Previous part about Asia-Pacific War: https://forum.vite.net/topic/1376/vite-history-channel-part-15-ww2-asia-pacific-war-second-sino-japanese-war-part-1
New Guinea and the Solomons
Japanese land forces continued to advance in the Solomon Islands and New Guinea. From July 1942, a few Australian reserve battalions, many of them very young and untrained, fought a stubborn rearguard action in New Guinea, against a Japanese advance along the Kokoda Track, towards Port Moresby, over the rugged Owen Stanley Ranges. The militia, worn out and severely depleted by casualties, were relieved in late August by regular troops from the Second Australian Imperial Force, returning from action in the Mediterranean theater. In early September 1942 Japanese marines attacked a strategic Royal Australian Air Force base at Milne Bay, near the eastern tip of New Guinea. They were beaten back by Allied forces (primarily Australian Army infantry battalions and Royal Australian Air Force squadrons, with US engineers in support), the first defeat of the war for Japanese forces on land.
Japanese control of the western Pacific area between May and August 1942. Guadalcanal is located in the lower right center of the map
At the same time as major battles raged in New Guinea, Allied forces became aware of a Japanese airfield under construction at Guadalcanal through coastwatchers. On August 7, US Marines landed on the islands of Guadalcanal and Tulagi in the Solomons. Vice Admiral Gunichi Mikawa, commander of the newly formed Eighth Fleet at Rabaul, reacted quickly. Gathering five heavy cruisers, two light cruisers, and a destroyer, sailed to engage the Allied force off the coast of Guadalcanal. On the night of August 8–9, Mikawa's quick response resulted in the Battle of Savo Island, a brilliant Japanese victory during which four Allied heavy cruisers were sunk. No Japanese ships were lost, it was one of the worst Allied naval defeats of the war.
The victory was only mitigated by the failure of the Japanese to attack the vulnerable transports. Had it been done so, the first American counterattack in the Pacific could have been stopped. The Japanese originally perceived the American landings as nothing more than a reconnaissance in force.
With Japanese and Allied forces occupying various parts of the island, over the following six months both sides poured resources into an escalating battle of attrition on land, at sea, and in the sky. US air cover based at Henderson Field ensured American control of the waters around Guadalcanal during day time, while superior night-fighting capabilities of the Imperial Japanese Navy gave the Japanese the upper hand at night. In August, Japanese and US carrier forces engaged in an indecisive clash known as the Battle of the Eastern Solomons. In October, US cruiser and destroyer forces successfully challenged the Japanese in night-time fighting during the Battle of Cape Esperance, sinking one Japanese cruiser and one destroyer for the loss of one destroyer. During the night of October 13, two Japanese fast battleships Kongo and Haruna bombarded Henderson Field. The airfield was temporarily disabled but quickly returned to service. In October 26, Japanese carriers Shokaku and Zuikaku sank USS Hornet and heavily damaged USS Enterprise in the Battle of the Santa Cruz Islands. The loss of Hornet, coupled with the earlier loss of USS Wasp to the IJN submarine I-19 in September, meant that US carrier strength in the region was reduced to a single ship, the Enterprise. However, the two IJN carriers had suffered severe losses in aircraft and pilots as well and had to retire to home waters for repair and replenishment. From November 12 to November 15, Japanese and American surface ships engaged in fierce night actions in the Naval Battle of Guadalcanal, one of the only two battles in the Pacific War during which battleships fought each other, that saw two US admirals killed in action and two Japanese battleships sunk.
During the campaign, most of the Japanese aircraft based in the South Pacific were redeployed to the defense of Guadalcanal. Many were lost in numerous engagements with the Allied air forces based at Henderson Field as well as carrier based aircraft. Meanwhile, Japanese ground forces launched repeated attacks on heavily defended US positions around Henderson Field, in which they suffered appalling casualties. To sustain these offensives, resupply was carried out by Japanese convoys, termed the "Tokyo Express" by the Allies. The convoys often faced night battles with enemy naval forces in which they expended destroyers that the IJN could ill-afford to lose. Fleet battles involving heavier ships and even daytime carrier battles resulted in a stretch of water near Guadalcanal becoming known as "Ironbottom Sound" from the multitude of ships sunk on both sides. However, the Allies were much better able to replace these losses. Finally recognizing that the campaign to recapture Henderson Field and secure Guadalcanal had simply become too costly to continue, the Japanese evacuated the island and withdrew in February 1943. In the six-month war of attrition, the Japanese had lost as a result of failing to commit enough forces in sufficient time.
