The victory of Midway transformed the climate of war in the Pacific not only objectively but subjectively. From now on, the reheartened American chiefs of staff recognised, they could go over to the offensive. The question was: along which axis? The ultimate objective was the home islands of Japan, unless Tojo and his government could be brought to concede defeat before invasion became necessary. However, the home islands lay 2000 miles from America’s remaining Pacific bases in Hawaii and Australia, between each of which a formidable chain of Japanese island fortresses interposed to block an American amphibious advance. The ground which had been lost so quickly by unprepared garrisons – or through the absence of any garrison at all – between December 1941 and May 1942 would now have to be recovered step by step at painful cost. Was it better to proceed along the pathway of the great islands of the East Indies or to leap across the stepping-stones of the tiny, isolated atolls of the north Pacific?
Choice of route implied choice of commander and of service. On 30 March 1942 the Joint Chiefs of Staff, General Marshall and Admiral King, had agreed on a division of strategic responsibilities in the Pacific. The new arrangement abolished ABDA and put Nimitz, commander of the Pacific Fleet with headquarters at Hawaii, in charge of the Pacific Ocean Area and MacArthur, commander of army forces in the region with headquarters in Australia, in charge of the South-West Pacific Area. To choose the northern route would be to make Nimitz and the navy paramount – a logical step, since the Pacific had always been the navy’s interest. However, the small Marine Corps was its only military arm, and as yet it lacked the shipping, warships and men to stride across the atolls towards Japan. The army, by contrast, had the men, who were being shipped from the training camps to Australia in growing numbers; while the South-West Pacific Area route, which began close to Australia and proceeded along large islands that yielded at least some of the resources an offensive force required, demanded proportionately smaller shipping resources. To choose it, however, was to make paramount not only the army but its commander too. Although MacArthur had become a hero to the American people for his defence of Bataan, he was not popular with the nation’s admirals. A prima donna among subordinates and a man who brooked no equals, he would, they feared, usurp the direction of strategy by subordinating naval to army operations if the South-West Pacific Area was made the primary zone of the counter-offensive.
Through stormy inter-service negotiations a compromise was reached. The services would take the southern route; but the area would be subdivided to allot part of the theatre to Nimitz and the navy, part to MacArthur and the army, which would have strictly limited call on the navy’s transports, carriers and bombardment fleet. The compromise, agreed on 2 July 1942, consigned Task One, the capture of the island of Guadalcanal, east of New Guinea, to the navy. Task Two, an advance into New Guinea and its offshore island of New Britain, where Japan had a major base at Rabaul, would go to MacArthur; so eventually would Task Three, a final assault on Rabaul.
Guadalcanal, in the Solomons, committed both the United States Navy and the United States Marine Corps to a desperate struggle. Though safely approachable from New Zealand, the departure point of the operation, it was surrounded on three sides by other islands in the Solomons group, which together formed a confined channel that was to become known to the American sailors as ‘the Slot’. Once troops were ashore, the navy was committed to resupplying them through these confined waters and so to risking battle with the Japanese in circumstances where manoeuvre was difficult and surprise all too easy for the enemy to achieve.
The 1st Marine Division, a regular formation of high quality, was landed without difficulty on 7 August and also took the offshore islands of Tulagi, Gavutu and Tanambogo. The Japanese garrison numbered only 2200 and was swiftly overcome. However, the appearance of the Marines on Guadalcanal provoked the Japanese high command to frenzy; ‘success or failure in recapturing Guadalcanal’, a document later captured read, ‘is the fork in the road which leads to victory for them or us.’ Since the Japanese recognised that a breach in their defensive perimeter at Guadalcanal would put the whole of their Southern Area at risk, they resolved on extreme efforts to retake it. On the night of 8/9 August off Savo Island they surprised the American fleet supporting the Guadalcanal landings, sank four cruisers and damaged one cruiser and two destroyers. From 18 August they poured reinforcements into the island, supported by naval guns and aircraft which continuously attacked its airfield (renamed Henderson Field in honour of a Marine pilot killed at Midway). On 24 August a fleet carrying the largest reinforcement yet dispatched was intercepted by the American navy east of Guadalcanal and the second of five battles fought in its waters ensued. This Battle of the Eastern Solomons was an American victory; though Enterprise was damaged, the Japanese lost a carrier, a cruiser and a destroyer and about sixty aircraft to the Americans’ twenty.
