'Stalemate II' was the US definitive version of 'Stalemate I' within the 'Forager' campaign for the capture of key targets in the Palau islands group (15 September/25 November 1944).

By the summer of 1944 the successes of the US forces in General Douglas MacArthur’s South-West Pacific Area and Admiral Chester W. Nimitz’s Central Pacific Area had led to disagreement within the US Joint Chiefs-of-Staff Committee about which of two proposed strategies should be adopted to encompass the final defeat of Japan. The strategy proposed by MacArthur was posited on the recapture of the Philippine islands group followed by that of Okinawa island as the stepping stones to a direct assault on the Japanese home islands, while that preferred by Nimitz was posited on a more indirect approach in which the Philippine islands group would be bypassed, but Formosa and Okinawa islands would be taken as staging areas for an attack on the Chinese mainland paving the way to invasion of Japan’s southern islands. MacArthur’s and Nimitz’s plans each included the seizure of Peleliu, for different reasons, by Major General William H. Rupertus’s 1^st Marine Division.

President Franklin D. Roosevelt travelled to Pearl Harbor for a personal meeting with his two most senior commanders in the war against Japan, and selected MacArthur’s plan in preference to that of Nimitz. Before MacArthur’s forces attempted their invasion of the Philippines islands group, however, the Palau islands group in general, and specifically Peleliu and Angaur, were to be neutralised and an airfield built to protect the right flank of MacArthur’s assault on the Philippine islands group against Japanese air and naval interference from the east.

Peleliu is a small island about 6 miles (10 km) long and 2 miles (3.2 km) wide with an area of 5 sq miles (13 km²). Its southern half is relatively flat and protected by coral reefs, which made it a good site for a military airfield to protect the nearby Kossol Roads anchorage, and its northern half is dominated by the Umurbrogal ridge, a 300-ft (90-m) coral formation, which was heavily fortified by the Japanese during the war. The whole island was covered with dense jungle, and much of its coast was mangrove swamp.

The Japanese began to construct military facilities on Peleliu during the spring of 1939, when a force of 3,000 naval troops and 500 Korean labourers was sent to the island. A modern airfield had been completed on the island’s southern half by the end of the year, with single 6,000-ft (1830-m) and 3,500-ft (1065-m) runways and excellent facilities which included a two-storey reinforced concrete headquarters building. A satellite field was constructed on Ngesebus island, just to the north of Peleliu island, and a 500-yard (460-m) causeway was built to connect the two islands. The Japanese also constructed a network land transport facilities, these including roads along both the eastern and western sides of the Umurbrogal ridge. Because the island had no natural sources of water, the Japanese constructed a system of cisterns for trapping rainwater.

Peleliu produced small amounts of phosphate, which were refined at Akaraoro Point, the northern tip of the island. This had been converted into a blockhouse before 'Stalemate II'. The Japanese sited most of their beach defences along the south-west coast, which they correctly estimated would be the location of any US landing as the reef here narrowed to 600 to 700 yards (550 to 640 m) in width. The majority of the Japanese defenders were dug in on the Umurbrogal ridge, however.

By the summer of 1944, the Japanese forces in the Palau islands totalled about 30,000 men, centred on Lieutenant General Sadae Inoue’s 14^th Division (2^nd, 15^th and 59^th Regiments), which its commander deployed mainly on Babelthuap, by far the largest of the islands of the Palau group and located at the group’s northern end. Some 5,300 combat troops of the reinforced 2^nd Regiment but also including other army elements such as the 346^th Independent Battalion of the 53^rd Independent Mixed Brigade, the 3/15^th Regiment, and a miscellany of field artillery, anti-aircraft artillery and one company of tanks increasing the total to 6,500 combat troops. Japanese navy elements on the island included detachments of the 43^rd and 45^th Base Forces, two anti-aircraft units, three construction battalions, and 1,400 air service personnel, for a total of about 3,000 naval personnel. There were also a number of Korean and Okinawan labourers, and another 1,200 or so men arrived later as reinforcements or the survivors of failed raids.

2^nd Regiment of the 14^th Division, one battalion of the 54^th Independent Mixed Brigade and one other battalion, and 5,000 Korean and Okinawan labourers were stationed on Peleliu. Colonel Kunio Nakagawa, commander of the 2^nd Regiment, was entrusted with the task of preparing the island’s defence.

