United States Army in World War II: The War in the Pacific

The Approach to the Philippines

by Robert Ross Smith


. . . to Those Who Served

Table of Contents


The Author


Chapter 1: The Strategic Background

Determining the Strategy of the Approach—Acceleration of Pacific Operations in Early 1944—The New Directive for 1944

Chapter 2: Planning and Preparation for the Hollandia–Aitape Operation

Theater Organization—The Hollandia Area—The Decision to Take Aitape—The Forces and Their Missions—Logistics—The Hollandia Tactical Plan—Preliminary Operations and the Approach

Chapter 3: The Hollandia Operations

The Landings at Tanahmerah Bay—The 24th Division’s Drive to the Airfields—The Seizure of Hollandia Town—The Drive Inland from Humboldt Bay—Logistic Problems of the RECKLESS Task Force—The End of the Operation

Chapter 4: The Japanese: Pearl Harbor Through Hollandia

Strategy and Dispositions to April 1944—The Japanese at Hollandia

Chapter 5: Prelude to the Battle of the Driniumor

Securing the Airfield Area—Contact with the 18th Army on the East Flank

Chapter 6: Deployment for Battle

Reinforcement and Reorganization of the PERSECUTION Task Force—Gathering Combat Intelligence—The 18th Army Moves West

Chapter 7: The Battle of the Driniumor, Phase I: The 18th Army Attacks

Withdrawal of the PERSECUTION Covering Force—Restoration of the Driniumor Line—Operations West of the Driniumor—The Japanese Attack on the South Flank

Chapter 8: The Battle of the Driniumor, Phase II: The 18th Army Retreats

Securing the Afua Area—Envelopment to the East—The End of the Aitape Operation

Chapter 9: The Seizure of Wakde Island

The Sarmi–Biak Plan—The Wakde Plan—Preparations for the Capture of Wakde Island—Small-Island Warfare, Southwest Pacific Style

Chapter 10: Lone Tree Hill: The Initial Attacks

The Japanese at Wakde–Sarmi—The 158th Infantry Against Lone Tree Hill—Final Operations of the 158th Infantry

Chapter 11: Lone Tree Hill and Beyond

The 6th Division Against Lone Tree Hill—Final Operations in the Wakde–Sarmi Area—The Results of the Wakde–Sarmi Operation

Chapter 12: Biak: The Plan, the Landing, and the Enemy

The Biak Plan—The Landing—The Japanese on Biak

Chapter 13: West to Mokmer Drome

An Initial Reverse—Preparations for a New Attack—The Seizure of Mokmer Drome

Chapter 14: Frustration at Mokmer Drome

Reinforcements for the 186th Infantry—Operations North of Mokmer Drome—Allied Command at Biak

Chapter 15: The Japanese Reinforce Biak

Biak and Japanese Naval Plans—The KON Operation—Results of the KON Operation

Chapter 16: Biak: The Reduction of the Japanese Pockets

The Reduction of the West Caves—Securing the Western Area—The Reduction of the East Caves—The Reduction of the Ibdi Pocket—The End of the Operation

Chapter 17: Operations on Noemfoor Island

The Noemfoor Plan—The Landing—The Occupation of Noemfoor Island—Base Development on Noemfoor

Chapter 18: Airfields on the Vogelkop Peninsula

Early Plans for the Vogelkop—The Sansapor–Mar Plan—Operations in the Sansapor–Mar Area

Chapter 19: The Palaus and Morotai: Strategic and Tactical Planning

The Strategic Setting—The Objectives—Organization, Tactics, and Logistics

Chapter 20: The Morotai Operation

The Landing—Securing and Developing Morotai

Chapter 21: The Landings on Peleliu and Angaur

Preliminary Air and Naval Bombardment—The Peleliu Beachhead—The Decision to Land on Angaur—The Assault on Angaur—Securing Southern Angaur

Chapter 22: The Reduction of Northwestern Angaur

Into the Main Defenses—Overcoming the Last Resistance—Results of Operations on Angaur

Chapter 23: Securing Peleliu Island

Marine Operations in Southern Peleliu to 22 September—Dividing the Island—Northern Peleliu and the Offshore Islands

Chapter 24: Peleliu: The Last Resistance

Compressing the Umurbrogol Pocket—Entr’acte: The Relief of the 1st Marine Division—Overcoming the Final Resistance—Results of Operations in the Palaus—Conclusion: The Results and the Costs