Though repelled at sea, the Japanese were fighting furiously on land. The Marines, elite troops though they were, learned on Guadalcanal both the professional respect and ethnic hatred they were to feel for the Japanese throughout the Pacific war. A feature near Henderson Field became a focus of particularly fierce fighting; the Marines called it ‘Bloody Ridge’. The navy meanwhile christened the nightly convoys of Japanese destroyers which ran reinforcements to the island the ‘Tokyo Express’. It made regular efforts to intercept and on the night of 11/12 October caught and surprised a Japanese cruiser force in darkness. In this Battle of Cape Esperance the Americans came off best. However, on 26 October two much larger fleets met again in the Battle of Santa Cruz, south-east of Guadalcanal, and the decision went the other way. The Japanese had four carriers present, and 100 of their aircraft were shot down. Yet though the Americans had only two carriers at risk, and suffered half the total of Japanese aircraft losses, Enterprisewas damaged and Hornet, the heroine of the Doolittle raid on Tokyo, went down.
The epic struggle for Guadalcanal
Before the Battle of Santa Cruz the Japanese had launched a violent offensive against the American defenders of Guadalcanal between 23 and 26 October, days of torrential rain which grounded the American aircraft operating from Henderson Field but allowed Japanese aircraft based elsewhere to deliver a succession of attacks. The Marines held out, counter-attacked and even received reinforcements, though in the teeth of Japanese efforts to close Guadalcanal’s waters to American transports. Between 12 and 15 November, in three days of heavy fighting in ‘the Slot’ now known as the Battle of Guadalcanal, battleships clashed with battleships in the first classic duel of capital ships since Jutland – but on this occasion action was joined at night and radar proved the decisive factor. On the night of 12 November the Japanese flagship Hiei was so badly damaged that next morning she fell victim to aircraft from Enterprise and was sunk. On the night of 14/15 November the battleship Kirishima inflicted forty-two hits on theSouth Dakota; but South Dakota was brand-new and Kirishima old. South Dakota survived, while the Washington sent Kirishima to the bottom with nine 16-inch shell strikes delivered in seven minutes. A fortnight later, in the Battle of Tassafaronga on 30 November, an American cruiser force came off less well, but there, as in the fighting in ‘the Slot’ (also known as ‘Ironbottomed Sound’ from the number of ships sunk there), the Japanese covering force failed to run its troop transports to land. Thousands of Japanese soldiers had drowned in the course of the battles to win command of Guadalcanal’s waters.
Starved of reinforcements and supplies, the Japanese garrison of Guadalcanal now began to falter. The island was plagued by leeches, tropical wasps and malarial mosquitoes, and as rations dwindled the Japanese troops fell prey to disease. The Americans too became ill – pilots at Henderson Field lasted only thirty days before losing the quickness of hand and eye necessary to do battle – but the tide of battle was now running their way. In January 1943 the Japanese commander on Guadalcanal withdrew his headquarters to the neighbouring island of Bougainville. In early February the ‘Tokyo Express’ began to operate in reverse, evacuating the sickly and exhausted defenders to New Guinea. By 9 February Japanese resistance on Guadalcanal had formally ceased.
For the Marines Guadalcanal was remembered as an epic struggle. Men who had fought there bore an aura of endurance which veterans of almost no other Pacific campaign acquired. In terms of casualties it had nevertheless been a comparatively cheap victory. The Japanese had lost 22,000 killed or missing, the 1st and 2nd Marine Divisions, which bore the brunt of the fighting, only a little over a thousand dead. On Guadalcanal the American forces had established the tactical method they would employ across the width of the Pacific to beat the Japanese into subjection. It entailed the commitment of elite landing troops, heavily supported by ground-attack aircraft and naval gunfire, to take and hold key islands at the perimeter of Japan’s area of conquest, as stepping-stones towards the home islands. As conceived and executed, it brought about a contest between morale and material. Both sides were to display supreme bravery; but, while the emperor’s soldiers were ultimately dependent upon their concept of honour in sustaining their resistance, the Americans could call up overwhelming firepower to kill them in thousands. It was an unequal contest which in the long run the Americans were bound to win.