After their defeats in the Solomon, Gilbert, Marshall and Mariana island groups, the Japanese army had assembled a research team to develop a new combination of strategy and tactics for the defence of islands. The team quickly abandoned the earlier concept of attempting a tenacious and costly defence of the beach area, followed by suicidal Banzai charges that were still more costly and had by now been revealed to be fruitless, in favour of tactics that were designed to disrupt any US landing, to form a 'honeycomb' system of fortified positions farther inland, to replace the banzai attacks with co-ordinated counterattacks, and to draw the US forces into an attritional campaign that would exhaust the invaders and compel them to commit ever more resources.

In accordance with this new thinking, Nakagawa concentrated his defences inland and, exploiting every feature of the rugged terrain to his advantage, supervised the construction of a system of heavily fortified bunkers, caves, and underground positions. The main strength of Nakagawa’s defence system was based on Peleliu’s highest point, Umurbrogol 'mountain', a terrain complex which comprised a number of hills, steep ridges and deep defiles. Located in the island’s centre and dominating the peninsula stretching out north-east from Peleliu’s wider southern half, Umurbrogol ridge overlooked much of the island including the crucial airfield. The Umurbrogol complex contained some 500 limestone caves, connected by tunnels. Many of these were former mine shafts which had been turned into defence positions, the engineers adding sliding steel armour doors with multiple openings for artillery and machine guns. The Japanese dug and blasted other positions throughout the Umurbrogol complex for 81- and 150-mm (3.2- and 5.9-in) mortars as well as 20-mm cannon. Further strength was added by the presence of light tank unit and an anti-aircraft detachment. The cave entrances were built at an angle to improve their ability to survive grenade and flamethrower attacks, and the caves and bunkers had been turned into a giant defensive complex by the mass of tunnels that was driven through the centre of the island. This made it possible for the Japanese to evacuate or reoccupy positions as needed, and to take full advantage of interior lines of communication as the US forces advanced.

The Japanese also used the probable location of the US landing for the development of an important defensive feature. The northern end of the landing beaches faced a coral promontory which was 30 ft (9.1 m) high and overlooked the beaches from a small peninsula later known to the US forces as 'The Point'. Holes were blasted into the ridge to accommodate a 47-mm gun and six 20-mm cannon. The positions were then sealed to leave just a small firing slit facing the assault beaches.

Similar positions were created along the 2-mile (3.2-km) stretch of landing beaches. The Japanese also strewed the beaches with thousands of obstacles for the landing craft. These obstacles were mostly mines and heavy artillery shells, buried with their fuses exposed to explode on being run over. A battalion was placed along the beach to defend against the landing, but these defences were meant simply to delay and not to defeat the US landing and advance. The Japanese would then channel the US advance inland to the mauling area between the fortified ridges and hills.

The US invasion tactics were essentially unaltered from those which had generally succeeded in previous amphibious assaults despite the fact that the US forces had suffered 3,000 casualties and two months of delay in the face of entrenched Japanese defenders in 'Horlicks' (the Battle of Biak) in May and June 1944.

Despite Rupertus’s assertion that he expected a tough fight but of only short duration, with the Japanese defence collapsing on only a few days, the Peleliu campaign in fact developed into one of the bloodiest campaigns of the World War II in the Pacific theatre for a number of reasons including the fact that it was perfunctorily planned and poorly executed on the US side. No American had ever set foot on the island, the heavy jungle had foiled aerial photo-reconnaissance, concealing the jagged ridges dominating the airfield, and the Americans considerably underestimated the Japanese strength.

For 'Stalemate II' the US planners opted for Rupertus’s 1^st Marine Division to make its landing on the south-western beaches as these were close to the airfield. The division had been had hit in earlier campaigns, and its ranks now included large numbers of inexperienced replacements who had been little improved by the basing of the formation in primitive conditions on Russell islands group in the Solomon islands group. Colonel Lewis B. Puller’s 1^st Marines was to land at the northern end of the beaches, Colonel Harold D. Harris’s 5^th Marines in the centre, and Colonel Herman H. Haneken’s 7^th Marines at the southern end; the 11^th Marines, the division’s artillery regiment, was to come ashore after the infantry regiments.

