History of the Second World War (116 page)

By the time the American submarines were operating from Subic Bay in Luzon, most of Japan’s merchant marine had been eliminated, and good targets became so rare that part of the submarine force was employed in picking up the crews of bombers which had to make forced landings in the sea when returning from air raids on Japan.

In sum, the contribution of the U.S. submarine force was immense, and not least towards stopping Japanese efforts to send troop reinforcements and supplies to the cut-off garrisons overseas. But the greatest effect was in sinking 60 per cent of the 8 million tons of Japanese shipping lost in the war. That was the most important factor in Japan’s final collapse — decisive in the way it exploited her economic weakness and dependence on overseas supplies.

OKINAWA — THE INNER GATEWAY TO JAPAN

The final preparations for the amphibious attack on Okinawa, named ‘Operation Iceberg’, was in progress before the capture of Iwo Jima was complete, and D-day for the landings was timed for April 1 — barely six weeks after the landings on Iwo Jima. It was a large island, the largest of the Ryukyu group, being sixty miles long and averaging eight miles wide — large enough to provide an army and naval base for an invasion of Japan. It lay exactly midway between Formosa and Japan, 340 miles from each, and 360 miles from the coast of China, so that a force established on Okinawa threatened all three objectives, while aircraft based there could dominate the approaches to all three.

The island was rugged and forested except in parts of the south where the airfields lay — and even there the limestone ridges were easy for excavation. It thus had a natural defensive strength. This was greatly increased by the build-up of the garrison, General Ushijima’s 32nd Army, to somewhere around 77,000 combat troops and 20,000 service troops — a total of nearly 100,000 — and an abundance of artillery, light and heavy, well-sited in fortified caves. For the Japanese high command were determined to defend Okinawa with all the force they could provide, and the tactics adopted were an obstinate defence-in-depth of the interior, as on Iwo Jima, without wasting strength in a fight on the beaches where the American warships could pound and pulverise the Japanese troops. But for counter-offensive action Imperial G.H.Q. had conserved and assembled over 2,000 aircraft on airfields in Japan and Formosa, and planned to use Kamikaze tactics on a greater scale than ever before.

The American High Command realised that Okinawa would be a very tough nut to crack, calling for a great superiority of force, and thus involving tremendous logistical problems. It planned to land there the recently formed Tenth Army, under Lieutenant-General Simon B. Buckner, employing five divisions and a total of 116,000 men in the initial landings, with two more for the follow-up, and an eighth in reserve. In all the assault force (of three Marine and four Army divisions) amounted to some 170,000 combat troops and 115,000 service troops, Besides overcoming the powerful Japanese garrison, they would have to control a population of nearly half a million.

In an effort to reduce the counteroffensive air threat, Admiral Mitschef’s fast carrier group carried out a series of raids on Japan (March 18-21) a week before the landing, and shot down some 160 aircraft as well as destroying many on the ground — but at the cost of having three of its carriers
(Wasp, Yorktown
, and
Franklin
) badly damaged by Kamikaze attacks. The following week the B.29 Superfortresses from Guam were diverted from their massive attacks on the Japanese cities to blasting the airfields in Kyushu (the southern main island of Japan). Another important preliminary was the occupation of the Kerama Retto group of islands, fifteen miles west of Okinawa, for use as a forward fleet base and anchorage — an Idea urged by Admiral Kelly Turner. An American division occupied the group on March 27, meeting little opposition, and next day tankers arrived there to bring the roadstead into use. The British Pacific Fleet (two battleships, four carriers, six cruisers, and fifteen destroyers) under Admiral Sir Bruce Fraser, which had arrived on the scene in mid-March, covered the area south-west of Okinawa.

On April 1, which was Easter Sunday, the main landings took place, starting at 8.30 a.m., after an intense three-hour preparatory bombardment from sea and air. That same day, Admiral Turner took command of all forces in Okinawa waters. The landings were made on the western coast in its southern part, where a short advance would cut off the southerly end of the island. They met no opposition at all, and by 11 a.m. the two airfields in the five-mile stretch of the landings were occupied without the enemy even showing themselves — much to the astonishment of the invaders, By evening the American beachhead had been expanded to a width of nine miles, and over 60,000 troops had been put ashore safely. By April 3 they had crossed the island, and next day the beachhead was extended to fifteen miles. It was only after the 4th, when the Americans began driving south, that they began to meet stiffening resistance — from the two-and-a-half Japanese divisions in that southern part of the island.