Allied advances in New Guinea and the Solomons
By late 1942, Japanese headquarters decided to make Guadalcanal their priority. They ordered the Japanese on the Kokoda Track, within sight of the lights of Port Moresby, to retreat to the northeastern coast of New Guinea. Australian and US forces attacked their fortified positions and after more than two months of fighting in the Buna–Gona area finally captured the key Japanese beachhead in early 1943.
In June 1943, the Allies launched Operation Cartwheel, which defined their offensive strategy in the South Pacific. The operation was aimed at isolating the major Japanese forward base at Rabaul and cutting its supply and communication lines. This prepared the way for Nimitz's island-hopping campaign towards Japan.
Stalemate in China and Southeast Asia
In mainland China, the Japanese 3rd, 6th, and 40th Divisions, a grand total of around 120,000 troops, massed at Yueyang and advanced southward in three columns, attempting again to cross the Miluo River to reach Changsha. In January 1942, Chinese forces scored a victory at Changsha, the first Allied success against Japan.
After the Doolittle Raid, the Imperial Japanese Army conducted the Zhejiang-Jiangxi Campaign, with the goal of searching out the surviving American airmen, applying retribution on the Chinese who aided them, and destroying air bases. This operation started on 15 May 1942 with 40 infantry and 15–16 artillery battalions, but was repelled by Chinese forces in September. During this campaign, the Imperial Japanese Army left behind a trail of devastation and also spread cholera, typhoid, plague and dysentery pathogens. Chinese estimates put the death toll at 250,000 civilians. Around 1,700 Japanese troops died, out of a total 10,000 who fell ill when their biological weapons rebounded on their own forces.
On 2 November 1943, Isamu Yokoyama, commander of the Imperial Japanese 11th Army, deployed the 39th, 58th, 13th, 3rd, 116th and 68th Divisions, a total of around 100,000 troops, to attack Changde.
Chinese troops during the Battle of Changde in November 1943
During the seven-week Battle of Changde, the Chinese forced Japan to fight a costly campaign of attrition. Although the Imperial Japanese Army initially successfully captured the city, the Chinese 57th Division was able to pin them down long enough for reinforcements to arrive and encircle the Japanese. The Chinese then cut Japanese supply lines, provoking a retreat and Chinese pursuit. During the battle, Japan used chemical weapons.
In the aftermath of the Japanese conquest of Burma, there was widespread disorder and pro-Independence agitation in eastern India and a disastrous famine in Bengal, which ultimately caused up to 3 million deaths. In spite of these, and inadequate lines of communication, British and Indian forces attempted limited counter-attacks in Burma in early 1943. An offensive in Arakan failed, ignominiously in the view of some senior officers, while a long distance raid mounted by the Chindits under Brigadier Orde Wingate suffered heavy losses, but was publicized to bolster Allied morale. It also provoked the Japanese to mount major offensives themselves the following year.
In August 1943 the Allies formed a new South East Asia Command (SEAC) to take over strategic responsibilities for Burma and India from the British India Command, under Wavell. In October 1943 Winston Churchill appointed Admiral Lord Louis Mountbatten as its Supreme Commander. The British and Indian Fourteenth Army was formed to face the Japanese in Burma. Under Lieutenant General William Slim, its training, morale and health greatly improved. The American General Joseph Stilwell, who also was deputy commander to Mountbatten and commanded US forces in the China Burma India Theater, directed aid to China and prepared to construct the Ledo Road to link India and China by land. In 1943, the Thai Phayap Army invasion headed to Xishuangbanna at China, but were driven back by the Chinese Expeditionary Force.
