Japan's Imperial Army

by Edward J Drea

  The army continually analyzed its battlefield performance in the Pacific campaigns and distributed lessons learned to field units, but it remained preoccupied with its traditional Soviet opponent and assumed that the navy would handle the Americans. Not until September 1943 did the inspector-general of military education direct army schools to switch curricula from tactics, training, and education for war with the Soviet Union and give top priority to instruction on countering American operations.43 School commandants protested, citing a lack of suitable materials and curricula on U.S. tactics and no curriculum available for instructors. One frustrated instructor announced the change to his class, remarking that he didn’t know a damn thing about American tactics.44

  During the first half of 1944, circumstances had prevented units from conducting the waterline defense and gave the Americans a conflicting sense of evolving Japanese tactics. At Biak in May and June 1944 the counterattack against the American lodgment foundered, not from any reluctance to execute the assault but because the rough terrain and distance from the main Japanese positions to the invasion beaches made coordinated, concentrated attacks impossible. After piecemeal attacks failed, the battered defenders retreated and then fought a tenacious delaying action from the numerous caves that pockmarked the island. At Peleliu in September 1944 the failure of the tank-infantry assault to split the U.S. Marine invaders on the invasion beaches—the original battle plan—forced the garrison into a protracted defense from the island’s coral caves. The saw-toothed terrain canalized American attacks and enhanced the defense, and a two- or three-day campaign turned into a two-month nightmare.45 It appeared to the United States that the Japanese army was adjusting tactics to engage in protracted fighting.

  It was not until mid-August 1944, however, that IGHQ issued “Essentials of Island Defense” (the first completely new tactical manual since 1928), which instructed units to organize hardened positions for a protracted defense, including a last-stand fight to the death. The new doctrine was not a simple static defense but instead preached a mobile defense organized around fortifications and strongpoints that would serve as launching points to counterattack the invaders. Counteramphibious warfare doctrine now stressed improved fortifications, greater unit dispersal, successful concealment, and—of course—fighting spirit.46

  In October the draft counteramphibious landing doctrine superseded “Essentials of Island Defense.” Based on practical combat experience and lessons learned, the army officially abandoned defense at the water’s edge and called for inland defenses in depth. Time and materiel, however, were unavailable to construct the multipositional defenses the manual advised. More important, at the military academy and staff college, officers had absorbed the message that the offensive pressed home with cold steel won battles and wars and that imbedded offensive doctrine could not be changed overnight.47 As late as April 1945, for example, even the emperor would question the Okinawa garrison’s reasons for abandoning the water’s edge defense and giving up the island’s airfields without a fight, a sentiment shared by IGHQ, other major headquarters, and probably most line-unit commanders on Okinawa.

  The long-sought-after Shō operation came at Leyte, Philippines, after MacArthur’s October 20 landing there. The navy threw its remaining capital ships into an ambitious, complex, and daring three-pronged attack on the beachhead that nearly succeeded, but finally ended with the loss of thirteen capital ships, three light cruisers, eight destroyers, and six submarines without achieving their objectives. As for the army, it had initially expected to fight the main ground battle on Luzon, but IGHQ and the general staff uncritically accepted the navy’s exaggerated battle claims that its pilots had destroyed several American aircraft carriers during the October 12–15 Battle of the Taiwan Sea.

  Believing that U.S. air and surface elements had been eliminated during the subsequent surface naval engagements in the central Philippines, the army general staff thought that MacArthur was trapped in his beachhead. Ignoring the advice of Lt. Gen. Yamashita Tomoyuki, the commander of the Fourteenth Area Army who wanted to fight the critical battle on Luzon, IGHQ ordered ground reinforcements to Leyte, expecting that they would formally accept MacArthur’s surrender. Eventually elements of seven divisions were thrown into the Leyte campaign, where all were lost in the fighting. Furthermore, stripping the strategic reserve from Luzon fatally compromised Yamashita’s overall strategy to defend the Philippines.48

  China-Burma-India

  By 1943 IGHQ was routinely transferring first-line divisions from China to shore up hard-pressed Japanese forces in the Pacific and southwest Asia theaters. To replace them, the army upgraded brigades to division status, but the new divisions lacked mobility and artillery support. These ersatz formations took over security in the occupied zones of China while the remaining first- and second-line divisions conducted limited offensives along wide frontages that employed converging columns to seize objectives. In North China the army wreaked as much havoc as possible to disrupt the Chinese military plans and sow domestic civilian disorder. Unable to garrison more conquered territory, the Japanese invariably withdrew, and the Chinese Communist or Central Government troops slowly reclaimed the devastated region.