In the air, however, the Japanese had been active from the start, and from April 6 onward Kamikaze attacks intensified — nearly 700 aircraft, of which half were Kamikaze, being sent to Okinawa on the 6th and 7th. Most of them were shot down, but thirteen American destroyers were sunk or damaged.

April 6 was also marked by the Japanese navy’s most notable ‘suicide’ action, when the giant battleship
Yamato
was despatched to the scene, with a small naval escort — but no air cover, and only sufficient fuel for the outward journey. Its approach was quickly spotted, and kept under constant watch while Mitscher’s carriers were preparing a strike by 280 aircraft. At 12.30 p.m. on the 7th it was violently attacked with torpedoes and bombs, and after two hours’ sustained onslaught it sank, with immense loss of life. Like the
Tirpitz
, it never had a chance to fire its great guns against enemy battleships, and its fate provided further confirmation that the battleship era was past.

The land campaign was more protracted. On April 13 the Japanese in the south of the island began a small counteroffensive, but this was easily repulsed. Meanwhile the 6th Marine Division had been pushing northward easily until it reached the rocky and forest-covered Motobu Peninsula, where it was temporarily held up. But the Japanese force here consisted of only two battalions, and their formidable position was overcome on the 17th by a cleverly planned stratagem. Although scattered groups continued resistance until May 6, the balance was heavily in favour of the Americans, some 2,500 Japanese being killed, on a count of dead bodies, for a Marine loss of less than a tenth of that number. Moreover, a Marine detachment had reached the northern tip of Okinawa on April 13, without opposition. The neighbouring small islands were also captured during this period, with little trouble, except on Ie Shima.

On April 19, General Hodges’s 24th Corps launched an attack, with three Army divisions, on the Japanese positions in the south of Okinawa. But an intense preparatory bombardment — from sea, air, and land — had little effect on the Japanese cave-defences. Gains were slight and casualties large, even after the 1st and 6th Marine Divisions were brought into the front line. At the beginning of May, however, the local Japanese commanders, with characteristic dislike of defensive action, profitable though it had proved, decided to launch a counteroffensive, in conjunction with a fresh wave of Kamikaze attacks. Despite a penetration at one point, they were beaten off with very heavy losses — some 5,000 killed. That somewhat eased the way for the resumed American offensive, on May 10, but the following week its progress was halted by prolonged heavy rains.

During the interval, the Japanese withdrew from the Shuri area, covering Naha, the capital, to positions still further south. Early in June the Americans pressed on despite the mud, and by the middle of the month the Japanese were pushed back into the extreme south of the island. Here their strongly held position along the Yaeju-Dake escarpment was broken on the 17th, largely through the use of flamethrowers. Ushijima and his staff committed suicide, as did many other Japanese, but no less than 7,400 surrendered during the mopping-up phase that followed — a significant change.

The total Japanese loss was estimated as 110,000, including Okinawans recruited into the Japanese Army, while the Americans’ loss was 49,000 (of whom 12,500 were killed) — their heaviest campaign loss of the war in the Pacific.

During the three months’ campaign on Okinawa, the Japanese aircraft made ten massed Kamikaze attacks — which they called ‘Kikusui’ (floating chrysanthemum). These totalled over 1,500 individual Kamikaze attacks, with almost as many similar suicidal attacks by other aircraft. Altogether thirty-four naval craft were sunk, and 368 damaged, mostly by Kamikazes. This painful experience caused much foreboding as to what would happen in an invasion of Japan, and thus contributed to the decision, in July, to use the atomic bomb.

