After the American victories at Midway and Guadalcanal, the tides of war in the Pacific turned against Japan. Due to America’s overwhelming military and industrial capabilities, the Allied forces gained the upper hand. Over the next two years the Japanese suffered a series of military setbacks, losing many of the islands they had conquered. The Allied military leaders often adopted a policy of ‘island hopping’, bypassing Japanese strongholds that had a strong presence, but were isolated and could not be reinforced. This strategy was adopted so that the Allied soldiers could be rested for the islands that the Japanese could reinforce.
At the January 1943 Casablanca summit conference, the Western Allied leaderships reasserted the priority of defeating Germany, but agreed to devote sufficient resources to the war against Japan to maintain the initiative. The US Navy and Marine Corps were unfailingly sceptical about southwest Pacific operations, directed towards ultimate recapture of the Philippines. The admirals preferred instead to thrust across the central Pacific through the Marshall, Caroline and Mariana islands, the shortest route to Japan. A decision was taken to undertake both simultaneously. The British, meanwhile, addressed themselves once more to Burma.
The expansion of the US Navy made possible a growing Pacific buildup in the course of 1943. Four huge Essex-class fleet carriers and five light carriers provided the core of fast task forces which included battleships and cruisers for shore bombardment, destroyers for radar picket and anti-submarine escort duties. A vast fleet train of oilers and supply vessels enabled the fighting ships to sustain up to seventy days of continuous operations, far beyond the Royal Navy’s capabilities. There were also escort carriers to provide close support for the amphibious armadas, and hundreds of PT-boats for inshore work, together with repair and hospital vessels.
Japanese strategy, such as it was, required extraction of the highest possible blood-price from the Americans for every small gain, to erode their will and persuade them to negotiate. It is often claimed that Japan’s militarists alone insisted on continuing the war, but the generals enjoyed powerful support from conservative politicians, many fervent Japanese nationalists, and from the Emperor.
Cultural revulsion underpinned the hatred which characterized Allied conduct of the Asian war. Japan’s savagery towards its prisoners and subjects was now well known, and often repaid in kind. Japanese willingness to fight to the death rather than surrender, even in tactically and indeed strategically hopeless circumstances, disgusted Allied troops. The Japanese, who had been merciless in victory, now showed themselves determined to cull every possible human life from their inexorable descent towards defeat.
In the Pacific, until massive resources reached the theater during 1944, there were long pauses between successive American initiatives. In June 1943, General Douglas MacArthur and South-West Pacific Area Commander Admiral William Halsey began their new campaigns in New Guinea and the Solomons. The seizure of New Georgia took a month of tough fighting. Thereafter, Halsey leapfrogged several Japanese-defended islands to land 4,600 men on Vella Lavella. By January 1944 a major air offensive against Rabaul had rendered the base almost useless to Japanese ships and aircraft.
MacArthur held a grand title, and had been exalted by propaganda into the most famous of American warlords. His public-relations machine was the most effective branch of his headquarters. The Pacific War’s Supreme Commander had a physical presence, strength of will and personal authority greater than those of the US chiefs of staff. Although MacArthur was never given the massive resources he demanded, he exercised a political and moral influence which sufficed to sustain his campaign and enable him to pursue his chosen personal objectives.
The Japanese not only hoped — and failed — to hold their perimeter in the south; they had decided to hold in the north as well. An effort to reinforce the garrison in the Aleutians failed, and the landing forces there faced as best they could an American determination to retake the islands. American troops landed on Attu, bypassing and thus effectively isolating Kiska. In bitter fighting the Japanese force on Attu was destroyed. The Japanese thereupon decided to evacuate their garrison from Kiska, a project they successfully pulled off without the knowledge of the Americans, whose big landing force was as astonished as it was relieved to find the Japanese gone.
Having seized the Russell Islands between Guadalcanal and New Georgia, the Americans now launched a coordinated offensive against New Georgia. The island of Rendova just across a narrow strait from Munda was the scene of a landing; three days later the Americans landed on New Georgia itself. The land fighting was longer and more costly than the Americans had anticipated; but after reinforcements were sent in and the American division commander replaced, a series of drives brought the Americans control of the Munda airfield and then of the rest of New Georgia.
The next island in the Solomons was Kolombangara, even more heavily garrisoned and fortified than New Georgia. Taking a leaf from Admiral Thomas C. Kincaid's procedure in the Aleutians, where Kiska had been bypassed for an assault on Attu, Admiral William Halsey now made an almost unopposed landing on Vella Lavella, the large island on the other side of Kolombangara from New Georgia. This jump left the Japanese garrison of 10,000 men to sit on their island while the war passed them by after they had failed to dislodge the Americans from Vella Lavella.