The plan was then for the 1^st and 7^th Marines to drive inland, proving flank protection for the 5^th Marines' left and right flanks respectively, and thereby facilitating the 5^th Marines' advance to take the airfield straight ahead of the centre of the selected landing beach. The 5^th Marines were then to push forward to the eastern shore, where the land is low-lying and swampy, thereby cutting the island in half. The 1^st Marines would push north into the Umurbrogol complex, and the 7^th Marines would clear the southern end of the island. Only one battalion was left behind in reserve, with the 10,995 men of Major General Paul J. Mueller’s 81^st Division of the US Army available for support from Angaur, just to the south of Peleliu.

It was on 4 September that the 17,490 men of the 1^st Marine Division departed their base on Pavuvu island, just to the north of Guadalcanal for the 2,100-mile (3380-km) passage across the Pacific to Peleliu island. The landing was preceded by the operations of a US Navy underwater demolition team, which was brought in by the submarine Burrfish, cleared obstacles from the beaches and coral heads from the beach approaches, and then on 12 September warships began their preliminary bombardment of Peleliu.

The revision of 'Stalemate I' into 'Stalemate II' had taken account of the fact that the main Japanese strength was located in the northern part of the Palau islands, and the US plan was now to take only the two southern islands (Peleliu and Angaur) so that the Kossoi Passage could be cleared of mines and the anchorage used for the forthcoming invasion of the Philippine islands group. The target area was softened up by naval gunfire bombardment and air attacks from the surface combatants and escort carriers of Vice Admiral Theodore C. Wilkinson’s Task Force 31 (Joint Expeditionary Force or 3^rd Amphibious Force), whose ground forces were incorporated in Major General Roy S. Geiger’s III Amphibious Corps.

After the raids by Vice Admiral Marc A. Mitscher’s TF38 from 6 to 8 September, the naval bombardment of Peleliu and Angaur started on 13/14 September using Rear Admiral Jesse B. Oldendorf’s fire support group 1. There were also three fleet carriers and five light carriers under the command of Rear Admiral William D. Sample for the provide of more distant cover, and in the pre-landing bombardment these forces dropped 519 16-in (406-mm) and 1,845 14-in (356-mm) shells, as well as 1,793 500-lb (227-kg) bombs on an island of only 5 sq miles (13 km²). Tactical air support was provided by Rear Admiral Ralph A. Ofstie’s Task Group 32.7 of between seven and 11 escort carriers, whose aircraft flew 382 sorties on the day of the landing.

On 16 August the destroyer Wadleigh was damaged by a mine in the Kossol Passage.

The attack on Peleliu and Angaur was entrusted to Rear Admiral George H. Fort’s TF32 (Western Attack Force), and on 15 September some 17,490 men of the Northern Attack Force’s 1^st Marine Division began to land on Peleliu in LVT amphibious tractors and DUKW amphibious trucks, and supported by armour landed from LCT tank landing craft deployed from LSD dock landing ships.

The Americans clearly believed that the bombardment had been successful, Oldendorf going to far as to claim that the US Navy’s warships had run out of targets. The reality was altogether different, for the vast majority of the Japanese positions emerged from the bombardment completely unscathed: even the battalion left to defend the beaches had suffered only minor losses. During the assault, the Japanese had maintained a very strict fire discipline to avoid giving away their positions. However, the bombardment did destroy all of the Japanese aircraft on the island, as well as the buildings surrounding the airfield. Yet the Japanese remained in their fortified positions, safe and undetected but poised to tackle the Us forces after they had landed.

The 'Stalemate II' landing began at 08.32 on 15 September with the 1^st Marines coming ashore in the north on White beach, and the 5^th and 7^th Marines in the centre and south on Orange beach. As they approached the beaches, other landing craft came under a devastating crossfire as the Japanese opened their steel defensive doors and swept the sea with heavy artillery fire, and the positions on the coral promontories guarding each flank fired on the marines with 47-mm guns and 20-mm cannon. By 09.30 the Japanese had destroyed 60 LVTs and DUKWs.

The 1^st Marines were pinned by heavy fire from 'The Point', and Puller escaped only narrowly when a shell hit his LVT. Puller’s whole communications team had already been destroyed on its way to the beach by a hit from a 47-mm high-velocity round.