MOPPING-UP — IN THE PACIFIC AND BURMA

The pace of the dual American advance had been greatly accelerated by the adoption of a by-passing strategy — attacking and capturing only the points on either route that were needed as strategic stepping stones to Japan and as means to gain strategic control of the Pacific. But when the forces arrived close to Japan, and were preparing for the final spring, it was considered desirable by the Chiefs of Staff to clear their rear by wiping out the isolated garrisons of the main islands that had been left behind in the by-passing advance. So the penultimate phase of the war saw a wide range of mopping-up operations in different areas. More certainly necessary was the clearance of south-central Burma, following Slim’s swift drive to Rangoon, and before launching South East Asia Command’s projected amphibious move to recapture Singapore and the Dutch East Indies.

BURMA*

* For maps, see pp. 514 and 632.

When Slim reached Rangoon, early in May 1945, there were still some 60,000 Japanese troops in his wake, west of the Salween, and it was important to prevent them escaping eastward into Thailand as well as to stop them causing fresh trouble in the area that had been overrun in Slim’s drive to Rangoon. So part of General Messervy’s 4th Corps was sent back to hold the crossings of the Sittang, and another part to meet Stopford’s 33rd Corps, which was pushing down the Irrawaddy. During May, Stopford succeeded in breaking up two attempts by the remains of Sakurai’s 28th Army from Arakan to cross the Irrawaddy eastward, but many small fragments managed to find their way across, and about 17,000 reached the Pegu Yomas area between the Irrawaddy and the Sittang. A diversionary attack to help them by the remains of Honda’s 33rd Army was a failure, so after mid-July Sakurai’s troops tried to slip through Messervy’s guard-screen by splitting up into numerous little groups, of a few hundred men apiece. But most of these little groups were caught and crushed; less than 6,000 men succeeded in reaching the east bank of the Sittang, then in full flood, and were unfit for further fighting.

NEW GUINEA-NEW BRITAIN-BOUGAINVILLE†

† For maps, see pp. 354 and 614.

In MacArthur’s leap-frogging advance along the north coast of New Guinea, during the first half of 1944, he had by-passed several Japanese garrisons and when the Americans passed on to the Philippines they left behind them the remnants of five enemy divisions. Large numbers of Japanese troops were also left stranded in the islands of New Britain and Bougainville. In a directive of July 12 to General Sir Thomas Blamey, the Australian Commander-in-Chief, MacArthur entrusted responsibility to him, as from the autumn, for ‘the continued neutralisation’ of the remaining Japanese in those areas. Blamey chose to interpret the directive in a more offensively minded way — although he had only four divisions available, of which three were militia, after two Australian Imperial Forces divisions had been earmarked for the Philippines campaign.

The 6th Australian Division was sent to Aitape, and from there was to drive eastward in December and destroy Adachi’s three weak divisions around Wewak (totalling about 35,000 men) — which were under-armed, under-nourished, and disease-ridden, as well as isolated. The 100-mile advance through very difficult country strained the Australian transport system, and the spirit of the troops was damped both by disease and realisation that there was no real strategic need for the operation. Progress was very slow, and Wewak was not captured until May, six months later, while remaining Japanese were still holding out in the interior when the end of the war came in August 1945. The Japanese strength had diminished by a fifth in that time; the Australians had lost barely 1,500 in battle, but their casualties from sickness were over 16,000.

To New Britain, in the Bismarcks, the 5th Australian Division had been sent — and its commander (Major-General A, N. Ramsay) showed more sense. By the time it arrived in November, the Americans had gained control of five-sixths of that big island, but the remainder was held by nearly 70,000 Japanese, mostly concentrated in their long-standing base at Rabaul. After making a short advance to the neck of the island, the Australians were content to patrol this short line — and let the large Japanese garrison ‘wither on the vine’. Thereby it was neutralised at minimum cost, until the end of the war brought its surrender.

Bougainville, at the western end of the Solomons, was the largest island of that group. Thither was sent General Savige’s 2nd Corps, with the 3rd Australian Division and two extra brigades. Here again there was no real need for offensive action, as the Japanese, mostly concentrated around Buin in the south of the island, were amply occupied in growing vegetables and in fishing to eke out their scanty foodstuffs. But Savige launched an offensive early in 1945. This made slow progress, as it stirred up the Japanese to fight hard in defence of their food-producing area, and after six months it was broken off by heavy floods. The Australian troops, as on New Guinea, showed little enthusiasm for what they felt, rightly, was a needless effort.