The Americans, and the Australian and New Zealand contingents fighting alongside them, could now prepare for the attack on the most important island in the northern Solomons, Bougainville, where they would be on the other side of Rabaul from the Australians and Americans at Finschhafen on New Guinea. Attacks by planes and warships on the Japanese air bases at both ends of the island threw off the defenders, who were totally surprised by the 3rd Marine Division's landing. The fighting continued for months; but without substantial air support and with no prospect of reinforcement, the Japanese soldiers on the island became involuntary bystanders in the war.
Nimitz’s central Pacific offensive opened in November 1943, with landings on the tiny atoll of Tarawa in the Gilbert Islands. US forces wrecked every local Japanese airfield with bombs and gunfire before the landings. Yet the experience that followed proved one of the most bitter of the US Marine Corps’ war. On Betio, the main islet, less than two miles long and seven hundred yards wide, the Japanese had created bunkers of concrete, steel and felled palm trees which were almost impervious to bombs and shells. Four days of fighting followed, among blasted palm trees and skilfully camouflaged defenses. When the shooting stopped, the Marines had suffered 3,407 casualties and almost all the Japanese defenders were dead – just 17 POW’s were taken.
The initial attack on the Tarawa coral atoll had been on Betio, the main island of under 300 acres with the airport. The other islands in the atoll were taken quickly after Betio was secured, while an army division was able to seize the lightly defended island of Makin. Landing a regimental task force of 6,500 soldiers of all arms, the division took three days to defeat a mere 400 defenders, albeit at a light cost of 200-plus casualties.
With hindsight, it is clear that the United States could have halted its ground operations against Japan in 1944, once the Marianas were secured. From its air bases, the USAAF’s Superfortress bombers could reduce the enemy’s homeland to ashes. Together with the naval blockade, which crippled Japanese industry and above all oil supplies, irresistible air bombardment made eventual Japanese capitulation inevitable. But this is a perspective accessible only to posterity. At the time, it would have seemed unthinkable to halt ground operations.
Once US planes could operate from Tarawa, they swiftly destroyed Japanese air capability throughout the Marshall Islands. The Marines were pleasantly surprised by the ease with which they captured Majuro, Kwajalein and Roi-Namur atolls, a personal triumph for Nimitz, who overruled all his subordinates to insist upon attacking the central Marshalls, rather than the heavily defended easternmost islands. They then took Eniwetok, at the extreme north-western end of the Marshall chain, while Spruance’s carrier aircraft devastated the key Japanese base at Truk in the Carolines.
To protect the Marshalls operation, a major air assault was launched against the Japanese base of Truk. The Imperial navy, it turned out, had already abandoned Truk for the safer Palau islands, but the destruction of planes, ships and installation left a shambles of the ‘Gibraltar of the Pacific’. The disaster of Truk was the last straw for the Japanese Prime minister, General Hideki Tojo; he had the navy Chief of Staff, Admiral Chūichi Nagumo, sacked and replaced by Navy Minister Shigetarō Shimada while Tojo himself took over as Chief of Staff of the Japanese army.
During 1944, the US Navy gained overwhelming dominance of the Pacific. Blockade rendered inevitable the collapse of an enemy wholly dependent on imported fuel and raw materials; American submarines achieved the strangulation of Japanese commerce which Germany’s U-boats had failed to impose on Britain. Seldom in history has such a small force – 16,000 men – gained such decisive results. In the spring of 1944, it was taken for granted that Allied forces must attack the Japanese wherever possible.
It is extraordinary that Hirohito’s nation went to war knowing the importance and vulnerability of its merchant shipping, yet without seriously addressing convoy protection; the Tokyo regime built huge warships for the Combined Fleet, but grossly inadequate numbers of escorts. Japanese island garrisons found themselves isolated, immobilized and starving. American air and naval dominance denied Japan any chance of launching an effective strategic counterstroke. Its soldiers still enjoyed many opportunities to die bravely, but the nation’s fate was sealed.
Service in the Pacific was an experience light years away from that of Europe, first because of its geographical isolation. Men obliged to exist for months under open skies in tropical conditions suffered relentlessly from disease and skin disorders, even before enemy action took a bloodier toll. Amphibious operations became a Pacific routine, albeit a hazardous and challenging one.