The 7^th Marines in the south faced a similar problem with fire from their right flank. Many of their LVTs were destroyed as they approached the beach, leaving their occupants to wade ashore through the coral reef in water chest-deep or higher while being raked by Japanese machine gun fire. The marines' initial casualties were very high, and many marines who did manage to reach the beach had lost their rifles and other essential gear.

It was the 5^th Marines who made the best progress on D-day, largely as a result of their distance from the heavy gun emplacements guarding the Japanese left and right flanks. The 5^th Marines advanced toward the airfield, but were met by Nakagawa’s first counterattack. The Japanese tank company swept across the airfield to push the marines back, but was soon taken under fire by every available tank, howitzer, naval gun and dive-bomber. Technically obsolete, and lacking both firepower and armour, the 13 Japanese light tanks were quickly destroyed, together with their accompanying infantry.

By the end of 15 September the marines held their 2-mile (3.2-km) stretch of assault beach but little else. Their biggest push in the south had managed to move about 1 mile (1.6 km) inland, but the 1^st Marines to the north had achieved very little progress because of the relentless flanking fire from 'The Point'. The marines had suffered 1,100 casualties (200 dead and 900 wounded) during the day. As noted above, Rupertus had believed the Japanese would quickly crumble as their perimeter had been broken, but the US forces were still unaware of the change of Japanese tactics and their implications in fighting a protracted defence.

On 16 September the 5^th Marines moved forward to take the airfield and drive toward toward the eastern shore. They swept across the airfield under heavy artillery fire from the higher land to their north, and suffered heavy casualties. After capturing the airfield, they were able to advance to the eastern side of Peleliu, whose shore they reached on 19 September, thereby cutting the defence in two and leaving the island’s southern defenders to be wiped out by the 7^th Marines, and then advanced to the north and to the south along this low-lying part of the island, reaching its northern end, along a chain of small islands, on 21 September and then crossing two day later to the small island in the centre of the large bay’s entrance, and arriving at its southern end, just above a smaller bay, by 22 September. Beyond this bay the south area of the island’s main body was strongly contested by the Japanese, who still occupied numerous pillboxes.

The temperature remained at about 46° C (115° F), and the marines lost many men to heat exhaustion: moreover, the marines' only available water supply was contaminated with oil. Even so, progress was made, albeit only slowly, and by 23 September the 5^th and 7^th Marines had accomplished their objectives, taking and holding the airfield and the southern portion of the island. After capturing the airfield, the marines brought it back into service as early as 18 September, when Taylorcraft L-2 'Grasshopper' observation aircraft of the VMO-1 squadron started to fly spotting missions for the marines' artillery and also for naval gunfire. On 26 September, Vought F4U Corsair fighter-bombers of the VMF-114 squadron landed on the airstrip, and almost immediately started to fly dive-bombing missions across Peleliu: by 1 October the 11^th Marine Air Group was based there, and one week later a 6,000-ft (1830-m) bomber runway had been completed. The Corsair warplanes also introduced two new weapons to Peleliu: air-launched rockets were able to blow open cave entrances for the infantry, and napalm (used for only the second time in the Pacific theatre) was able to burn away the vegetation hiding spider holes, usually killing the holes' occupants in the process.

The Japanese strongpoint at 'The Point' continued to cause heavy casualties across the landing beaches, and Puller ordered Captain George Hunt, commanding Company K, 3/1^st Marines, to capture the position. The company approached 'The Point' with little in the way of supplies and only limited firepower as it had lost most of its machine guns while approaching the beach. One platoon was pinned down for nearly an entire day in a vulnerable position between fortifications, and the rest of his company was also in extreme danger after the Japanese split the company’s line, cutting off its right flank. However, one platoon began knocking out the Japanese gun positions one after another: using smoke grenades for cover, the marines swept through each hole, destroying the positions with rifle grenades. After knocking out the six machine gun positions, the marines finally faced the cave occupied by the 47-mm gun which had severely damaged the waves of landing craft. A lieutenant blinded the gun’s crew with a smoke grenade, allowing Corporal Henry W. Hahn to throw a grenade through the cave’s aperture: the grenade detonated the 47-mm ammunition, forcing the Japanese to leave the cave and then be shot.

