EOA 13: JOINT OPERATIONS IN THE PHILIPPINES I

1. EOA 13: JOINT OPERATIONS IN THE PHILIPPINES I End state: Reoccupation of the Philippines is a United States obligation and a political necessity; seizure of the Philippines will facilitate the invasion of Japan. Condition (P/M): Avenge 1941-42 defeat (P); recapture of the Central Plains-Manila Bay region (M) COG: Enemy- 14th Area Army (O); Clark Field (S) Friendly- 6thArmy (O) OP Approach: Indirect. Invasion of Mindoro (shaping operations); diversionary operations; destruction of Japanese air power Decisive Points: Mindoro Air Base; Clark Field; Leyte Gulf LOO: Exterior LOOs. Broad front landings; frontal assaults; infrastructure repair and construction OP Reach: Bayambang-Wawa-Camiling line Tempo: Rate of march depended on infantry and supplies Simultaneity/Depth: Air and naval bombardment, mine sweeping operations, and securing routes 3-11 Phasing/Transitions: PH1- secure beachhead; PHII-maneuver south through central plains; PHIII-protect beachhead against counterattack; PHIV-secure and hold Central Plains-Manila Bay for 4-6 weeks. Culmination: Casualties/ supply issues sustained by 158th Infantry, 63rd and 172nd Infantry Regiment; decentralized logistical operation mitigated culmination of the majority of 6th Army forces. Risk (S/O/T): Unified command not established for Battle of Leyte (O); coordination between air, naval, and ground fires (O/T); tempo of I Corps created gaps (O); mitigated contested landing with loading of CBT forces vs. shore party materiel Theorist Synthesis: Geography and LOOs (Lloyd), Air power (Mitchell/Douhet), and deep distributed operations (Schneider) Timeline: War World II in the Pacific, Philippines 15 September 1944: U.S. Troops invade Morotai and the Paulaus.
20 October 1944: U.S. Sixth Army invades Leyte in the Philippines.
23-26 October 1944: Battle of Leyte Gulf results in a decisive U.S. Naval victory.
15 December 1944: U.S. Troops invade Mindoro in the Philippines. 22 December 1944: Leyte resistance ended 09 January 1945: U.S. Sixth Army invades Lingayen Gulf on Luzon in the Philippines.
03 February 1945: U.S. Sixth Army attacks Japanese in Manila.
16 February 1945: U.S. Troops recapture Bataan in the Philippines.
02 March 1945: U.S. airborne troops recapture Corregidor in the Philippines.
03 March 1945: U.S. And Filipino troops take Manila.
10 March 1945: U.S. Eighth Army invades Zamboanga Peninsula on Mindanao in the Philippines.

2. EOA 13: JOINT OPERATIONS IN THE PHILIPPINES BLUF: Macarthur developed an operational approach to defeat the Japanese on the Philippine IOT establish bases of supply/sustainment/support with in the range of the Japanese homelands. MAC developed a three phase operation utilizing a Decisive, Shaping and Sustaining framework. Within his campaign plan he used LOE- Military, Political & Security. Phase 1 was a Shaping OP to Establish conditions needed to conduct the decisive operation. The DO was the Attack on Luzon and the sustaining effort through ship to shore logistics until proper supply bases could be established on Luzon. Within Phase 1, Mac Identified Decision points to establish his forces and set conditions for phase 2. Phase 2 the shaping effort to Air and Naval Gun fire for the DO: the ground attack on Luzon at Lingayen Beach to the NW of Manila. Then the DO would continue the attack as the Main effort to Manila to secure the city, and then reconsolidate for future operations. They also planned further SO to attack and support the DO at Mike 7 and Mike 8. DO: Seizure of Luzon, specifically Manila and the central plain IOT EST the Air, Naval, Land Base of supply for future offensive projection. SO: Air Support, Naval support in south china sea, Leyte and Mindoro attacks to secure air bases. SU: SUST support by Army service and naval LOG elements. Strategic OBJ: secure a supply base within range of Japan. Operational OBJ: sieze Luzon, for power projection. IOT Enable Reconquista of the Philippines to set conditions for attacks on the Japanese homelands. Sea: 3rd fleet & 7th fleet, Air: 20& 21 & the 7th Air forces Given: Land 2 Armies (6th and 8th) Against: 14th army ~ 200k on islands. Considering: weather to attack China, Formosa. Japanese forces in the French-Indochina, the Kamikazes, balance between offensive momentum and logistical constraints. Had to choose between Formosa or Luzon. Allied prestige of liberating a former US colony.

