The Military Advisor to the Commonwealth Government was US General MacArthur, who was assisted by Major Eisenhower and Major Ord; along with four officers from the Philippine Department, under Major General Holbrook (36-38) and Major General Grunert (40-41), as well as retired US Navy officer Sidney L. Huff.
OMACG produced a plan calling for a gradual 10-year build up so that the Philippines would have small regular and reserve armies, an air force, and a fleet of torpedo boats (the Offshore Patrol). The tactical organization of this army was based on divisions of ~7,500 troops.
The office drew up defense plans for the islands of Luzon, Cebu, Negros, Panay, Leyte, Mindanao, Bohol, Mindoro, and many of the smaller islands. The plans included the establishment of seacoast defenses along the seven straits which give access to the inland waters of the Philippines.
These plans did not involve the use of US forces, but were intended for use by district military commanders of the army which was to be created under the National Defense Act.
The seacoast defenses, mentioned above, were to consist, naturally, of heavy coastal guns. These defenses were scheduled to be completed in April of 1942. The War Department, at some time or other, had sent 24 155mm guns, without fire control equipment). Later, while assigned to USAFFE, MacArthur asked for 4 12in, 4 8in, and 22 additional 155mm guns, as well as 30 searchlights. This request was received in December, too late.
Upon the accidental death of Lieutenant Colonel Ord, in January of 1938, Major Sutherland was brought in as his replacement. Colonel Eisenhower left in December of 1939 and was replaced by Lieutenant Colonel Marshall. In October 1937, Captain Casey joined the group as an engineering advisor and later Major Marquat was appointed as an antiaircraft advisor. These men would stay with MacArthur throughout the war.
MacArthur argues, "A small fleet will have distinct effect in compelling any hostile force to approach cautiously. The only naval task is that of inshore defense. This will be provided by flotillas of fast torpedo boats, supported by an air force."
MacArthur adds, "These islands have enormous defensive advantages. Luzon has only 2 areas where a hostile army could land. Each of these positions is broken by strong defensive positions.
MacArthur continues, "When developed the Philippine Army will be strong enough to oppose any conceivable expeditionary force. By 1946, the Islands will be in a favorable posture of defensive security."
See also:
War Plans and Seacoast Defenses
Staff Changes
MacArthur's POV