Company K had captured 'The Point', but Nakagawa now committed his men in a series of counterattacks intended to retake it. During the next 30 hours there were four major counterattacks against the single marine company, which was desperately short of supplies and out of water. By the time reinforcements arrived, the company had been reduced to 18 men, and had suffered 157 casualties during the battle for 'The Point'.

After securing the airfield, the 5^th Marines were sent to capture Ngesebus island, just to the north of Peleliu, as this was occupied by several Japanese artillery positions and was also the site of an incomplete airfield. The little island was connected to Peleliu by a small causeway, but Harris opted instead for a shore-to-shore amphibious landing as he felt that the causeway would have been pre-registered by the Japanese artillery. Harris co-ordinated a preliminary bombardment of the island on 28 September by army 155-mm (6.1-in) guns, naval gunfire, the 11^th Marines' howitzers, strafing runs by VMF-114’s Corsair fighter-bombers, and 75-mm (2.95-in) fire from the howitzers of approaching LVTs. Unlike the naval bombardment of Peleliu, Harris’s bombardment of Ngesebus island was very effective and neutralised most of the defenders. The marines still faced opposition in the ridges and caves, but the island fell quickly, with relatively light casualties for the 5^th Marines: for the loss of 15 men killed and 33 wounded, the 5^th Marines inflicted 470 casualties on the Japanese.

After taking 'The Point', the 1^st Marines moved to the north into the pocket on Umurbrogol ridge, which was soon nicknamed 'Bloody Nose Ridge' by the marines. Puller led his men in numerous assaults, but every attack was quickly snuffed out by the Japanese. The 1^st Marines were trapped in the narrow defiles between the ridges, with each ridge fortification supporting the other with devastating crossfire. The marines suffered a steady flow of casualties as they advanced slowly through the defiles and across the ridges. Yet again, the Japanese showed excellent fire discipline, striking only when they could inflict maximum casualties. As the marine casualties mounted, Japanese snipers began to target stretcher bearers, knowing that if two stretcher bearers were injured or killed, more would be sent forward to replace them, thereby providing the snipers with a steady flow of victims.

Rather than the Banzai charges which the marines had expected, moreover, the Japanese now infiltrated the US lines at night to attack the marines in their foxholes. The marines therefore started to use two-man foxholes, so that one marine could sleep while the other kept watch for infiltrators.

A notably bloody episode on 'Bloody Nose Ridge' occurred when Major Raymond Davis’s 1/1^st Marines attacked Hill 100 and, in the course of six days of combat, suffered 71% casualties. Captain Everett Pope led his company deep into the defile/ridge complex, leading his remaining 90 men to take what he believed to be Hill 100. It took an entire day of bloody fighting to reach what he thought was the crest of the hill, only then finding that it was merely the nose of yet another ridge, occupied by still more Japanese defenders. Trapped at the base of the ridge, Pope set up a small defensive perimeter, which the Japanese attacked right through the night. The marines soon exhausted all their rifle ammunition, and had to fight off the attackers with knives, lumps of coral rock and empty ammunition boxes. Yet Pope and his men managed to hold out until dawn, when the surviving nine marines evacuated the position. The Japanese eventually inflicted 60% casualties on Puller’s 1^st Marines, who lost 1,749 out of about 3,000 men.

After six days of fighting in the defiles and ridges of Umurbrogol, Geiger, commanding the III Amphibious Corps, sent elements of Major General Paul W. Mueller’s 81^st Division to Peleliu to relieve the regiment: at the time of highest but misplaced US optimism about 'Stalemate II', on 17 September Wilkinson had come to the conclusion that the 81^st Division, the floating reserve, would not be needed on Peleliu island and sent most of it to take Angaur island. The 321^st Regimental Combat Team landed on the western beaches of Peleliu, near the northern end of the Umurbrogol complex, on September 23, and part of the regiment headed to the north along the island’s west coast parallel to the flank of the Umurbrogol complex and the last of the northernmost Japanese positions on Mt Kamilianlul before dividing into two columns at advanced the rest of the way along the west and east coasts of the northern peninsula past Mt Amiangal to reach the island’s northern tip on 30 September.

