Table 11.2. Regular Army and Reserve Troop Numbers, 1937–1945
Year
Regular Army
Reservists
Total
1937
336,000
594,000
930,000 (63%)
1938
590,400
511,600
1,102,000
1939
804,400
391,600
1,196,000 (32%)
1940
910,000
380,000
1,290,000 (29%)
1941
1,032,500
992,500
2,025,000
1942
1,087,000
1,248,000
1,208,000
1943
1,502,000
2,295,000
2,750,000 (54%)
1944
2,118,400
1,641,600
3,760,000
1945
2,444,000
3,506,000
5,950,000 (58%)
Note: All figures exclude army air force personnel, whose numbers rose from 5,000 in 1937 to 74,500 in 1945. % = percentage of reservists.
Source: Rikusen gakkai, ed., Kindai sensōshi gaisetsu Shiryō hen, 36, table 2–1-9.
In January 1943, British Brig. Orde Wingate opened a daring four-month campaign behind Japanese lines that proved troops could maneuver in large units regardless of the inhospitable terrain. Two months later, Mutaguchi assumed command of the Fifteenth Army and, impressed by Wingate’s feat and a vociferous advocate of the offensive, pressed for an invasion of India to preempt future Allied thrusts by destroying the enemy bases. His superior, Gen. Kawabe Masakazu, commanded the Burma Area Army, and both officers had been involved in the 1937 Marco Polo Bridge Incident. When Kawabe was noncommittal about invading India, Mutaguchi made the emotionally clinching appeal that because they were the combination that had started the Greater East Asia War they should be the ones to end it at Imphal.28
Senior staff officers in echelons from the Fifteenth Army to IGHQ opposed Mutaguchi, who reacted by transferring his chief logistician for criticizing the plan. Tōjō considered the whole thing very risky, and the chief of the operations department thought it foolhardy. Nonetheless, on August 7 IGHQ authorized a limited counterattack to occupy key points on the west bank of the Chindwin River, followed by an advance toward Imphal to draw British forces into a battle of attrition. IGHQ issued no detailed guidance, deferring to the custom of not placing excessive restrictions on field commanders. Attached IGHQ liaison officers would provide clarifications, if needed. Mutaguchi ignored these nuances, planned a full-scale offensive to capture Imphal, and found an unlikely ally.
Japanese attempts to organize an Indian National Army (INA) from prisoners of the British Indian Army captured in Malaya and Burma proceeded fitfully until the summer of 1943, when the Indian revolutionary and nationalist Subhas Chandra Bose arrived at Singapore. Appointed commander of the INA, although without military rank, Bose revived the force. Ignorant of the terrible 1943 Bengal famine, a product of British administrative incompetence, Tokyo remained leery of unleashing Bose, but the fiery Indian nationalist convinced Mutaguchi that India was teetering on revolution and that the appearance of his Indian army would tip the balance.29
Lt. Gen. Joseph Stilwell, the Deputy Supreme Allied commander in Southeast Asia, was preparing to seize Myitkyina, a strategic road and rail junction in northern Burma halfway between his base at Ledo, India, and Kunming, China, as a first step to reopen the Burma Road. Chinese Central Army forces were also massing along the northeast Burma border, and in September 1943 Mutaguchi dispatched reinforcements to northern Burma.
On Christmas Day 1943 Japanese railroad construction units, using Allied POWs and indigenous forced laborers, had opened a 250-mile stretch of rail line from southwestern Thailand to Moulein in southern Burma, where it connected to the main line running north through Mandalay to Myitkyina. The lives of more than 15,000 Allied prisoners and ultimately 330,000 indigenous workers were taken during construction of the line, which only marginally improved the logistics capacity needed to attack India.30
This was of little concern to Mutaguchi, who decreed that the Fifteenth Army would live off the land and captured enemy supplies. For rations the army would herd Burmese cattle and sheep along its route of march; the slow-moving animals quickly ended up in soldiers’ cooking pots. Mutaguchi guaranteed a skeptical division commander that the British would surrender after the first Japanese volley. The 5th Air Division, depleted by transfers to New Guinea and the Philippines, was outnumbered four to one, but Mutaguchi assured doubters that air support was not all that necessary. Engineer units that were desperately needed to build roads and repair or build bridges to sustain the army had also been transferred to New Guinea.
