Japan's Imperial Army

by Edward J Drea

  Occupation policy was decided at a November 20, 1941, IGHQ liaison conference. Military administration in occupied territories would restore security, acquire strategic raw materials, and insure the operational forces’ self-sufficiency. A few days later the army took responsibility for Hong Kong, the Philippines, Malaya, Sumatra, Java, British Borneo, and Burma; the navy controlled Dutch Borneo, Celebes, Malacca Islands, the Lesser Sunda Islands, New Guinea, the Bismarck Archipelago, and Guam.86 Thus the army’s focus was primarily continental, the navy’s maritime, the inevitable result of the services’ chronic inability to agree on a joint strategy.

  Military strategy relied on the classic short-term war scenario to seize and quickly eliminate western bases in East Asia while occupying strategic points in the southern region. This in turn would hasten the collapse of Chiang Kai-shek’s regime and end the China fighting. Japan would also cooperate with its Axis partners, Germany and Italy, to compel Great Britain to surrender, which would shatter America’s will to fight. Although the army was bogged down in a protracted war in China, Sugiyama informed Hirohito on December 1 that Japan had a once-in-a-lifetime chance to break the West’s economic embargo and achieve autarky.87

  Traditional assumptions underpinned this strategy: if Japan could control Southeast Asia’s raw materials, the empire probably could achieve self-sufficiency by drawing on those resources to fight a protracted war. Control of the Indian Ocean would cut the line of communication from India to Great Britain, leaving the British short of supplies and raw materials and unable to resist the imminent German invasion. The British capitulation would cause the United States to lose its will to fight, allowing Japan to use neutrals and the Vatican to achieve a favorable negotiated settlement that left the empire in advantageous strategic position.

  The army marched off to war against the West with no means to defeat the United States, much less an allied coalition. It never reconciled its traditional dilemma over a short-term or a protracted war, and its overreliance on Nazi Germany to defeat Britain only made an already flawed strategy even weaker. There was no strategic or operational plan after the first six months of hostilities and no thoughtful consideration given to war termination. Trusting in the military prowess of Nazi Germany, army leaders counted on Japan’s intangible qualities to overcome a decadent United States. The decisions of late 1941 flowed naturally from the army’s past experience, strategic perspective, operational and tactical doctrine, and its carefully cultivated belief in Japanese superiority.

  11

  The Asia-Pacific War

  Japan’s war with the West began on December 8, 1941 (Tokyo time), with surprise attacks on British Malaya and Pearl Harbor, Hawaii, preceding a formal declaration of war. Although the tactics seemed to fit a traditional Japanese pattern of preemptive strikes, the opening attacks on Chinese transports in 1894 and against the Russian naval base at Port Arthur in 1905 were integrated parts of a comprehensive diplomatic, political, and military strategy designed to force an early decisive engagement that would lead to a negotiated settlement of hostilities. In the 1941 plans these ingredients were lacking.

  The Pearl Harbor raid temporarily neutralized the U.S. Pacific Fleet and allowed the army to conduct amphibious operations against the Netherlands East Indies and the Philippines. The strategic objective was to create a self-sufficient Japan able to fight a protracted war. Initial operational plans included no fixed time limits, except that they should be accomplished within 150 days in order to move either north in the spring against the Soviet Union or defend against a Soviet attack. At the same time, the plans called for Japanese forces to fortify and defend their new and massive southern perimeter until the Allies grew tired of attacking and agreed to a negotiated peace.1 The strategy acknowledged that the army lacked the means to force a decisive land battle and premised its seize-and-hold strategy on a protracted war of attrition whose end game depended on Germany knocking Britain out of the war. Once Britain surrendered, army leaders hoped the United States would agree to terms.

  The navy could bring about a decisive fleet engagement with the Americans in the western Pacific, but it was much less confident about fighting a protracted war of attrition.2 Furthermore, the naval general staff had aggressively extended the location of the decisive battle, counting on land-based airpower and air bases in the Mandated Islands to project power westward and shield the home islands from enemy reprisals. The navy’s requirements for troops to secure its far-flung gains steadily drew the army into the South and Central Pacific regions.

