Campaigns of The Pacific Theater in World War II

Divisions that Fought in the Pacific Theater

6th Infantry division 
7th Infantry division 
Americal Infantry division 
24th Infantry division 
25th Infantry division

27th Infantry division 

31st Infantry division 
32nd Infantry division 
33rd Infantry division 
37th Infantry division 

38th Infantry division 
40th Infantry division 

41st Infantry division 
43rd Infantry division 
77th Infantry division 

81st Infantry division

93rd Infantry division

96th Infantry division 

98th Infantry division 

Philippine division 
11th Airborne division 
1st Cavalry division

Campaign Overviews

A few hours after the raid on Pearl Harbor on 7 December 1941, Japanese aircraft attacked the Philippines. Three days later Japanese troops landed on Luzon. America�s meager air power in the islands was soon destroyed. Unable to obtain reinforcements and supplies, MacArthur could do nothing more than fight a delaying action. Between 16 and 18 December the few bombing planes that remained were evacuated, by their crews, to Australia, where US air power in the Far East was to be concentrated. Other members of the air units took up arms and fought as infantrymen in the battle that ended, at Bataan and Corregidor, with the loss of the Philippines in May 1942.

The war in the Central Pacific began with the Japanese attack on Pearl Harbor on 7 December 1941. Six months later an AAF task force took part in the Battle of Midway, in which a great Japanese fleet was defeated. But another year and a half elapsed before American forces began an offensive against Japanese positions in the Central Pacific. It was then, on 20 November 1943, that landings were made in the Gilberts, on Makin and Tarawa, with the Marines at the latter place becoming engaged in one of the bloodiest battles of the war.

On 3-4 June 1942, at the time of the Battle of Midway, a Japanese force attacked Dutch Harbor and inflicted considerable damage before it was driven off. The Japanese then occupied Attu and Kiska. For the rest of 1942 and into 1943, Eleventh Air Force struck enemy bases and installations whenever weather over the Aleutians permitted. The United States troops that landed on Attu on 11 May 1943 had possession of the island by the end of the month. The capture of Attu isolated Kiska, which was bombed repeatedly by American aircraft. The troops that invaded Kiska on 15 August 1943 discovered that the Japanese, under the cover of fog, had secretly evacuated their garrison.

In another effort to take Port Moresby the Japanese landed troops at Buna, Gona, and Sanananda in July 1942. At first the Allies could offer only feeble resistance to the enemy forces that pushed southward through Papua, but the Allies were building up their strength in Australia. By mid September Fifth Air Force had superiority in the air over New Guinea, and the Japanese drive had been stopped. The Allies then began to push the enemy back, with Fifth Air Force ferrying supplies and reinforcements to the troops fighting in the jungle. Buna was taken on 2 January 1943, and enemy resistance at Sanananda ended three weeks later.

On 7 August 1942 the first stage of the offensive began with landings by a Marine division on Guadalcanal and nearby islands. The Japanese reacted vigorously. They inflicted a serious defeat on Ghormley's naval forces in the Battle of Savo Island (8 August 1942), landed large numbers of reinforcements on Guadalcanal, and ultimately lost strong ground, air and naval forces in a desperate effort to hold Guadalcanal. Six major naval engagements were fought off the island. Air battles raged almost daily until the end of October 1942. On shore the issue was in doubt for almost three months. Before the island was finally secured in February 1943, the United States had committed two Marine divisions, two Army divisions, and an additional Army regiment to the fight. Late in February 1943 an Army division was unopposed in taking the Russell Islands, 35 miles northwest of Guadalcanal. The Allies thus firmly established themselves in the Solomons.

After the loss of Buna and Gona in New Guinea, the Japanese fell back on their stronghold at Lae. Their attempt to reinforce Lae by sea in March 1943 met with disaster when American and Australian planes sank most of the convoy in the Battle of the Bismarck Sea. Salamaua and Lae then became the objectives for an Allied advance along the northern coast of New Guinea. Fifth Air Force bombers attacked airfields at Wewak, 300 miles west of Lae, to neutralize them. The Allies dropped paratroops at Nadzab, just beyond Lae. Enemy resistance at Salamaua broke on 14 September 1943; Lae fell two days later. In the months that followed, MacArthur�s forces pushed westward, capturing some Japanese strongholds and bypassing others. After taking Hollandia in April 1944, the Allies attacked islands off the northern coast of New Guinea, taking Wakde and Biak in May, Owi in June, and Noemfoor in July. Sansapor on New Guinea also was gained in July. Aerial attacks on the Philippines began in August, and Morotai was seized in October to provide air bases for the invasion of the Philippines. Allied planes also bombed the oil center at Balikpapan and other targets in Borneo and Celebes.