After a meeting in late December 1943 with Mutaguchi, the Southern Army sent a senior officer to Tokyo to present the Fifteenth Army’s plan. As the officer was preparing to return to the front, he was summoned to the prime minister’s official residence where Tōjō, sitting in a steaming bathtub, fired a series of questions that recounted every major objection over the past six months. Assured these were taken care of, Tōjō endorsed the Imphal operation.31
In early January 1944 IGHQ ordered the Fifteenth Army’s three divisions to destroy British Commonwealth forces near Imphal and occupy strategic points in northeast Burma. Simultaneously, the Thirty-third Army, also three divisions, would drive Chinese forces from northeast Burma and prevent Allied operations from gaining ground in India. The Twenty-eighth Army (two divisions, with another in strategic reserve) would attack farther south on the Ayakab front to draw Allied reserves from Imphal.32
Mutaguchi set February 11, 1944 (National Foundation Day), to launch his offensive, which gave him one month to capture Imphal before the rainy season made large-unit movement almost impossible. IGHQ, however, postponed the operation because one division was still en route from China. By the time Mutaguchi began his advance on India on March 8, he was already well behind schedule.
Three days earlier Wingate’s glider-borne troops established an airhead in northern Burma that threatened Japanese rear area communications in north and central Burma in support of Stilwell’s and Chiang’s planned offensives. Mutaguchi was impervious to his commanders’ appeals to suspend his offensive until they crushed the expedition. Time was running out, and he pushed ahead—regardless of deteriorating logistics, the daunting terrain, and changing battlefield conditions. Two columns converged on Imphal from the south and the east while one division made a sweeping envelopment to seize Kohima, about 60 miles to the north, a move that would sever the Anglo-Indian line of communication by denying the British Fourteenth Army its main supply base and railhead, located about 30 miles northwest of Kohima.
Complicating the operation was a dysfunctional command. One division commander, Maj. Gen. Yamauchi Masafumi (15th Division), the only Imperial Japanese Army officer to graduate from the U.S. Army staff college at Fort Leavenworth, Kansas, was too westernized and sensitive for Mutaguchi, who labeled him a coward. Mutaguchi detested another division commander (31st Division), the hard-bitten combat veteran Lt. Gen. Satō Kōtoku, who reciprocated, leaving the two barely on speaking terms. A third division commander, Maj. Gen. Yanagida Kenzō (33d Division), a polished staff officer with no combat experience, regarded Mutaguchi as an idiot, and Mutaguchi openly called him a gutless bastard.33 With a command group that rivaled the worst combinations of the Russo-Japanese War, Mutaguchi set out to conquer India.
Despite the hardships of crossing the Arakan Range, by April 6 advance units of the 31st Division had occupied part of Kohima. Meanwhile, farther south, Yanagida’s 33d Division, lacking supplies and air cover, moved too slowly, so Mutaguchi sacked him and then relieved Yamauchi for reasons of ill health. By that time, the early onset of the rainy season, refined British tactics, and counterattacks ruine
d any chance to take Imphal. When Mutaguchi could not resupply Satō’s division, the fiery general unilaterally withdrew from Kohima on May 31, an unprecedented act by a general officer. Mutaguchi relieved him, but rather than court-martial Satō for desertion in the face of the enemy, which would expose Mutaguchi’s incompetence, the Burma Area Army declared Satō mentally unstable and shipped him back to Japan.34
By mid-May the general staff knew that Mutaguchi was in trouble, but no one, including Tōjō, would call off the operation. Kawabe was unwilling to act but hoped IGHQ would; years later Mutaguchi admitted that he should have abandoned the Imphal operation, but he could not bring himself to say so. IGHQ finally suspended the operation on July 4, but that was far too late. Soon afterward, Gen. William Slim began pursuit of the retreating, disorganized, and starving Fifteenth Army, having inflicted the worst military defeat the Japanese army ever suffered. The three divisions lost about 40,000 men killed, wounded, or missing. Perhaps another 36,000 support personnel perished during the grim retreat.