  The army originally committed less than half its operational aircraft and one-fifth of its personnel to the opening campaigns, whose purpose was to secure the resources of the southern regions and leverage that success to end the war in China. A December 12 cabinet resolution designated the conflict with the western powers and China the Greater East Asia War, a designation that signified the goal of building a new order in East Asia but not necessarily limiting the war to that geographic area.3

  On December 8, naval land-based bombers flying from Taiwan surprised and destroyed most of the U.S. Army air units in the Philippines on the ground. Two days later naval land-based bombers operating from bases near Saigon, French Indochina, sank the British battleships Prince of Wales and Repulse, losing just three aircraft in the attack. During November, army fighters and bombers of the Third Composite Wing (three air divisions) had deployed from southern China to forward bases in Cambodia and southern Indochina. Augmented by the navy’s 22d Air Flotilla, the more than 540 aircraft protected the Malaya-bound invasion fleet.4

  Under Lt. Gen. Yamashita Tomoyuki the Twenty-fifth Army’s 18th Division moved south along Malaya’s east coast while the 5th Division raced down the west coast. The fast-moving advance—it averaged about 12 miles a day—relied on confiscated allied supplies, especially fuel oil, and the capture of air bases to enable its air umbrella to displace forward to support ground operations. Without air cover, Allied forces were subjected to repeated aerial bombing and strafing that made it almost impossible to concentrate or move entire units effectively. Light and medium tanks led breakthroughs against British Commonwealth forces lacking antitank defenses. In combination with this shock action, Japanese infantrymen relied on their standard envelopment tactics, making shallow hooks into the jungle to outflank and outmaneuver their road-bound enemy.

  By the end of January 1942 the Twenty-fifth Army had reached Singapore Island, and on February 15 Yamashita conquered the city and fortress. Two days earlier Japanese troops had overrun the Alexandria Barracks Hospital, bayoneting more than 300 hospital personnel, including wounded patients, in a precursor to the serial atrocities—rape, looting, and murder—that followed Singapore’s capitulation. The Japanese occupiers targeted the colony’s large Chinese population for reprisals and took about 130,000 British Commonwealth troops into captivity, many of whom were eventually consigned to railroad construction projects in Burma.

  Meanwhile, the Fourteenth Army under Lt. Gen. Homma Masaharu landed on Luzon, Philippines, on December 22, 1941, and marched south on Manila. Ambiguous operational directives left Homma unsure whether his objective was the Philippine capital or the destruction of Gen. Douglas MacArthur’s American-Filipino forces. Japanese air superiority again provided an insurmountable advantage, and MacArthur soon declared Manila an open city. The Fourteenth Army occupied the capital on January 2, 1942, and Homma believed that he had achieved the campaign’s objectives.

  MacArthur, however, withdrew into the rugged Bataan Peninsula, where Homma’s January 9 offensive failed to dislodge him. After this painful setback, a second offensive, launched on April 3, defeated the hungry, sick, and poorly supplied Allies on Bataan. About 12,000 U.S. and 58,000 Filipino personnel were taken prisoner and forced to march about sixty miles to a processing camp. Lacking adequate food, medicine, and water and driven forward by unforgiving Japanese guards, perhaps as many as 600 Americans and 5,000–10,000 Filipinos perished in what became known as the
Bataan Death March.5 It was a foretaste of the treatment the Japanese meted out during their occupation of the Philippines. Corregidor Island in Manila Bay held out until May 6, by which time MacArthur was safely in Australia. The Fourteenth Army’s handling of the campaign, its duration, and the unexpectedly heavy Japanese casualties cost Homma his reputation and command.

  Elsewhere, on the night of December 18 the Twenty-third Army attacked Hong Kong, but unexpectedly stubborn British, Canadian, Australian, and Chinese resistance stretched out the fighting a full week before the surrender on Christmas night. Japanese soldiers had raped and murdered westerners and Chinese during the fighting, and afterward the atrocities against the Chinese continued. Thousands of British and Canadian troops went into captivity. In central China, Gen. Anami launched his second Changsha offensive on December 24 and entered the city a week later, only to meet fierce Chinese counterattacks that cut off two of his divisions in early January 1942. Outnumbered and outmaneuvered, Anami retreated northward.