They were about to win another Pacific victory far from the steamy shores of Guadalcanal. In June 1942, in the only successful subsidiary of the Midway offensive, a Japanese force had landed on the two westernmost islands of the Aleutian chain, the American archipelago which runs from Alaska towards Japan. The Americans, preoccupied elsewhere, had let them bide; but in May 1943 Nimitz gathered a force, landed it on Attu and confronted the occupiers. He also sent three battleships in support, since the Japanese had fought a spirited heavy-cruiser action off the islands in March. The occupiers were few in number (2500) but inflicted 1000 dead on their American attackers before running out of ammunition and launching a suicidal bayonet charge. In August an even larger force recaptured Kiska, from which the Japanese prudently withdrew before they were attacked.
On New Guinea, in the equatorial belt, the Japanese had by contrast dug in to stay, in terrain which strongly favoured the defence. They had landed in the Papuan ‘tail’ of the New Guinea ‘bird’ on 22 July 1942, after the American victory in the Battle of the Coral Sea had deflected their effort to pass round it by sea to Port Moresby from north to south. Their attempts to take Port Moresby by an overland advance through the passes of the Owen Stanley range were checked by Australian troops and they were forced to fall back on their landing places at Buna and Gona. When the Australians, with American support, went over to the offensive, however, the Owen Stanley became a barrier to the Allies’ advance, since the only route through the mountains was the tortuous Kokoda Trail. It was with the greatest difficulty that an attacking force was established in position outside Gona and Buna, where the Japanese were deeply entrenched. Fierce and painful fighting ensued throughout November and December 1942. Though the Japanese were starving, the Australians and Americans were disheartened by the appalling conditions in which they had to fight. On 2 December, however, a new general, the American Robert Eichelberger, arrived and revitalised the offensive. By 2 January 1943 Buna had been taken; the Australian 7th and US 32nd Divisions had meanwhile captured Gona, which fell on 9 December. The casualties were again grossly to the disadvantage of the Japanese: they lost 12,000 dead in the campaign, the Allies 2850, mostly Australians.
Victory in Papua, though it left the Japanese with footholds in the rest of New Guinea, ended the threat to Australia and cleared the way for MacArthur to concentrate his efforts on breaking back along the southern route towards the Philippines through the Solomon and Bismarck archipelagos. His strategic concept, however, even though it entailed much ‘island-hopping’ – an essential by-product of which was to seize airstrips from which to establish overlapping zones of air control – which would leave bypassed Japanese garrisons to ‘wither on the vine’, included so many landing operations that its demands for men, ships and particularly aircraft threatened to exhaust the resources available. His ultimate objective was Rabaul, Japan’s strong place d’armes in New Britain, the largest island of the Bismarck group; but his programme of advance would require five extra divisions and forty-five additional air groups, or about 1800 aircraft. As was pointed out at the Casablanca conference of January 1943, at that time there were already 460,000 American troops in the Pacific but only 380,000 in the European theatre, where preparations for the Second Front had already begun with the invasion of North Africa. MacArthur’s demands provoked a severe inter-service dispute in Washington which lasted until March 1943. While the Japanese were locked in combat with the American and Australian soldiers and Marines in Guadalcanal and New Guinea, army and air force generals and admirals pitted the interests of their rival services over a decision about the development of the Pacific war. At the end of April 1943 a plan finally emerged. It was codenamed Cartwheel and, though it preserved the spirit of the agreement of 2 July 1942, it included a significant modification. Nimitz was now made theatre commander for the whole Pacific, and, while MacArthur was left in charge of the South-West Pacific Area, Admiral William Halsey was entrusted with operations in the South Pacific which would include an advance on MacArthur’s flank. In short, MacArthur was to envelop Rabaul from the south, Halsey from the north. New Guinea and the southern Bismarcks were to be the former’s responsibility, the Solomons the latter’s. Once MacArthur had taken the north shore of New Guinea and the hinterland of New Britain, on which Rabaul stood, and Halsey had advanced along the Solomons chain to Bougainville, they would descend on Rabaul by pincer movement.
While the Joint Chiefs of Staff and their service subordinates were conducting this Pacific Military Conference in Washington, the Japanese, acutely aware that they had been forced on to the strategic defensive in the southern Pacific, were busy reinforcing and reorganising their garrisons there to withstand the expected assault. The overall commander was General Hitoshi Imamura, whose headquarters were at Rabaul; under his command was the Seventeenth Army in the Solomons. Imperial headquarters now decided to add to this a new army, the Eighteenth, to defend northern New Guinea. General Hatazo Adachi, commanding the Eighteenth Army, brought two new divisions from Korea and north China. Landing first at Rabaul, one of the divisions, the 51st, with Adachi’s headquarters, then took ship for its new station at Lae in New Guinea. En route it was intercepted by American aircraft, which inflicted on it the first of two spectacular aerial successes achieved that spring.