Logistics support was poor in all theaters and collapsed completely in some, like Burma. The late military historian Fujiwara Akira asserted that a majority of Japanese military deaths during the Asia-Pacific War resulted from starvation, not hostile action. Put differently, the army’s incompetence killed more Japanese soldiers than did the Allies. In China, where Fujiwara served, logistics was left to his infantry battalion rather than specialized construction and transportation units. Although a more conservative recent analysis lowers Fujiwara’s percentages, it generally concurs with his estimates.35
Besides wasting his army on an ill-considered adventure, Mutaguchi’s defeat left the Burma Area Army precariously overextended and vulnerable to Anglo-Indian, American, and Chinese counterthrusts along three fronts. Stillwell’s offensive into northwest Burma opened in May 1944 and in August captured Myitkyina. In conjunction with the offensive from the west, in mid-May fourteen Chinese divisions in Yunnan Province attacked from the east along the Burma border; by September they had reopened a portion of the Burma Road.
Japan’s southwest front was also crumbling. Minor landings along the New Guinea coast by Australian and American troops forced the Japanese to evacuate Lae in September 1943. The Allies then slowly advanced along the coastline as MacArthur built up and trained the U.S. Sixth Army. In late January 1944 the Sixth Army captured the Admiralty Islands, which isolated New Britain and the 80,000 soldiers and sailors at Rabaul, the major Japanese air and naval base. The general staff activated the Thirty-first Army on February 25 to defend the Carolines, Marianas, Palaus, and Iwo Jima, and reinforced those garrisons as well as forces in western New Guinea. Increasingly effective U.S. submarines mauled several convoys bound for the Marianas, leaving troops there short of equipment, reinforcements, and supplies.36
On April 22, MacArthur simultaneously executed three major amphibious landings 200 miles behind the Japanese Eighteenth Army’s coastal strongholds in eastern New Guinea. By seizing Hollandia, Netherlands New Guinea, MacArthur split Japanese army forces on New Guinea in two, cutting off the Eighteenth Army in eastern New Guinea and leaving the Second Area Army in western New Guinea waiting for the next blow to fall.
The Loss of the Marianas
Threatened on three fronts—Burma, the Central Pacific, and the Southwest Pacific—IGHQ turned on the main threat, the United States. Wherever the Americans next landed, the Japanese would force a decisive fleet engagement and then destroy the invaders along the beaches. On May 2 the general staff estimated that the Americans’ main axis of attack would be the New Guinea–Philippines line. The Marianas were too well defended—a division had just reinforced Saipan, which Tōjō boasted was “impregnable”—for the casualty-averse Americans to assault. The next day the commander of the Combined Fleet ordered the “A” Operation to destroy the U.S. fleet near the Palaus, about halfway between the southern Philippines and the Caroline Islands, a location chosen because it was within the operating radius of the Combined Fleet, then at anchor in the southern Philippines. If the Americans did strike the Marianas, Japanese carrier- and land-based aircraft would destroy them, but a shortage of fleet tankers precluded refueling at sea and hampered any surface fleet operations in the distant islands.37
MacArthur’s invasion of Biak, Schouten Islands, in late May became the focus of the Kon (All) Operation, a joint effort to reinforce the garrison, destroy American shipping, and isolate the invading ground forces. After two unsuccessful sorties, by early June Kon, backed by Japan’s two super battleships, was ready to destroy the Biak lodgment. Then intelligence reports reached IGHQ that imminent landings were expected in the Marianas. The navy immediately ordered the “A” Operation because the loss of the island chain would put Tokyo within range of American long-range bombers.