  The final major operation of 1943 against Changde (November–December) was the most ambitious that year and involved six divisions. The newly established Chinese-American Composite Wing and U.S. Army Air Forces delivered effective air support that forced the Japanese ground troops to assemble and move only at night. Since 1942 the Japanese Army Air Force had taken responsibility for air operations on the continent, but the appearance of American airpower in China forced it onto the defensive. In mid-December 1943 army bombers successfully struck Chinese airfields and air bases in southwestern China, but they could not prevent Chinese forces from retaking Changde on December 9.

  In April 1944 U.S.-trained and -equipped Chinese divisions in Burma (the X-Force) and smaller American units tried to reopen the Burma Road leading into China as part of a limited Allied counteroffensive in north Burma. The combined forces reached Myitkyina in mid-May, causing the Thirty-third Army to abandon north Burma. The stubborn Japanese garrison at Myitkyina held out until early August against three Chinese divisions, giving the Japanese time to prepare another defensive line farther south.

  During the Myitkyina siege, the fighting around Imphal-Kohima crested, menacing the Allied supply line—including that of the X-Force. Meanwhile, in early May, the Chinese 20th Army Group (sixteen divisions) in Yunnan (Kunming), known as the Y-Force, crossed the Salween River on a broad front about 100 miles east of Myitkyina, attempting to open the Burma route from the northeast by ejecting the Japanese 56th Division from Longling and ultimately linking up with the X-Force at Bhamo, Burma.

  On June 1, the Chinese 11th Army Group joined the fighting on the southern flank, threatening to isolate the Japanese mountain strongholds. Because the Japanese still held Myitkyina, Chiang could not reinforce the Y-Force; consequently, Japanese counterattacks against Chinese river crossing points, skillful use of the jungle-covered mountain ranges to slow the Chinese drive, the onset of the monsoon season, and a successful counterstroke against the southern arm of the Chinese pincer halted the advance in late June. Further counterattacks to drive the Chinese west of the Salween ended in failure in mid-September. By this time the catastrophic defeat of the Japanese Fifteenth Army along the Burma-India border relegated the Thirty-third Army to the strategic defensive. Simultaneously, the growing Chinese awareness of the actual scope of the Ichigō (Number One) operation diverted its attention from north Burma.

  The Ichigō offensive undertaken by the China Expeditionary Army between mid-April 1944 and early February 1945 was the largest military operation in the army’s history, using approximately 500,000 troops (twenty divisions)—about 80 percent of the CEA’s forces—supported by almost 800 tanks, more than 1,500 artillery guns, over 15,500 vehicles, and 240 aircraft. It aimed to destroy the American B-29 air bases in China within range o
f the Japanese mainland and to force open an overland route from Pusan, Korea, to French Indochina. Beginning around April 1944, replacements for Ichigō were brought from Korea and Manchuria to central China, but many were poorly equipped, sharing rifles until they could arm themselves with discarded Chinese weapons.49

  Ichigō’s first phase (mid-April to late May 1944) involved a north-south pincer to clear the southern portion of the Peking-Wuhan Railway and occupy Luoyang. The second stage (May to December 1944) consisted of massive sequenced offensives as the Eleventh Army pushed south, captured Changsha and Hengyang (which was desperately defended), and with the Twenty-third Army seized several American air bases. The Twenty-first Army then moved from northern Indochina to meet these forces, opening an overland line of communication running the length of China.