The ultimate fate of Japan’s war effort in 1944 depended on the naval campaign underway in the Pacific. The surface fleets and carrier task forces had avoided one another for much of 1943. But with the Seventh Fleet escorting MacArthur’s land forces westward and the Fifth Fleet charting a new course across the Central Pacific, the US Navy now held the strategic initiative. The submarine force of the Pacific Fleet had no trouble closing with the enemy. Its operations weakened the defenses of the Philippines and the Marianas as well as accelerating Japan’s economic decline.
Allied aerial attacks did not contribute to Japan’s economic attrition until 1945. While the submarine force reduced the raw materials and food for Japan’s industrial society, the US Army Air Forces planned to destroy the cities themselves, not just starve the workers and their families. The future of the air war with Japan rested on the development and rapid deployment of the air force’s most expensive and risky project, the B-29 Superfortress. By mid-1944 the army air forces had taken delivery of fewer than 100 B-29s, but General Henry Arnold wanted even this paltry number in action immediately.
The most important Pacific operation of 1944 was the seizure of the Marianas, key to the inner ring of Japan’s defenses. When the US Marine Corps began its assaults on the islands, the Japanese Combined Fleet sailed to meet the invaders, precipitating the greatest carrier encounter of the war. The Japanese hoped to use submarines and land-based aircraft to severely weaken the Americans before the main engagement. Instead, seventeen of twenty-five Japanese submarines were sunk, while their airfields on Guam and Tinian were devastated by US bombing. What followed became known as ‘the great Marianas turkey-shoot’: of 373 planes dispatched, only 130 survived, having failed to inflict significant damage on the US fleet.
The Japanese defenders of the Marianas faced the same challenge as their dead comrades in the Marshalls, which was to make the American landing forces pay a high price for their new aggressiveness. In this case, they had a solid mission: keep the island airfields in Japanese hands as long as they could use them. Saipan had substantial naval personnel ashore—6,000 officers and men commanded by Vice Admiral Nagumo Chuichi. The Marianas’ defenses, air and ground, depended on the Thirty-First Army under Lieutenant General Obata Hideyoshi, a ground combat force of 59,000 divided among three islands.
Victory at sea off the Marianas could not avert bloody fighting ashore. The Marines’ first objective was Saipan; its fourteen-mile length, and some high ground, enabled the Japanese to deploy 32,000 defenders in depth. When 77,000 US Marines waded ashore they met machine-gun and artillery fire which inflicted 4,000 casualties in the first forty-eight hours. The planners had anticipated a three-day battle, but the island’s capture took three weeks: the defenders had to be blasted from their bunkers yard by yard.
After Saipan the Americans began landing on Guam, a larger island, and a vital objective because it had the only good water supply in the Marianas chain, as well as the best harbor. The protracted resistance on Saipan had given the 19,000-strong Japanese garrison time to construct strong beach defenses, but the Americans preceded the assault with one of the longest and most effective air and naval bombardments of the campaign. This wreaked havoc: organized resistance soon collapsed, though three weeks’ fighting was needed to suppress isolated strong points. In the end the Marines managed to secure the island. However, infantrymen were obliged to maintain patrols and to skirmish with small groups of Japanese on Guam until the end of the war.
The Marines attacked their third Marianas objective, the smaller island of Tinian. Lt. Gen. Holland Smith, commanding the assault, considered this the best-executed amphibious landing of the campaign. Organized opposition was eliminated in twelve days, though once again Japanese survivors refused to surrender.
The most dramatic political repercussion of the Pacific fighting culminating in the American victory in the Marianas was the resulting crisis in Tokyo. The Japanese army's victory over Chiang Kai-shek in China could not offset defeats in India, in New Guinea, and on and near the Marianas, the last being an area Japan had held long before the war. The tough-minded general tried hard to hold on to power, but he could not do so. The palace and most leading political and some military figures combined to assure his being dropped from all of his posts; he resigned.
Informed Japanese knew that their home islands now faced an ordeal by air bombardment; the Marianas airfields brought Japan’s cities within range of US bombers. The shore battles showed that Japanese soldiers’ willingness for sacrifice could extract a high price for each American victory, but the invaders’ firepower was irresistible. However, the Japanese government remained committed to fight on: the supremely stubborn military men who dominated Tokyo’s polity believed they could still achieve a negotiated settlement by convincing the Americans that the cost of assaulting the Japanese homeland would be unacceptably high.