Carrier- and land-based aircraft flying from Guam, Tinian, and the Carolines engaged the U.S. invasion fleet on June 19–20, costing about 400 aircraft and three aircraft carriers but inflicting little damage in return. Two U.S. Marine divisions had assaulted Saipan on June 15, 1944, and, supported by a U.S. Army division, in bloody fighting with heavy casualties on both sides secured the island. The fall of the supposedly impregnable bastion forced the IGHQ war diarist to concede that Japan had lost the initiative; the nation would slowly descend into ruin unless a decisive battle reversed the situation by breaking the Americans’ will to fight. Lacking that, the only course was for all Japanese to emulate the Attu garrison’s example and fight to the death.38 The battle’s signature event, however, was a last-ditch suicide attack, launched in the early morning hours of July 7, that included perhaps 3,000 soldiers from various decimated units and some Japanese civilian settlers.
There were about 22,000 Japanese civilians on Saipan; many expected no mercy from the American invaders, and perhaps several hundred had committed suicide during and after the battle. Sensational propaganda, however, made it appear that thousands had chosen self-immolation over the humiliation of capture, but at least 15,000 civilians survived the fighting, and many of those killed were lost during the pre-invasion bombardment.39 Authorities made much of the civilians’ supposedly enthusiastic cooperation with the army to defend Saipan. This was obviously crude propaganda, but its underlying purpose was chilling: to convince Japanese civilians that they too were expected to fight to the bitter end to protect the homeland. In short, the army had imposed its standard of no surrender onto the civilian population to legitimize the notion of death before dishonor and collective suicide for all Japanese.
Saipan’s fall as well as the first B-29 air raid against the Japanese home islands on June 15 caused the collapse of Tōjō’s cabinet. Retired Gen. Koiso Kuniaki became the new prime minister and in early August replaced the liaison conference with the Supreme Council for the Direction of the War.40 Despite the grandiloquent title, the council was unable to provide strategic direction because the military refused to discuss operational matters in the presence of civilians, denied the prime minister information, and ignored Koiso’s recommendations.
Changing Operational and Tactical Doctrine
Defeats on the borders of India, the Marianas, and the Southwest Pacific ended the absolute defensive zone strategy. In its place, on July 24 IGHQ issued the Shō (Victory) plan to cover four contingencies—the defense of (1) the Philippines, (2) Taiwan and the Ryukyu Islands, (3) southern and central Japan, and (4) northern Japan and the Kurile Islands. Should the enemy attack any one of these sectors, the imperial army and navy would hurl their entire might against the invaders in a decisive battle. The next day Sugiyama and Umezu hedged that commitment by agreeing that the army would commit 70 percent of its resources against the Americans during 1944 to win a decisive battle, but retain 30 percent as the cadre to rebuild for a protracted war.41
The first meeting of the Supreme Council for the Direction of the War convened on August 19 in the emperor’s presence and authorized the Shō plans. Strategic guidance declared that no matter what Germany’s
fate after the Normandy landings in June 1944 and the Soviet summer offensive, the Japanese military intended to defend the homeland and prosecute war to the bitter end. The Allies’ desire to end war sooner rather than later in order to minimize their casualties and greater disruption of their national economies indicated weakness; and by marshaling available resources, preparing civilian morale for the impending air attacks from the Marianas and China, and using diplomacy—possibly enlisting the Soviet Union as an intermediary—Tokyo could reverse its unfavorable international situation.42
Emperor Hirohito (center) presides over the inaugural meeting of the Supreme Council for the Direction of the War on August 19, 1944. Seated to his right are the service chiefs of staff and their deputies. Prime Minister Koiso Kunaki is second on the emperor’s left. Others include War Minister Sugiyama Hajime (fifth from left) and Military Affairs Bureau chief Major General Satō Kenryō, last on the left. (Copyright © 2008 The Yomiuri Shimbun)
The army also reconsidered its counteramphibious doctrine. Prewar planners had never expected to be defending small Pacific atolls or islands, and the army subsequently adapted its standard tactical doctrine for the defense of a riverline as counteramphibious doctrine for island fighting. Units would defend along the waterline, weaken the invaders, and then destroy the survivors with a counterattack. Yamasaki’s charge at Attu and the fighting on Saipan exemplified the waterline defense.
Japan's Imperial Army Page 35