In August 1942, MacArthur had been given a new air commander, General George Kenney, who had wrought a revolution in the USAAF’s anti-ship tactics. Previously, though army pilots had reported numerous successes against the Japanese navy, after-action analysis had revealed that they had hit very few targets at all. Kenney transformed their methods. Recognising that the USAAF’s chosen method of precision bombing from high altitude lay at the root of the failure, he trained his medium-range bomber pilots to attack at low level with guns and fragmentation bombs. When the 51st Division left Rabaul for Lae on 2 March 1943 it was first intercepted by Flying Fortresses employing the old high-level technique, which sank only one ship. Next day, however, a hundred medium-range B-25s, A-20s and Australian Beaufighters found it again, skimmed in at sea level, escaped the attention of the Zeros patrolling at high altitude to deal with the expected Fortresses and sank all the transports and four of the eight destroyer escorts.
The Battle of the Bismarck Sea was a significant material victory. Next month MacArthur’s air force achieved a psychological victory of perhaps even greater importance. A recent addition to its strength was the long-range, twin-engined Lightning fighter, the P-38. Since it was no match for the Zero in dogfighting, the Lightning was chiefly reserved for strategic strikes against major formations of Japanese aircraft, diving against them from a high altitude. The P-38 became an object of terror and loathing, and the sound of its engines soon became familiar to Japanese airmen in the South Pacific. In an effort to reverse the success that the Lightnings and B-25s were achieving, Yamamoto assembled the largest available force of his own aircraft and committed them against Guadalcanal and its offshore island of Tulagi in early April 1943. This ‘I-Go’ operation, flown in early April, failed in its object, which was to sink as much shipping as possible, but the pilots reported differently. Like the American Flying Fortress pilots previously, they believed they had sunk ships which had in fact not been touched except by the waterspouts of their bombs. Yamamoto was nevertheless convinced and decided to visit his men to encourage them to further efforts.
Imprudently, notice of his intended arrival was circulated to the Eighth Area Army from Rabaul by cipher, which the American cryptographers at Pearl Harbor quickly broke. Nimitz decided to ‘try to get him’. A squadron of Lightnings was hastily equipped with drop-tanks, to give them the extra range a successful ambush flight required, and on the morning of 18 April, as Yamamoto approached the airfield of Kahili in Bougainville, his aircraft was destroyed with a burst of 20 mm cannon fire and fell burning into the jungle.
Yamamoto’s ashes were buried in Tokyo on 5 June. Later in the month began the great dual drive up the Solomons and New Guinea towards Rabaul which it had been one of the purposes of the ‘I-Go’ operation to check. At the end of June, Woodlark and the other Trobriand islands – the latter the focus of a famous ethnographic inquiry among its primitive inhabitants – were captured, thus securing the seaward approaches to the ‘tail’ of the New Guinea ‘bird’. In June also an amphibious hook was made towards Lae on the northern New Guinea coast; it fell on 16 September and the Americans then moved on via Finschhafen to seize Saidor, opposite Cape Gloucester on New Britain, which they assaulted on 26 December 1943; a subsidiary landing was made on New Britain at Arawe, closer to Rabaul, on 15 December.
Meanwhile Halsey had been keeping pace with MacArthur in his own advance along the Solomons chain. The Russell islands next to Guadalcanal had been taken in February, the New Georgia group in June and July and Vella Lavella in August. The Japanese attempted both land and sea counter-offensives at New Georgia and Vella Lavella but were unsuccessful. By October 1943 Halsey was ready to assault Bougainville, the westernmost and largest of the islands in the Solomons, and only 200 miles from Rabaul at the narrowest sea crossing. The landings were preceded by a fierce but unsuccessful air battle to check the American advance; the plan, codenamed ‘RO’ by the Japanese, was devised by Admiral Mineichi Koga, who had succeeded Yamamoto as commander of the Combined Fleet. As soon as the battle was over, Halsey launched an amphibious assault on the small Treasury Islands off Bougainville’s southern coast on 27 October and then a main assault at Empress Augusta Bay on 1 November. Koga sent a strong force of two heavy and two light cruisers to oppose the landings – hoping, as off Savo Island in the Battle of Guadalcanal, to inflict damage on the American fleet – and twice forced Halsey to risk unsupported carriers against them. However, the gamble paid off; the Japanese lost heavily in aircraft (fifty-five to the Americans’ twelve) and suffered damage to three of their cruisers. By 21 November, the 3rd Marine and 37th Divisions were firmly established on Bougainville; from there, in conjunction with MacArthur’s advance up New Guinea, the pincers now threatened to close about Rabaul.