Generalissimo Chiang Kai-shek and General Joseph Stilwell, Allied Commander-in-Chief in the China theatre from 1942–1945
Allied offensives, 1943–44
Allied attack routes against the Empire of Japan
Midway proved to be the last great naval battle for two years. The United States used the ensuing period to turn its vast industrial potential into increased numbers of ships, planes, and trained aircrew. At the same time, Japan, lacking an adequate industrial base or technological strategy, a good aircrew training program, or adequate naval resources and commerce defense, fell further and further behind. In strategic terms the Allies began a long movement across the Pacific, seizing one island base after another. Not every Japanese stronghold had to be captured; some, like Truk, Rabaul, and Formosa, were neutralized by air attack and bypassed. The goal was to get close to Japan itself, then launch massive strategic air attacks, improve the submarine blockade, and finally (only if necessary) execute an invasion.
In November 1943 US Marines sustained high casualties when they overwhelmed the 4,500-strong garrison at Tarawa. This helped the Allies to improve the techniques of amphibious landings, learning from their mistakes and implementing changes such as thorough pre-emptive bombings and bombardment, more careful planning regarding tides and landing craft schedules, and better overall coordination.
The US Navy did not seek out the Japanese fleet for a decisive battle, as Mahanian doctrine would suggest (and as Japan hoped); the Allied advance could only be stopped by a Japanese naval attack, which oil shortages (induced by submarine attack) made impossible.
The Allied leaders of the Asian and Pacific Theaters: Generalissimo Chiang Kai-shek, Franklin D. Roosevelt, and Winston Churchill meeting at the Cairo Conference in 1943
On 22 November 1943 US President Franklin D. Roosevelt, British Prime Minister Winston Churchill, and ROC Generalissimo Chiang Kai-shek, met in Cairo, Egypt, to discuss a strategy to defeat Japan. The meeting was also known as the Cairo Conference and concluded with the Cairo Declaration.
US submarines, as well as some British and Dutch vessels, operating from bases at Cavite in the Philippines (1941–42); Fremantle and Brisbane, Australia; Pearl Harbor; Trincomalee, Ceylon; Midway; and later Guam, played a major role in defeating Japan, even though submarines made up a small proportion of the Allied navies—less than two percent in the case of the US Navy. Submarines strangled Japan by sinking its merchant fleet, intercepting many troop transports, and cutting off nearly all the oil imports essential to weapons production and military operations. By early 1945, Japanese oil supplies were so limited that its fleet was virtually stranded.
The Japanese military claimed its defenses sank 468 Allied submarines during the war. In reality, only 42 American submarines were sunk in the Pacific due to hostile action, with 10 others lost in accidents or as the result of friendly fire. The Dutch lost five submarines due to Japanese attack or minefields, and the British lost three.
The torpedoed Yamakaze, as seen through the periscope of an American submarine, Nautilus, in June 1942
American submarines accounted for 56% of the Japanese merchantmen sunk; mines or aircraft destroyed most of the rest. American submariners also claimed 28% of Japanese warships destroyed. Furthermore, they played important reconnaissance roles, as at the battles of the Philippine Sea (June 1944) and Leyte Gulf (October 1944) (and, coincidentally, at Midway in June 1942), when they gave accurate and timely warning of the approach of the Japanese fleet. Submarines also rescued hundreds of downed fliers, including future US president George H. W. Bush.
Allied submarines did not adopt a defensive posture and wait for the enemy to attack. Within hours of the Pearl Harbor attack, in retribution against Japan, Roosevelt promulgated a new doctrine: unrestricted submarine warfare against Japan. This meant sinking any warship, commercial vessel, or passenger ship in Axis-controlled waters, without warning and without aiding survivors. At the outbreak of the war in the Pacific, the Dutch admiral in charge of the naval defense of the East Indies, Conrad Helfrich, gave instructions to wage war aggressively. His small force of submarines sank more Japanese ships in the first weeks of the war than the entire British and US navies together, an exploit which earned him the nickname "Ship-a-day Helfrich".