Farther to the south, in the Umurbrogol complex, the 321^st Infantry and the 5^th and 7^th Marines all took their turns in the front line, and all suffered similar casualties. By mid-October, the 5^th and 7^th Marines had each suffered about 50% casualties as the two regiments clawed their way through the ridges. Geiger then decided to replace the 1^st Marine Division with the rest of the 81^st Division. The 323^rd Regimental Combat Team landed on 15 October, on Peleliu’s western side just forward of the US positions at the southern edge of the Umurbrogol complex, and by the third week of October almost all of the marines had been evacuated back to Pavuvu.

The army troops headed off to battle the remaining Japanese on 'Bloody Nose Ridge', where the fighting lasted for another month before the US forces finally secured the island. Nakagawa finally burned his regimental colours and committed ritual suicide. A Japanese lieutenant with 26 soldiers of the 2^nd Regiment and eight sailors of the 45^th Guard Force held out in the caves of Peleliu until 22 April 1947, surrendering only after a Japanese admiral convinced them the war was over. This was the last official surrender of World War II.

The reduction of the Umurbrogol mountain complex is considered to be the most difficult fight that the US military encountered in World War II.

The 1^st Marine Division had been grievously mauled and remained out of action until the 'Iceberg' invasion of Okinawa on 1 April 1945. In total the 1^st Marine Division suffered 6,562 casualties (1,252 men killed, 5,274 men wounded and 36 men missing) during its month on Peleliu, more than one-third of the whole division. The 81^st Division suffered 3,278 casualties (542 men killed and 2,736 men wounded), bringing the US losses on the island to 9,840 (1,794 dead, 8,010 wounded and 36 missing).

Of the Japanese garrison, all but 202 men (19 soldiers and 183 labourers) were killed or held out.

The battle for Peleliu was controversial as the island lacked any real strategic value. The airfield was of little use for the attack on the Philippine islands group. The island was not used for a staging operation in subsequent invasions: Ulithi atoll, in the Caroline islands group to the north of the Palau islands group, was used as a staging base for the 'Iceberg' invasion of Okinawa. But the battles for Angaur and Peleliu revealed to the US forces the new Japanese tactics for island defence, and this proved important in the planning of 'Detachment' and 'Iceberg' against Iwo Jima and Okinawa respectively. The naval bombardment before 'Detachment' was only slightly more effective than at Peleliu, but that before 'Iceberg' was telling in the extreme. Frogmen performing underwater demolition at Iwo Jima confused the Japanese by sweeping both coasts, thereby confusing them about the location of the landings, but later alerted the Japanese defenders to the exact assault beaches at Okinawa. US ground forces at Peleliu gained experience in assaulting heavily fortified positions such as they would find again at Okinawa.

On 17 September, meanwhile, the Southern Attack Force (Mueller’s 81^st Division with the 321^st, 322^nd and 323^rd Infantry) was landed on Angaur. By mid-1944 Inoue had stationed some 1,400 men of the 1/59^th Regiment, under the command of Major Ushio Goto, on the island. Other Japanese forces in the Palau islands group, it should be noted, included two battalions each of the 15^th and 59^th Regiments plus four battalions of the 53^rd Independent Mixed Brigade under the command of Major General Takao Mabuchi on Babelthuap; and the Japanese navy’s 30^th Base Force, 43^rd and 45^th Guard Forces, and air service personnel on Babelthuap, Koror ands other islands.

Separated from Peleliu by a 6-mile (9.75-km) strait, Angaur is a small volcanic island only 2.25 miles (3.6 km) long and with an area of 2,000 acres (809/5 hectares). The island is generally flat with the exception of a set of coral ridges reaching to 200 ft (60 m) on the island’s north-western tip, and these had been rendered more rugged by the mining of phosphate. There were also two swampy areas, one of them natural in the south-eastern part of the island, and the other the result of phosphate mining near the island’s centre. There was a phosphate processing facility on the island’s west coast, and this was connected with the mining area by a narrow-gauge railway. There was no airfield and the island had no anchorage: ships were loaded with phosphate by means of a floating conveyor belt system.

The garrison of Angaur late in 1944 was 1,400 men of one infantry battalion and some support elements.

Bombardment of the Japanese positions on Angaur by the battleship Tennessee, as well as cruisers and destroyers, as well as a sustained air campaign by the Douglas SBD Dauntless dive-bombers of the fleet carrier Wasp began on 11 September and six days later, on 17 September, men of the 81^st Division landed on the north-eastern and south-eastern coasts. Mines and congestion on the beach initially gave more trouble than the inevitable Japanese counterattacks.