The threat to Rabaul opened up the prospect of a seaborne advance along the northern shore of New Guinea from which MacArthur’s and Halsey’s forces might leap towards the East Indian islands of the Moluccas and so towards the Philippines. Even as the trap began to close about Rabaul, however, the character of the war in the Pacific was taking another turn. At the Casablanca conference in January 1943 Roosevelt, Churchill and the Combined Chiefs of Staff had given assent to the American navy’s cherished plan, proposed by the Chief of Naval Operations, Admiral King, for an advance towards the Philippines through the central Pacific to assault the Caroline and Marshall Islands. The decision of 2 July 1942, which had allotted naval support to MacArthur for his drive towards Rabaul, had been taken when the United States Navy was still painfully rebuilding its resources after the losses suffered at Pearl Harbor and in the victories of the Coral Sea and Midway. Then there had been few carriers and no battleships. By the beginning of 1943 American shipyards had begun to make good the gaps; by mid-1943 new battleships – essential for ship-to-shore bombardment in preparation and support of amphibious landings and to provide heavy anti-aircraft support for the carriers – and new carriers, of both the fleet and light classes, had arrived or were promised in plenty. The Anglo-American Washington conference in May 1943 had agreed that, as long as the forthcoming invasion of Europe was the first charge on the now rapidly expanding output of Allied war material, the offensive against Japan could be extended. On 20 July, therefore, enlarging on the spirit of that decision, the Joint Chiefs of Staff authorised Nimitz to prepare a landing operation against Japanese conquests in the Gilberts and to plan for subsequent landings in the Marshalls.
These were dramatic prospects. MacArthur’s and Halsey’s campaign in the south Pacific, though amphibious in character, was in essence a traditional land-sea advance. Navy supported army, and vice versa, in a series of leaps comparatively short in span. The longest leap that MacArthur had so far taken was 150 miles between Buna and Salamua, the longest by Halsey 100 miles from Guadalcanal to New Georgia. Distances in the central Pacific, by contrast, were of a different order. Between Tarawa in the Gilberts and Luzon, the main island of the Philippines, stretched 2000 miles of sea. It was not entirely empty: the atolls of the central Pacific number over a thousand. However, while MacArthur’s and Halsey’s islands were great platforms of dry land, New Guinea being almost as large as Alaska and twice the size of France, the Pacific atolls were mere spits of sand and shelves of coral surrounding a lagoon and bearing a few palm groves which barely found roots above high-water mark. There had been many campaigns like MacArthur’s in previous centuries, notably in the Mediterranean and in Japan’s own inland sea. There had never been a campaign such as Nimitz now contemplated – a giant’s leap between stepping-stones so separated that they would stretch the United States Navy to breaking-point.
What made the central Pacific offensive a feasible undertaking was the transformation the Pacific Fleet had undergone in the two years since the catastrophe at Pearl Harbor. It was no longer a ‘battle-wagon’ navy, a Jutland-style train of slow, old, heavy-gun platforms dedicated to finding and fighting the enemy in battering duels at 20,000 yards. Even its battleships were new, faster and stronger by far than those which still lay on the bottom of Pearl Harbor or those which had been raised and refurbished from it. Its carriers, which now formed its cutting edge, were a new breed of ship: the light carriers of the Independence class, converted from fast cruisers, embarked fifty aircraft and could manoeuvre at over 30 knots; the new Essex-class fleet carriers were equally fast, embarked a hundred aircraft and were heavily armed with 5-inch and 40- and 20-mm anti-aircraft guns. By October 1943 there were six Essex-class carriers at Pearl Harbor, ready to lead Nimitz’s Pacific Fleet into battle; they were to form ‘fast carrier task forces’, which would protect the newly built fast ‘attack transports’ and their destroyer, cruiser and battleship escorts in nine atoll landings on the approach to the Philippines.