While Japan had a large number of submarines, they did not make a significant impact on the war. In 1942, the Japanese fleet submarines performed well, knocking out or damaging many Allied warships. However, Imperial Japanese Navy (and pre-war US) doctrine stipulated that only fleet battles, not guerre de course (commerce raiding) could win naval campaigns. So, while the US had an unusually long supply line between its west coast and frontline areas, leaving it vulnerable to submarine attack, Japan used its submarines primarily for long-range reconnaissance and only occasionally attacked US supply lines. The Japanese submarine offensive against Australia in 1942 and 1943 also achieved little.
As the war turned against Japan, IJN submarines increasingly served to resupply strongholds which had been cut off, such as Truk and Rabaul. In addition, Japan honored its neutrality treaty with the Soviet Union and ignored American freighters shipping millions of tons of military supplies from San Francisco to Vladivostok, much to the consternation of its German ally.
The I-400 class, the largest non-nuclear submarines ever constructed
The US Navy, by contrast, relied on commerce raiding from the outset. However, the problem of Allied forces surrounded in the Philippines, during the early part of 1942, led to diversion of boats to "guerrilla submarine" missions. Basing in Australia placed boats under Japanese aerial threat while enroute to patrol areas, reducing their effectiveness, and Nimitz relied on submarines for close surveillance of enemy bases. Furthermore, the standard-issue Mark 14 torpedo and its Mark VI exploder both proved defective, problems which were not corrected until September 1943. Worst of all, before the war, an uninformed US Customs officer had seized a copy of the Japanese merchant marine code (called the "maru code" in the USN), not knowing that the Office of Naval Intelligence (ONI) had broken it. The Japanese promptly changed it, and the new code was not broken again by OP-20-G until 1943.
Thus, only in 1944 did the US Navy begin to use its 150 submarines to maximum effect: installing effective shipboard radar, replacing commanders deemed lacking in aggression, and fixing the faults in the torpedoes. Japanese commerce protection was "shiftless beyond description," and convoys were poorly organized and defended compared to Allied ones, a product of flawed IJN doctrine and training – errors concealed by American faults as much as Japanese overconfidence. The number of American submarines patrols (and sinkings) rose steeply: 350 patrols (180 ships sunk) in 1942, 350 (335) in 1943, and 520 (603) in 1944. By 1945, sinkings of Japanese vessels had decreased because so few targets dared to venture out on the high seas. In all, Allied submarines destroyed 1,200 merchant ships – about five million tons of shipping. Most were small cargo carriers, but 124 were tankers bringing desperately needed oil from the East Indies. Another 320 were passenger ships and troop transports. At critical stages of the Guadalcanal, Saipan, and Leyte campaigns, thousands of Japanese troops were killed or diverted from where they were needed. Over 200 warships were sunk, ranging from many auxiliaries and destroyers to one battleship and no fewer than eight carriers.
Underwater warfare was especially dangerous; of the 16,000 Americans who went out on patrol, 3,500 (22%) never returned, the highest casualty rate of any American force in World War II. The Joint Army–Navy Assessment Committee assessed US submarine credits. The Japanese losses, 130 submarines in all, were higher.
Japanese counteroffensives in China, 1944
In mid-1944 Japan mobilized over 500,000 men and launched a massive operation across China under the code name Operation Ichi-Go, their largest offensive of World War II, with the goal of connecting Japanese-controlled territory in China and French Indochina and capturing airbases in southeastern China where American bombers were based.
Japanese plan for Operation Ichi-Go
During this time, about 250,000 newly American-trained Chinese troops under Joseph Stilwell and Chinese expeditionary force were forcibly locked in the Burmese theater by the terms of the Lend-Lease Agreement. Though Japan suffered about 100,000 casualties, these attacks, the biggest in several years, gained much ground for Japan before Chinese forces stopped the incursions in Guangxi.
Japanese occupation (red) of eastern China near the end of the war, and Communist guerrilla bases (striped)
Despite major tactical victories, the operation overall failed to provide Japan with any significant strategic gains. A great majority of the Chinese forces were able to retreat out of the area, and later come back to attack Japanese positions at the Battle of West Hunan. Japan was not any closer to defeating China after this operation, and the constant defeats the Japanese suffered in the Pacific meant that Japan never got the time and resources needed to achieve final victory over China. Operation Ichi-go created a great sense of social confusion in the areas of China that it affected. Chinese Communist guerrillas were able to exploit this confusion to gain influence and control of greater areas of the countryside in the aftermath of Ichi-go.