  Naval infantry units captured Guam in the Marianas on December 10; two weeks later, after an initial repulse, naval special landing forces seized Wake Island, an important communications center and airfield in the western Pacific. The navy then pushed into the southwest Pacific, justifying this unanticipated expansion as necessary to protect the flank approaches to the Combined Fleet’s advance base and anchorage at Truk, Caroline Islands, which fell within range of long-range heavy bombers staging from Rabaul in the Bismarck chain. On January 4, 1942, multifront joint attacks opened against Rabaul, the Solomon Islands, and the northeast New Guinea coast. Joint forces occupied Rabaul by January 23 and subsequently murdered captured Australian personnel. On February 19, navy carrier-based aircraft raided Darwin, Australia. The navy seized bases at Lae and Salamua on the northeast New Guinea coast on March 8. Minor naval construction units also moved to Tulagi, Solomon Islands.

  These operations were incidental to the goal of the southern operation, namely the capture of the oil- and resource-rich Netherlands East Indies (NEI). In mid-January 1942 the Sixteenth Army under Lt. Gen. Imamura Hitoshi invaded Borneo, and about 400 naval paratroopers attacked Manado on Celebes. A few hundred army paratroopers dropped on Palembang, Sumatra, on February 14 and seized the NEI’s richest oil fields. On the night of February 28–March 1 the Battle of the Java Sea eliminated Allied naval power in the NEI, and on March 1 units of the Sixteenth Army landed in Java, where they quickly occupied Surabaya and the capital, Batavia. Dutch forces surrendered eight days later, and captured military personnel and civilians were placed in internment camps. Although army headquarters in Tokyo regarded Imamura as overly lenient with the Indonesians, tens of thousands of them would later perish while working as forced laborers on Japanese projects throughout Southeast Asia.

  Two divisions of the Fifteenth Army invaded Burma on January 20 from staging bases in Thailand. Despite initial—and for China, deeply humiliating—British objections, Chiang Kai-shek sent Chinese troops, including his only mechanized division, to assist in Burma, partly in order to fight alongside his new allies and partly to defend China’s one remaining connection with the outside world.6 The Chinese along with their new British and American allies were routed, mainly because of a lack of air and naval power and ill-equipped and poorly trained infantry. Trucks and tanks left the Allies dependent on roads while the lightly armed Japanese took to the jungle, quickly outflanking and enveloping defenders. Profound disagreements over strategy, including whether to defend Mandalay in northern Burma or counterattack south toward Rangoon, did lasting harm to Allied relations.

  By March 8 the Japanese had occupied the capital at Rangoon. Then two more divisions landed near Rangoon in early April to reinforce a two-pronged northward offensive against Mandalay and Laisho. The former would destroy Commonwealth forces, and the latter would seal the Burma Road to cut off supplies to China. Mandalay fell on May 4, and by the end of the month the Fifteenth Army occupied the coast from Ayakab to northern Burma. Once again, air superiority (this time reinforced with army air units from the Philippines) combined with fast-moving infantry enveloping tactics threw the road-bound British-Indian forces into disarray. British suspicion of Chinese fighting effectiveness restricted their deployment to northeastern Burma and limited the Chinese role during the campaign.

  In late March the army occupied Andaman and Nicobar islands in the Indian Ocean, and in early April Combined Fleet carrier aircraft bombed Colombo, Ceylon, and the British naval base at Tricomcomlee. Fleet actions sank one light aircraft carrier, two heavy cruisers, and three transports, driving the British Navy from the Indian Ocean.

  Although the Imperial General Headquarters had originally planned a strategic defensive, the first stage of operations had progressed so smoothly that the services saw opportunities for further offensives. Neither service had concrete plans nor shared common objectives. The navy, for example, would establish an outer perimeter that reached to Australia, Hawaii, and India. Allied attempts to defend those vital areas would bring about the long-sought climactic fleet engagement. The army, however, was content to defend the current gains and consolidate its forces to repulse enemy counteroffensives anticipated after 1943. In other words, the army wanted to dig in to fight a protracted war of attrition whereas the navy demanded further expansion and the destruction of the U.S. fleet to make a protracted war possible.7

  In an economy-of-force move, army authorities expected to withdraw sizeable numbers of troops from the southern front to refit, reequip, and modernize them for the long-term struggle. Plans would reduce the 450,000 troops (eleven divisions, seventy-seven air squadrons) to 250,000 personnel (seven divisions, fifty air squadrons) by the end of 1942.8 The 200,000 recycled troops would reinforce Japan’s northern front in anticipation of operations against the Soviet Union beginning in the spring of 1942 and also be available as a strategic reserve to check any Allied counteroffensive in the southern areas, which the high command anticipated would occur sometime after 1943.