3. EOA 13: JOINT OPERATIONS IN THE PHILIPPINES Sixth Army landing at Lingayen on Luzon How do we: 1. Land in the Lingayen area near of Luzon, 2. EST a Base of Ops/Sustainment 3. Advance south and seize Manila 4. BPT EST further control over Luzon. IOT: Secure a Base of Ops to provide power projection capability to attack the Japanese army, Secure sea LOCs for resupply. Given: 1st Corps, 14th Corps 4 DIV, 2 RCTs Against: Yamashita, 14th Army group, 275K troops In consideration of/to: terrain, Guerillas, time, Sust. DO: Securing of initial beachheads and continue to the attack to Manila SO: Leyte and Mindoro: land based airfields/ supply base Deception Ops: 8th Army at Southern Luzon, Formosa and Okinawa bombardments by 3rd fleet. SU: Initially decentralized under 6th Army, planed to transition to ASC (centralized ) Termination: Surrender of Luzon and Manila Military Endstate: Destruction of 14th Army group Japan, EST air bases, positioned for follow on operations. OBJ: Lingayen gulf, Clark airfield, Manila COG: Japanese Imperial Army, Manila for terrain Decisive points: San Jose, Lingayen air field, Air superiority LOO: Sequential: Air superiority, Lingayen, Clark field, manila, consolidate and reorganize. Anticipation: Def in depth at point of invasion, expect counter attack and massive causalities. Risk: Marginal beaches with sandbars, Broad front assault with reserves floating, C2 of ground forces was initially under naval control, advised by army general. Opportunity: Element of surprise, airfield location, ports Operational Reach: Planned Port Soual need Manila Culmination: possible if Army cannot get off the beaches BLUF: This is a four phase Joint Amphibious operation utilizing an indirect approach and the DO, SO, SU framework. Securing LUZON fulfills the military/political strategic objectives for the Philippines and postured allied forces for future offensive operations against the Japanese empire IOT attain their surrender and defeat. Strategic OBJs: Seize the Philippines IOT provide a base of OPS/Sustainment, for continued attack on the Japanese home islands, The Moral/Political OBJ to liberate the island. Defeat the Japanese forces in the Philippines, and Deny the Japanese Sea LOCs IVO the Philippines. Operational OBJs: Secure a beachhead IOT enable an attack on Manila, Secure usable airfields in Northern Philippines , enable 8th Army attacks on southern Luzon. Operational Environment: Archipelago in the SW Pacific requiring naval and air projection capabilities combined with sustainment and bombing operations, limited overland LOCs and restricted terrain. Char of FF: Aggressive firepower centric steam rolling joint force with long LOCs, strong industry/pop base. Char of ENY: Dug-in, honor bound, infantry centric army w/ poor naval support and minimal air support, intermittent sustainment.

4. EOA 13: JAPANESE OPERATIONS IN THE PHILIPPINES General Yamashita’s Elements of OP Art I End state: Delay the capture of Luzon as long as possible and fix U.S. forces IOT slow Allied momentum. Condition (P/M): Imperial General Headquarters prepare to write Luzon as a strategic loss (P); COG: Enemy- 6th Army (O); Friendly- 14th Area Army (O) OP Approach: Indirect. Static defense; deny use of Clark Field; delay the construction of Mindoro Air Base (sinking cargo and tankers); coordinated ground counter attack with the use of kamikaze attacks. Decisive Points: Invasion of Leyte; seizure of Clark Field LOO: Defend (establish a decisive battle area) three defensive groupings (Kembu, Shobu, and Shimbu Groups); counterattack; fighting withdrawal OP Reach: Limited to supplies and equipment on Luzon; power projection (air and naval support/attack) Tempo:The invasion on Leyte was a tactical surprised coupled with leadership and service tension between Japanese's Imperial Navy and Japanese Army. As a result were unable to achieve and/or maintain tempo. Simultaneity/Depth: Establish a series of defensive lines and strong points Phasing/Transitions: PH1- delay, PH2- defense in depth; PH3- counterattack; PH4- retrograde Culmination:lack of supplies to engage in a protracted defense of southern Luzon. Risk (S/O/T): Mitigatedinsufficient resources to conduct delaying action and defense in depth by abandoning the defense of Manila (O); Theorist Synthesis: Deep operations (Isserson), Axiomatic principles (Jomini), plan doesn’t survive first contact (Moltke), Sea Power(Mahan), and strong points in the rear of the enemy (Archduke Charles) Timeline: War World II in the Pacific, Philippines 15 September 1944: U.S. Troops invade Morotai and the Paulaus.
20 October 1944: U.S. Sixth Army invades Leyte in the Philippines.
23-26 October 1944: Battle of Leyte Gulf results in a decisive U.S. Naval victory.
15 December 1944: U.S. Troops invade Mindoro in the Philippines. 22 December 1944: Leyte resistance ended 09 January 1945: U.S. Sixth Army invades Lingayen Gulf on Luzon in the Philippines.
03 February 1945: U.S. Sixth Army attacks Japanese in Manila.
16 February 1945: U.S. Troops recapture Bataan in the Philippines.
02 March 1945: U.S. airborne troops recapture Corregidor in the Philippines.
03 March 1945: U.S. And Filipino troops take Manila.
10 March 1945: U.S. Eighth Army invades Zamboanga Peninsula on Mindanao in the Philippines.