Japanese offensive in India, 1944
After the Allied setbacks in 1943, the South East Asia command prepared to launch offensives into Burma on several fronts. In the first months of 1944, the Chinese and American troops of the Northern Combat Area Command (NCAC), commanded by the American Joseph Stilwell, began extending the Ledo Road from India into northern Burma, while the XV Corps began an advance along the coast in Arakan Province. In February 1944 the Japanese mounted a local counter-attack in Arakan. After early Japanese success, this counter-attack was defeated when the Indian divisions of XV Corps stood firm, relying on aircraft to drop supplies to isolated forward units until reserve divisions could relieve them.
The Japanese responded to the Allied attacks by launching an offensive of their own into India in the middle of March, across the mountainous and densely forested frontier. This attack, codenamed Operation U-Go, was advocated by Lieutenant General Renya Mutaguchi, the recently promoted commander of the Japanese Fifteenth Army; Imperial General Headquarters permitted it to proceed, despite misgivings at several intervening headquarters. Although several units of the British Fourteenth Army had to fight their way out of encirclement, by early April they had concentrated around Imphal in Manipur state. A Japanese division which had advanced to Kohima in Nagaland cut the main road to Imphal, but failed to capture the whole of the defences at Kohima. During April, the Japanese attacks against Imphal failed, while fresh Allied formations drove the Japanese from the positions they had captured at Kohima.
As many Japanese had feared, Japan's supply arrangements could not maintain her forces. Once Mutaguchi's hopes for an early victory were thwarted, his troops, particularly those at Kohima, starved. During May, while Mutaguchi continued to order attacks, the Allies advanced southwards from Kohima and northwards from Imphal. The two Allied attacks met on 22 June, breaking the Japanese siege of Imphal. The Japanese finally broke off the operation on 3 July. They had lost over 50,000 troops, mainly to starvation and disease. This represented the worst defeat suffered by the Imperial Japanese Army to that date.
Although the advance in Arakan had been halted to release troops and aircraft for the Battle of Imphal, the Americans and Chinese had continued to advance in northern Burma, aided by the Chindits operating against the Japanese lines of communication. In the middle of 1944 the Chinese Expeditionary Force invaded northern Burma from Yunnan. They captured a fortified position at Mount Song. By the time campaigning ceased during the monsoon rains, the NCAC had secured a vital airfield at Myitkyina (August 1944), which eased the problems of air resupply from India to China over "The Hump".
Chinese forces on M3A3 Stuart tanks on the Ledo Road
Beginning of the end in the Pacific, 1944
In May 1943, the Japanese prepared Operation Z or the Z Plan, which envisioned the use of Japanese naval power to counter American forces threatening the outer defense perimeter line. This line extended from the Aleutians down through Wake, the Marshall and Gilbert Islands, Nauru, the Bismarck Archipelago, New Guinea, then westward past Java and Sumatra to Burma. In 1943-44, Allied forces in the Solomons began driving relentlessly to Rabaul, eventually encircling and neutralizing the stronghold. With their position in the Solomons disintegrating, the Japanese modified the Z Plan by eliminating the Gilbert and Marshall Islands, and the Bismarck Archipelago as vital areas to be defended. They then based their possible actions on the defense of an inner perimeter, which included the Marianas, Palau, Western New Guinea, and the Dutch East Indies. Meanwhile, in the Central Pacific the Americans initiated a major offensive, beginning in November 1943 with landings in the Gilbert Islands. The Japanese were forced to watch helplessly as their garrisons in the Gilberts and then the Marshalls were crushed. The strategy of holding overextended island garrisons was fully exposed.