Resistance stiffened as the Americans advanced on the 'Bowl', a hill near Lake Salome in the north-west of the island and the position in which the Japanese planned to make their last stand. From 20 September a battalion of the 322^nd RCT repeatedly attacked the 'Bowl', but the 750 defenders repulsed them with artillery, mortar and machine gunfire. Gradually the combination of hunger, thirst, artillery fire and air attack took their toll on the Japanese, however, and by 25 September the US infantry had penetrated the 'Bowl'. Rather than fight for possession of the caves, the US troops used bulldozers to seal the entrances.

By 30 September the island was secure, the US forces having suffered the loss of 260 men killed, 1,354 wounded and 940 incapacitated by heat exhaustion, accident and sickness, and the Japanese having lost 1,338 men killed, a mere 59 being captured. Construction of an airfield started on 20 September, even as the battle continued, and this received its first transport aircraft on 15 October. Two 6,000-ft (1830-m) runways were operational two days later, and Consolidated B-24 Liberator heavy bombers started to operating from the airfield on 21 October

But the delay in the start of the operations to take the two southerly islands of the Palau group meant that their airfields were not ready in time for the start of the 'King II' operation against Leyte island in the Philippine islands group during October 1944. Halsey had argued before the invasion of the Palau islands group that the entire operation was unnecessary, and military historians have in general agreed with him, suggesting that the main benefit was the combat experience gained by the 81^st Division, which moved on directly from Angaur to Peleliu to aid Rupertus’s 1^st Marine Division still encountering extremely stiff Japanese resistance in Peleliu’s central highland.

The last stage of the 'Stalemate II' campaign was the seizure of Ulithi atoll (between the Palau islands group and the Mariana islands group) by Colonel Watson’s 323^rd Regimental Combat Team of the 81^st Division, the landing force being delivered by Rear Admiral William H. P. Blandy’s improvised TG33.19.

A large atoll at the western end of the Caroline islands group, some 370 miles (595 km) to the north-east of the Palau islands group and a similar distance to the south-west of Guam, Ulithi has a very substantial anchorage, which is capable of accommodating 700 ships. This anchorage is sheltered by a substantial ring of islets some 22 miles (35.5 km) long and 14 miles (22.5 km) wide. Nearby Ngulu atoll has an anchorage capable of accepting another 300 ships.

Nimitz, an officer with a love of maps, noticed the atoll, realised its strategic potential, and arranged for it to be seized during the 'Stalemate II' campaign at a time when there was still unwarranted optimism about progress on Peleliu.

The landing was effected on 23 September with support provided by TG30.8, which had approached the island on the previous day with the light cruiser Denver and the destroyers Ross and Bryant. The US landing then found that the Japanese had pulled out earlier in the month.

The Japanese submarines I-44, Ro-47 and I-177 were deployed against the landing fleet, but met with no success and the last two were sunk on 26 September and 3 October respectively by the destroyer escorts McCoy Reynolds and Samuel S. Miles.

Unloading on Ulithi was completed in two days, and a 'Seabee' construction battalion then arrived. The excellent anchorage at Ulithi was soon developed as the US Navy’s main forward fleet base in the Pacific (in March 1945, for example, there were at one time as many as 617 ships in the lagoon), taking over from Eniwetok and in essence making 'Stalemate II' superfluous. A 1,200-ft (365-m) airstrip was constructed on Falalop islet and a hospital and fleet recreation centre were establish on other larger islets. The base was not seen as permanent, so an oil tank farm was not constructed. The US Navy instead maintained a force of six to eight obsolete tankers, each with a capacity of between 8,000 and 11,000 tons, in the anchorage as a floating tank farm. A fleet of 40 oilers then shuttled the oil from Ulithi to the fighting fleet.

On Halsey’s recommendation, the planned US Army seizure of Yap island in the Palau islands by Major General John R. Hodge’s XXIV Corps on 5 October was cancelled as superfluous. The island was garrisoned by Colonel Daihachi Eto’s eight-battalion 49^th Independent Mixed Brigade, totalling 4,000 men, the 3,000-man 46^th Base Force of the Japanese navy, and 1,000 labourers.