First of the atolls to be taken under attack were Makin and Tarawa in the Gilberts, British islands lying at the extreme edge of Japan’s defensive perimeter. Makin, lightly garrisoned by the Japanese, fell quickly when Admiral Charles Pownall’s Task Force 30 landed Marines and army units on 21 November 1943. Tarawa was a different matter. More heavily garrisoned (by 5000 Japanese), it was also surrounded by a high reef over which the new Marine amphibious armoured vehicles (amphtracs) passed easily but on which the landing craft in which most of the assault force were embarked stuck. The Marines suffered very heavy casualties getting ashore on 21 November and then found themselves pinned beneath beach obstacles which offered the only cover. Some 5000 men landed; by nightfall 500 were dead and 1000 wounded. Even direct hits from battleship guns failed to destroy the Japanese strongpoints, whose defenders ceased resistance only when killed. It was not until the following day, when a second force landed with tanks on an undefended beach and attacked from the rear, that headway was made – but in barbaric circumstances. Tarawa was the battle which taught the Marine Corps how ferocious the struggle even for the smallest Japanese-held island could be. Robert Sherrod, a war correspondent, recorded:
A Marine jumped over the seawall and began throwing blocks of TNT into a coconut-log pillbox. Two more Marines scaled the seawall [with a flamethrower]. As another charge of TNT boomed inside the pillbox, causing smoke and dust to billow out, a khaki-clad figure ran out from the side entrance. The flame thrower, waiting for him, caught him in its withering flame of intense fire. As soon as it touched him the Jap flared up like a piece of celluloid. He was dead instantly but the bullets in his cartridge belt exploded for a full sixty seconds after he had been charred almost to nothingness.
Despite such evidence of the Marines’ material superiority – or perhaps, in desperation, because of it – during the night the Japanese made a ‘death charge’, as they had done on the Aleutians, and ran on to the American guns; next morning the bodies of 325 were found in an area a few hundred yards square. At noon the battle was over: 1000 Marines were dead and 2000 wounded; almost all the Japanese had perished. To spare their men such horrors in the next fight, commanders initiated a crash building programme of amphtracs, earmarked naval vessels to act as specialised command ships to control air and sea bombardment and co-ordinate it with the landings, and had exact copies of the Tarawa defences built so that instructors could practise against them and train Marines in the best methods of overcoming them.
Tarawa had another immediate and positive effect on the development of the central Pacific campaign. Because the Japanese fleet had not intervened or even shown its face in the area, and because Japanese land-based aircraft from other islands had also not interfered, Nimitz concluded that it would be safe to leave the garrisons of the other Marshalls to ‘wither on the vine’ and press forward to the westernmost in the group, Kwajalein and Eniwetok. Kwajalein was so heavily pounded by ships and aircraft before the Marines landed on 1 February 1944 that they secured its northern islets in two days, and the army’s 7th Division took the southern atoll in four days, neither incurring heavy loss. As a preliminary to the invasion of Eniwetok and to complete the neutralisation of Japanese airpower in the region, Nimitz decided to launch Task Force 58 against the more remote atoll of Truk, a forward anchorage of the Japanese Combined Fleet, with room to accommodate up to 400 aircraft. Task Force 58 was really four separate task forces, each with three carriers which between them embarked 650 aircraft. In a high-speed assault on Truk on 17-18 February, its commander, Vice-Admiral Marc Mitscher, mounted thirty raids, each more powerful than either of the Japanese strikes on Pearl Harbor, destroyed 275 aircraft and left 39 merchantmen and warships sinking. The raid established Mitscher’s reputation as the master of fast carrier operations. It also ensured that Eniwetok fell by 21 February, though it took five days of fighting to overcome the suicidal Japanese defence.