Appendix A: Conclusion: The Results and the Costs

Appendix B: Bibliographical Note

Appendix C: List of Abbreviations



I. New Guinea

II. The Hollandia Operations, 22–26 April 1944

III. Securing the Beachhead, 23 April–4 May 1944

IV. Lone Tree Hill

V. Biak Landings and Seizure of Mokmer Drome, 27 May–7 June 1944

VI. Assault on Peleliu, 15–23 September 1944

VII. Assault on Angaur, 17–20 September 1944

VIII. Reduction of Northwestern Angaur, 21 September–1 October 1944

IX. Dividing the Island, 24–26 September 1944

Inline Maps

1. Situation in the Pacific, 12 March 1944

2. Hollandia Operation Area

3. Aitape Landings, 22 April 1944

4. Yakamul Area

5. Situation Along the Driniumor, Evening, 10 July 1944

6. Japanese Plan of Attack, 10 July 1944

7. Japanese Attack on Driniumor Line, Night, 10–11 July 1944

8. The TED Force Action, 31 July–10 August 1944

9. Wakde–Sarmi Area

10. Capture of Wakde Islands, 17–19 May 1944

11. Advance to Lone Tree Hill, 23–26 May 1944

12. TORNADO Task Force, Night, 30–31 May 1944

13. Schouten Islands

14. Bosnek–Sorido Coast

15. Attack North of Mokmer Drome, 11–15 June 1944

16. Securing the Airfields, 18–24 June 1944

17. Capture of Noemfoor, 2 July–31 August 1944

18. Vogelkop Operation, 30 July–31 August 1944

19. Palau Islands

20. Morotai Landings, 15 September 1944

21. Terrain of Umurbrogol Pocket

22. Marines at Umurbrogol Pocket, 30 September–15 October 1944

23. 321st Infantry at Umurbrogol Pocket, 16–25 October 1944

24. 323rd Infantry at Umurbrogol Pocket, 26 October–27 November 1944


1. American Casualties During the Approach to the Philippines: April–December 1944

2. Japanese Casualties, Defending the Approaches to the Philippines: April–December 1944


1. Operational Organization of the Southwest Pacific Area: April 1944

2. Air Organization for the Hollandia–Aitape Operations (Amphibious Phase)

3. Naval Organization for the Hollandia–Aitape Operations (Amphibious Phase)

4. Ground Organization for the Hollandia–Aitape Operations (Amphibious Phase)

5. Japanese Army Operational Organization in the Southwest Pacific Area: April 1944

6. Japanese Naval Operational Organization in the Central and Southwest Pacific Area: April 1944

7. The PERSECUTION Task Force: 22 April–4 May 1944

8. The PERSECUTION Task Force: 4 May–28 June 1944

9. The PERSECUTION Task Force: 28 June–11 July 1944

10. The PERSECUTION Task Force: 11 July–21 July 1944

11. The PERSECUTION Task Force: 22 July–30 July 1944

12. The PERSECUTION Task Force: 31 July–11 August 1944

13. The PERSECUTION Task Force: 11 August–25 August 1944

14. Organization for the Palau Operation


Lake Sentani Plain, Showing Airfields—Hollandia–Aitape Planners—Humboldt Bay—Tanahmerah Bay—Damaged Japanese Airplanes—Landings at Tanahmerah Bay—Unloading LSTs—Hand-Carrying Supplies—General Douglas MacArthur—LVTs Crossing Lake Sentani—Troops Unloading Supplies at Aitape—Yakamul Area—Tadji Fighter Strip—Driniumor River—Lt. Gen. Hatazo Adachi—The Afua Area—Artillery Supporting TED Force—Native Litter Bearers—Brig. Gen. Jens A. Doe—The Assault on Wakde Island—Enemy Defensive Positions on Wakde—LCM Ferry—Mokmer Drome, Biak—Biak Coast Line—Unloading at Biak—East Caves Area—Scene of Tank Battle—The Parai Defile—Men of the 162nd Infantry Seeking Cover—Disabled Japanese Tank—Infantrymen Moving Up to Attack—Entrances to the West Caves—Entrance to the East Caves—Dock Area, Biak—Base H and Hospital Areas on Biak—DUKW Burning on the Beach at Noemfoor—Paratroopers Landing on Noemfoor—Sansapor Planners—Bulldozer Clearing Jungle Undergrowth—Maj. Gen. Paul J. Mueller—LCIs at Morotai—Unloading at Morotai—RED Beach Unloading Operations—Saipan Town Area—Entrance to Lake Salome Bowl—Interior of Lake Salome Bowl—Mopping Up in Northwest Angaur—Southeast Corner of Umurbrogol Pocket—LVT Flame Thrower in Action—Moving into Mortimer Valley—Peleliu

The illustration on p. 146 is an Australian War Memorial photograph. All other illustrations in this volume are from the files of the Department of Defense.

Center Of Military History

United States Army: Washington, D.C.,

U.S. Army Center of Military History

Brig. Gen. Douglas Kinnard, USA (Ret.), Chief of Military History

Chief Historian, David F. Trask

Chief, Histories Division, Col. James W. Dunn

Editor in Chief, John Elsberg