  At the March 7 liaison conference, the IGHQ accurately identified the Allied forces’ priority of defeating Germany first and deduced that this strategic decision would delay any counteroffensive against Japan until after 1943. Attempts would, of course, be made to reopen the Burma Road to aid China, but Japanese agitation of anti-British Indian nationalists would check this move. For the first time the army’s strategic planners expressed doubt that Germany could defeat the USSR in 1942, but they held out hope that German occupation of the Caucasus might cause Stalin’s regime to collapse.

  As for the British and American allies, they were materially powerful but lacked individual fighting spirit. The loss of their advanced bases and colonies had lowered overall Allied morale, and the impending British surrender would be a profound psychological shock to the United States, where societal unrest was likely to develop as the American standard of living declined and wartime sacrifices increased without hope of victory. Based on these encouraging assessments, the liaison conference decided to expand the current gains and create an impregnable strategic defensive perimeter.9

  Outstanding early successes only concealed Japan’s grave structural weakness. The army was already overextended in China, and each new conquest in Asia or the Pacific seemed to demand still another troop commitment to protect the recently acquired territory. Thus the navy needed Rabaul to protect Truk’s southern flank, but then needed Port Moresby to protect Rabaul’s flank, and then needed northern Australia to protect Moresby. It needed the Solomons as advance bases for operations against Port Moresby and Australia. And Fiji and Samoa became essential in order to sever the line of communication between Australia and the United States. In China, generals clamored for offensives against Chongqing; in Burma they wanted to drive to India; and in the southern region, admirals dreamed of invading Australia and India.

  The imperial navy approved the F-S (Fiji-Samoa) and the Midway operations on April 5. The former would sever the line of communication between the
United States and Australia (and thereby deny Australia’s use as a forward staging base for the Allied counteroffensive), and the latter would provoke the decisive naval engagement and destruction of the American fleet. It was further decided to occupy the Aleutian Islands to prevent air attacks on Japan from that direction. The Midway operation came as a total surprise to the army, which went along because it was solely a navy operation and there was nothing the army could do about it.10

  These plans were already in motion when Lt. Col. James Doolittle’s U.S. carrier-based medium bombers struck Tokyo and several other Japanese cities in mid-April 1942. The daring raids shocked Japanese authorities, lifted American morale, and were a disaster for China. To prevent future air raids on the homeland, IGHQ ordered the occupation of airfields in eastern China’s Zhejiang and Jiangxi provinces that lay within striking range of Japan. Five divisions and three independent mixed brigades of the Thirteenth Army in Shanghai struck southwestward and by mid-May had pushed out from Hangzhou to link up with two divisions from the Eleventh Army at Nanchang.

  The Doolittle raid embarrassed the army, which was responsible for air defense of the home islands and was thus persuaded to join the Midway operation to thwart future carrier-based air attacks. Also, to strengthen homeland air defenses, the army withheld several fighter groups previously scheduled to support operations in the Solomons with effects on subsequent fighting there.11

  By September the Japanese had destroyed the threatening Chinese air bases, some only just constructed, and laid waste to surrounding areas while clearing the 180-mile Hangzhou-Nanchang rail corridor. A neglect of logistics, however, marred the campaign. Shortages of food, ammunition, and transportation left hungry Japanese soldiers mired in the mud during the heaviest rainy season in sixty years. Sickness, especially malnutrition, accounted for three times the number of the 4,000 battle casualties. Thereafter the Eleventh Army at Nanchang secured the vast area running along the north and south banks of the Yangzi. The Doolittle raid also encouraged army planners to attack the Nationalist capital at Chongqing, and by the end of June 1942 the army was once again on the offensive in the South and Southwest Pacific, the Aleutians, and central China.