery Brigade
147th Field Artillery (75mm)(Trk Drawn) Regiment, South Dakota National Guard [At Sea]
148th Field Artillery (75mm)(Trk Drawn) Regiment, Idaho National Guard [At Sea]
2nd Bn 131st Field Artillery (75mm)(Trk Drawn) Regiment, Texas National Guard [At Sea]
34th Infantry Regiment [San Francisco Waiting to Embark]