  To secure the Indochina rear area, in early March 1945 the Japanese army preempted a suspected coup by attacking the French garrisons in Indochina (about 50,000 strong) and, after bitter fighting in the north, driving the French into southern China. They then removed French administrators and encouraged the Vietnamese to take control. “Liberation” was costly because the Japanese army confiscated Vietnam’s rice crop and disrupted the food distribution system to create a famine that claimed perhaps 200,000 Vietnamese lives. All this suffering mattered little in the larger conflict because by this time the Asia-Pacific War had turned decisively against Japan.

  In Burma the Chinese had made good progress since mid-October uncovering the Thirty-third Army’s left flank by advancing south from Myitkyina. Three divisions linked up at Bhamo and then struck southwest, pushing back the weakened Japanese, who had retreated to the east side of the Shwell River by December.50 Although the Ichigō offensive did divert Chinese troops from Burma, the remaining units continued their two-pronged offensive in northern Burma, linking up in late January 1945, reopening the entire Burma Road in February, and reaching Lashio in mid-March. These actions broke the five-year-long Japanese blockade of China and culminated in a decisive land campaign in Burma.

  The Japanese army still held most Chinese cities and huge swaths of territory, but it was incapable of further offensive operations. During the eight-year China war, Japan suffered 410,000 killed (230,000 after December 1941) and 920,000 wounded. Although no reliable figures are available for Chinese losses, perhaps as many as ten million Chinese soldiers died during the fighting, and civilian casualties certainly surpassed that number. The protracted fighting also dislocated tens of millions of Chinese, who took to the roads in search of survival.51 If the army had gone to war with the West in 1941 to break the stalemate in China, four years later the China theater was still stalemated, but with a major difference: Japan now confronted a mortal danger from the American counteroffensive.

  On January 20, 1945, the services approved the first joint operational plan of the war, indeed the first in Japan’s modern military history. Operation Ten-gō (Heaven) relied on special attack or suicide tactics, counting on elite air units to shatter the American offensive. Operation Ketsu-gō (Decisive) would prepare homeland defenses against invasion. The Fourteenth Area Army would continue fighting on Luzon to divert Allied strength while the army and navy strengthened the Ogasawaras (Iwo Jima) and Okinawa against enemy attack as part of Ten-gō. The army regarded the latter two islands as outpost battles and preliminaries to the decisive battle of the war—the American invasion of Japan. Perhaps more accurately, all three were homeland battles, because during the fighting on Iwo Jima and Okinawa, the home islands fell under U.S. heavy bomber attacks of growing savagery, an increasingly effective naval blockade, and naval carrier air and surface ship attacks.52

  IGHQ’s mid-February strategic estimate conceded the overwhelming material superiority of the United States, anticipated that the Americans would use their British and Chinese allies to wear down Japan’s continental defenses, and presumed that the United States would pressure the Soviet Union to enter the war against Japan. But the Americans were operating on extended lines of communication vulnerable to attack. They were averse to heavy casualties, and if Japan adopted a shūkketsu (bleeding) strategy to defend the Ogasawaras and Okinawa, the army could buy time to build up homeland defenses for the war’s climactic battle and make the Americans think twice about the consequences of invading the home islands.53

  The small volcanic island of Iwo Jima, midway between Tokyo and Saipan, was the first shūkketsu battle. The roughly 11-square-mile island restricted maneuver and was ideal for defense. Lt. Gen. Kuribayashi Tadamichi had worked since June 1944 to transform it into a killing ground. Kuribayashi’s plan was simple; he intended to hold out as long as possible, overriding objections from offensive-minded officers who advocated the traditional waterline defense. On February 19, three U.S. Marine divisions stormed Kuribayashi’s honeycomb of cave and underground fighting positions in one of the most ferocious land battles of the Pacific War. Kuribayashi’s final message transmitted to IGHQ on March 16 conceded the American victory, but he pledged to return as a spirit to witness the imperial army turn defeat into victory.54 The fighting claimed 21,000 Japanese dead and more than 26,000 U.S. Marine casualties, including almost 7,000 killed. For the first time in the Pacific counteroffensive, the American attackers had suffered higher casualties than the Japanese defenders. The shūkketsu strategy had made a point.