The fall of the Marshalls opened the way to the Marianas, among which the large islands of Saipan and Guam were obvious landing places. Nimitz was in a hurry. Far to the south, in New Guinea, MacArthur was accelerating the pace of his advance. At the Anglo-American Quebec conference in August 1943 it was agreed that the projected pace of progress towards the Philippines was too slow, that Rabaul was not to be attacked but to be neutralised by air attack, and that MacArthur should advance along the northern coast of New Guinea by a series of amphibious hooks. The Cairo conference in November, which specifically approved Nimitz’s offensive into the Marshalls, appeared to MacArthur to downgrade his campaign. When his staff reported in February that they believed Rabaul could be left far to the rear by a descent north of New Guinea on the Admiralty Islands, which appeared largely undefended, he leapt at the chance. Between 29 February and 18 March 1944 the islands were secured and MacArthur at once decided to make his longest leap yet – 580 miles – to Hollandia, halfway along New Guinea’s north coast. There the Japanese, when surprised on 22 April, uncharacteristically fled in panic. Thence MacArthur drove forward throughout May, to Wakde and Biak off the north-west coast of New Guinea. The Japanese fought so hard for Biak that the battle was still in progress at the end of June and it was not until the following month that MacArthur could complete his strategic programme and, on 30 July, seize the Vogelkop peninsula, in the ‘head’ of the New Guinea ‘bird’, as a departure-point for his return to the Philippines.
The intensification of MacArthur’s offensive in the south had an unintended, indirect but crucial effect on the conduct of the central Pacific campaign. So alarmed were the Japanese by the landing at Biak that they determined to call a halt to it by concentrating the Combined Fleet in East Indies waters to recapture the island; at the end of May its ships, including the new giant battleships Yamato and Musashi, were already at sea. Then clear evidence that Nimitz was preparing to spring forward from the Marshalls to the Marianas and approach the Philippines obliged the Japanese to cancel the operation, and the Combined Fleet prepared to move to the central Pacific to fight a decisive battle in great waters.
Before it could arrive, Nimitz’s Marines and the army’s 27th Division had debarked at Saipan in the Marianas. Saipan was a large island with a garrison of 32,000 men; the American operation against it was proportionately large also. Seven battleships fired 2400 16-inch shells into the landing zone before the troops touched down on 15 June, and eight older battleships kept up the bombardment during the landing, strongly supported by aircraft. Over 20,000 American troops were put ashore on the first day, by far the largest force yet delivered in a Pacific amphibious operation, and equivalent in size to those debarked in 1943 in the Mediterranean. However, the Japanese defenders resisted fiercely and meanwhile the First Mobile Fleet – the carrier element of the Combined Fleet – was approaching to deliver its strike against Task Force 58. Fortunately the American submarine Flying Fish, on patrol off the Philippines, saw it clearing the San Bernardino strait and gave Mitscher warning. He at once turned to the attack, with fifteen carriers against nine, and prepared to mount an aerial offensive. In the event the Japanese established Mitscher’s position before he did theirs; but because of the superiority of his radar, fighter control and now aircraft – the new Hellcat was faster and better armed than the Zero – all four of Admiral Jisaburo Ozawa’s attacks failed, either in dogfighting above the carriers or against the guns of the ships. When this ‘Great Marianas Turkey Shoot’ was over on the evening of 19 June, 243 out of 373 Japanese aircraft had been shot down, for the loss of 29 American; and in the course of the action American submarines torpedoed and sank the veteran Shokaku and the new Taiho, Ozawa’s flagship and the largest carrier in the Japanese navy.
This was not the end of the affair. Next day Task Force 58 found the First Mobile Fleet refuelling, sank the carrier Hiyo with bombs and damaged two others and two heavy cruisers. The Battle of the Philippine Sea, as the two days of action were called by the Americans (the Japanese named it the ‘A-Go’ offensive), therefore halved the operational strength of the Japanese carrier force, reduced its aircraft strength by two-thirds – perhaps an even more damaging blow, since pilots emerged very slowly from the Japanese training system – and left Task Force 58 almost intact.
Disaster at sea for the Japanese was followed by disaster on land. After a bitter fight on Saipan, the defenders began to run out of ammunition and chose suicide rather than surrender; among the Japanese on the island were 22,000 civilians, of whom a large number are alleged to have joined the survivors of the 30,000 combatants in killing themselves rather than capitulate. Saipan was declared secured on 9 July. The neighbouring island of Tinian, where resistance was much lighter, fell on 1 August and Guam, whose garrison was battered into defeat despite its desperate resistance by an overwhelming American bombardment, on 11 August. All the territory that the Americans then coveted in the Marianas was theirs. From it their new bomber, the B-29 Superfortress, would be able to reach out to attack the home islands directly. Even more important, from the Marianas the Pacific Fleet could begin preparing the assault on the northern islands of the Philippines, whose southern islands were also threatened by MacArthur’s advance on the East Indies.