Northern Solomons 22 February 1943 - 21 November 1944

After the conquest of Guadalcanal, Halseys forces, supported by Thirteenth Air Force, began a campaign to capture Japanese strongholds in the Northern Solomons. In February 1943 American forces landed in the Russell Islands to obtain an air strip. Air bases at Munda (New Georgia) and on Kolombangara Island were attacked as the Allies fought to gain superiority in the air. American troops landed on Rendova and on New Georgia at the end of June. The air base at Munda was taken in August, and the base on Kolombangara was neutralized. Landings were made in the Treasury Islands in October. Allied air power struck the great Japanese naval and air bases at Rabaul on New Britain to support the assault on Bougainville, which began on I November 1943. Enemy garrisons on Bougainville were contained, and other Japanese forces in the Northern Solomons were isolated. Although the enemy continued to resist, American air and naval power dominated the Solomons.

Eastern Mandates 31 January - 14 June 1944

After the operations in the Gilberts, American air and naval forces bombed and shelled Japanese bases in the Marshall Islands. In February 1944 American troops went ashore on Kwajakin, Roi, Namur, and Eniwetok. Other islands, including Jaluit and Wotje in the Marshalls and Truk in the Carolines, were bombed and shelled but were bypassed.

Bismarck Archipelago 15 December 1943 - 27 November 1944
To isolate and neutralize Rabaul on New Britain and the Japanese base at Kavieng on New Ireland, American forces landed at Arawe and Cape Gloucester in December 1943, on Green and Los Negros Islands in February 1944, and at Talasea on New Britain and on Manus Island in March. Some other enemy forces in the Bismarck Archipelago were bypassed.

Western Pacific 15 June 1944 - 2 September 1945

Attacks on Truk, where the Japanese had a major base, continued as preparations were made for the invasion of the Marianas. The American troops that landed on Saipan on 15 June 1944 met bitter opposition; but, after a desperate Japanese counterattack on 7 July, organized resistance soon terminated. Tinian, invaded on 25 July, was won by I August. Guam, which had been seized by the Japanese on 10 December 1941, was invaded on 20 July and regained after 20 days of fighting. With the conquest of the Marianas, the United States gained valuable bases for an aerial offensive against Japan itself. To provide bases for operations against the Philipgines, the Palaus were invaded in mid-September. Later, aerial attacks were made on Formosa to support the invasion of the Philippines and Okinawa.

Leyte 17 October 1944 - 1 July 1945

On 17 October 1944, after preparatory bombardment, the invasion of the Philippines got under way with the seizure of islands guarding Leyte Gulf. The landing on Leyte itself on 20 October was strongly contested by Japanese forces on land and at sea. Organized resistance on the island did not end until after Christmas, and mopping up operations continued for a long time. Meanwhile, at the end of October, the neighboring island of Samar was occupied with little difficulty.

Luzon 15 December 1944 - 4 July 1945

After Leyte came Mindoro, which was invaded on 15 December 1944, an air strip being obtained to provide a base for operations during the invasion on Luzon. American troops landed on the shores of Lingayen Gulf on g January 1945 and pushed to Manila, which the Japanese defended vigorously until 24 February. Rather than meet the Americans in a decisive battle, the Japanese decided to fight delaying actions in numerous places. Organized resistance ended in southern Luzon in April and in central and northern Luzon in June.

Southern Philippines 27 February - 4 July 1945
After Luzon had been invaded and Manila taken, a series of landings were made in the southern Philippines, on Palawan, Mindanao, Panay, Cebu, Negros, and other islands. In some places the Japanese offered little resistance; in others they held out for considerable time. The liberation of the Philippines was announced by MacArthur on 5 July 1945.

Ryukyus 26 March - 2 July 1945
The invasion of the Ryukyus was made by troops of the U.S. Tenth Army, which had been activated on 20 June 1944 with Lt. Gen. Simon B. Buckner, Jr., as commanding general. The Ryukyus campaign began on 26 March 1945 with the capture of small islands near Okinawa, where forward naval bases were established. An amphibious assault on Okinawa took place on 1 April, and the fighting lasted until June. Here, for the first time, Americans were invading what the Japanese defenders considered their home soil, and the defense was fanatic in the extreme. American troops suffered heavy casualties, and the Navy, too, had heavy personnel losses as Japanese suicide flyers, the Kamikazes, sank some 25 American ships and damaged 165 others in a desperate attempt to save the Ryukyus. Among the nearly 35,000 American casualties were General Buckner, who was killed on 18 June. He was succeeded by Maj. Gen. Roy S. Geiger, who was in turn succeeded by General Joseph W. Stilwell, who arrived to assume command of the Tenth Army on 22 June 1945.

Capture of the Ryukyus gave Allied naval and air forces excellent bases within 700 miles of Japan proper. Throughout June and July, Japan was subjected to increasingly intensive air attack and even to naval bombardment.

Sources: U.S. Army Center of Military History; Air Force Combat Units of World War II, Office of Air Force History; and US War Department Battles & Campaigns-World War II; United States Militart Academt Westpoint Department of History.