  For all the bloodshed, however, Iwo Jima was a prelude to Okinawa, where a large civilian population made for an entirely different campaign. Army commanders ruthlessly co-opted civilians to support their determination to hold the island regardless of cost. Shortly after the American landing on Saipan, on June 28, 1944, the war ministry and the cabinet approved the evacuation of noncombatants from Okinawa and other threatened islands. The army supported relocation for tactical, not humanitarian, reasons. The Thirty-second Army Chief of Staff, Lt. Gen. Chō Isamu, minced no words with the Okinawa legislature, telling it that combat units could maneuver more freely with fewer civilians in the way.55

  The evacuation of Okinawa began in tragedy. In mid-August 1944 a U.S. submarine torpedoed a transport packed with refugees, and more than 700 schoolchildren perished. Fearful of more submarine attacks and not fully convinced the Americans would invade, Okinawans resisted evacuation—but prefectural authorities used schoolteachers, neighborhood associations, and village councils to pressure people to leave. As it turned out, the first ship was the only one lost during an evacuation that lasted into mid-March 1945, involved 187 vessels, and removed about 60,000 children to Japan and 20,000 civilians to Taiwan.56 The army also ordered a mass evacuation of 60,000 elderly and children from southern Okinawa, the anticipated battleground, to the desolate northern end of the island. Any lingering doubts about the army’s regard for the Okinawans disappeared after Chō’s newspaper editorial in January 1945 declared the army’s intention to confiscate all food once the enemy landed. The army’s mission, he wrote, was to win, and it would not allow itself to be defeated by helping starving civilians.57

  Yet the army ordered civilians to do its bidding. The Thirty-second Army conscripted or recalled to active duty 25,000 Okinawans between the ages of 17 and 45 and deployed them in poorly equipped self-defense or volunteer units. Scores of middle school students were conscripted and organized into special student units. Young girls from middle and high schools formed the female students’ field force, worked as nurses in field hospitals, and carried rations and ammunition to fighting units.58 During the battle, soldiers murdered civilians who got in their way. They confiscated food from starving women and children. They executed islanders speaking in the local dialect as spies. On smaller outlying islands, fanatical junior officers imposed draconian measures, executing scores of Okinawans as alleged spies or for disobeying army orders. The most notorious crime occurred on Tokashiki, where an army captain allegedly executed dozens of villagers and coerced more than 300 survivors into committing collective suicide.59

  The Thirty-second Army’s defense of Okinawa was also contr
oversial. Unsure of the Americans’ next objective, IGHQ transferred Okinawa’s strongest division to Taiwan and refused to replace it, citing the danger from U.S. submarines as justification for holding a division in Japan rather than sacrificing the unit at sea. This decision affected the navy’s Ten-gō plan, which called for a series of concentrated special-attack kamikaze aircraft to destroy the enemy at sea while ground forces repulsed them on the beaches. To execute the strategy, IGHQ and the Tenth Area Army on Taiwan ordered Okinawa’s airfields held at all costs to support the kamikaze operations. But the Thirty-second Army considered airpower a secondary factor and felt betrayed by IGHQ’s refusal to send reinforcements to defend airfields. As a consequence, the Thirty-second Army unilaterally abandoned the airstrips to contract its defensive perimeter.60 U.S. Army and Marine landings on April 1, 1945, met little resistance, quickly overran the airfields, and moved inland, where they eventually confronted the main Japanese defensive belts in a grim war of attrition.

  Two days later, the emperor questioned the decision to abandon the airfields; IGHQ and the Tenth Area Army then ordered a counterattack to retake them and destroy the invaders at the waterline. Disagreement among the Thirty-second Army’s senior staff officers nullified that order, and thereafter the ground battle degenerated into a brutal slugging match. U.S. losses in the two months of back-and-forth fighting totaled more than 65,000 casualties (26,000 nonbattle losses). According to Japanese sources, military losses were 65,000 killed, but 100,000 civilians died in the battle, including approximately 24,000 Okinawans impressed into service and thrown into battle with little training or equipment.61 The staggering civilian losses suggest the savagery of the fighting and the Japanese army’s indifference to their fate.