In February 1944, the US Navy's fast carrier task force, during Operation Hailstone, attacked the major naval base of Truk. Although the Japanese had moved their major vessels out in time to avoid being caught at anchor in the atoll, two days of air attacks resulted in significant losses to Japanese aircraft and merchant shipping. The Japanese were forced to abandon Truk and were now unable to counter the Americans on any front on the perimeter. Consequently, the Japanese retained their remaining strength in preparation for what they hoped would be a decisive battle. The Japanese then developed a new plan, known as A-GO . A-GO envisioned a decisive fleet action that would be fought somewhere from the Palaus to the Western Carolines. It was in this area that the newly formed Mobile Fleet along with large numbers of land-based aircraft, would be concentrated. If the Americans attacked the Marianas, they would be attacked by land-based planes in the vicinity. Then the Americans would be lured into the areas where the Mobile Fleet could defeat them.
On 15 June 1944, 535 ships began landing 128,000 US Army and Marine Corps personnel on the island of Saipan in the Northern Marianas. The Allies aimed to establish airfields near enough the Japanese Home Islands, including Honshu, the location of Tokyo, to allow their bombing with the new Boeing B-29 Superfortress. The ability to plan and execute such a complex operation in the space of 90 days was indicative of Allied logistical superiority.
A month after the invasion of Saipan, the US recaptured Guam and captured Tinian. Once captured, the islands of Saipan and Tinian were used extensively by the United States military as they finally put mainland Japan within round-trip range of American B-29 bombers. In response, Japanese forces attacked the bases on Saipan and Tinian from November 1944 to January 1945. At the same time and afterwards, the United States Army Air Forces based out of these islands conducted an intense strategic bombing campaign against the Japanese cities of military and industrial importance, including Tokyo, Nagoya, Osaka, Kobe and others.
When the Americans landed on Saipan in the Marianas the Japanese viewed holding Saipan as an imperative. Consequently, the Japanese responded with their largest carrier force of the war: the nine-carrier Mobile Fleet under the command of Vice Admiral Jisaburō Ozawa, supplemented by an additional 500 land-based aircraft. Facing them was the US Fifth Fleet under the command of Admiral Raymond A. Spruance, which contained 15 fleet carriers and 956 aircraft. The clash was the largest carrier battle in history.
The battle did not turn out as the Japanese had hoped. During the previous month, US destroyers had destroyed 17 out of 25 submarines in Ozawa's screening force and repeated American air raids destroyed the Japanese land-based aircraft.
Map of the Battle of the Philippine Sea
On June 19, a series of Japanese carrier air strikes were shattered by strong American defenses. The result was later dubbed the Great Marianas Turkey Shoot. All US carriers had combat-information centers, which interpreted the flow of radar data and radioed interception orders to the combat air patrols. The few Japanese attackers that managed to reach the US fleet in a staggered sequence encountered massive anti-aircraft fire with proximity fuzes. Only one American warship was slightly damaged. On the same day, Shōkaku was hit by four torpedoes from the submarine Cavalla and sank with heavy loss of life. The Taihō was also sunk by a single torpedo, from the submarine Albacore. The next day, the Japanese carrier force was subjected to an American carrier air attack and suffered the loss of the carrier Hiyō. The four Japanese air strikes involved 373 carrier aircraft, of which 130 returned to the carriers. Many of these survivors were subsequently lost when Taihō and Shōkaku were sunk by American submarine attacks. After the second day of the battle, losses totaled three carriers and 445 aircrew with more than 433 carrier aircraft and around 200 land-based aircraft. The Americans lost 130 aircraft and 76 aircrew, many losses due to aircraft running out of fuel returning to their carriers at night.
Although the defeat at the Philippine Sea was severe in terms of the loss of the three fleet carriers Taihō, Shōkaku and the Hiyō, the real disaster was the annihilation of the carrier air groups. These losses to the already outnumbered Japanese fleet air arm were irreplaceable. The Japanese had spent the better part of a year reconstituting their carrier air groups, and the Americans had destroyed 90% of it in two days. The Japanese had only enough pilots left to form the air group for one of their light carriers. The Mobile Fleet returned home with only 35 aircraft of the 430 with which it had begun the battle. The battle ended in a total Japanese defeat and resulted in the virtual end of their carrier force.