The Skies of China (Part 5): The Fall of Nanjing and the Shift to Strategic Bombing (1937–1941)
The capture of Nanjing and the withdrawal of the Chinese air force into the interior forced the Japanese command to alter its tactics and launch a massive campaign of strategic bombing against civilian and military targets. These long-range raids initially suffered from the limited range of fighter escorts, a vulnerability definitively resolved by the crushing debut of the new Mitsubishi A6M2 Reisen carrier fighters, which achieved absolute dominance over the skies of China.
NankingThecapture of Shanghaifreed up forces to concentrate the attack on Nanking, the capital of the Central Government. The advance proceeded along three axes. Penetrating from the north was the16th Divisioncommanded by Kesago Nakajima; the troops in the south were commanded by Gen. Yanagawa, and advancing from the east with the Shanghai veterans was Gen. Matsui. The lead Japanese units were 160 kilometers (99. 4 miles) from the city, and the greatest obstacle was the defensive perimeter in the Yangtze River delta, consisting of an in-depth chain of light pillboxes, bunkers, and heavy strongholds built under the supervision of German advisors. The Japanese breached the formidable-looking fortification zone incredibly easily and swiftly. On December 2, the Central Government succumbed to panic and showed a willingness to accept armistice conditions, but the Japanese generals had no interest in a political solution and continued their advance. Chiang Kai-shekrequested the German embassy to mediate contact with Prince Asaka and then retreated to Hankou. The flight of the politicians affected the morale of the 300,000 Chinese defenders, who then, along with a million civilian refugees, began fleeing upstream along the Yangtze. The ground units were provided air cover by elements of the 1st and 2nd Koku Sentai and tactical bombers of the 2nd Rengo Kokutai. Fighter Shotais of the 12th Kokutai and13th Kokutai, armed with thirty A5M1s, were designated to protect the bombers of theKanoya KokutaiandKisarazu Kokutaioperating from airfields around Shanghai and Beiping. The resistance of the Soviet volunteers was broken on December 2, when two Shotais led by Lt. Nango attacked a group of thirty Chinese fighters, shooting down thirteen of them (according to Chinese sources, only ten). During the evacuation of foreign legations, an incident also occurred involving the sinking of the gunboat USS Panay. On December 12, a formation of twelveD1A2sescorted by nineA5M1sfrom the aircraft carrierKagastruck. At the end of the 20-minute air raid, the river was covered with debris and overcrowded lifeboats rescuing survivors under the fire of the strafing escort fighters. Tokyo sent an official apology and an offer of compensation for damages and indemnities to the families of the wounded or killed passengers. The investigation led to the dismissal of the commander of the aircraft carrierKaga. The pilots emerged from the case untarnished; not even disciplinary proceedings were initiated against them, as they had done nothing other than flawlessly execute the command's orders. Col. Hashimoto also escaped with a clean slate, despite the fact that his artillerymen had badly battered the British gunboat HMS Ladybird a week earlier. On Friday, December 10, soldiers of Gen. Matsui's9th Divisionreached Nanking. Fighting still raged in the streets with defenders struggling to secure an escape route until Sunday. On Tuesday, Gen. Nakajima's units arrived. They were delayed by mass executions of prisoners captured in the suburbs and along the course of the Yangtze. Following the orders of Prince Asaka, the soldiers began searching for hidden Chinese, gathered the detainees on the riverbank, and executed them in the evening. Bestial violence engulfed the entire city and continued until December 23, when it culminated. Naval aviation statistics: 192 aircraft conducted 70 air raids against Nanking, during which 560 tons of bombs were dropped. Among the fighters, the 13th Kokutai performed the best. The Japanese brutality in Nanking did not meet their expectations, and instead of breaking the will to fight, a wave of anger and desire for revenge flooded the Chinese military. Thousands of volunteers began joining the army, replenishing the sustained losses. Chiang Kai-shek'sair force retreated to Nanchang, located 600 kilometers (372. 8 miles) southwest of Shanghai, and to Hankou. By escaping beyond the range of Japanese fighters, it thus gained the necessary breathing space for reorganization and regeneration of forces. The self-confidence of the Soviet volunteers, who had hitherto looked down on their Chinese counterparts, also suffered from the Nanking debacle. The realization that the vaunted Polikarpov aircraft lagged behind the globally disregarded production of the Empire of the Rising Sun did not exactly align with the declarations of the political commissars. The Mitsubishi A5M1 andA5M2surpassed theI-15bisandI-16in agility during both vertical and horizontal maneuvers, and they eliminated the advantage of the Soviet fighters' heavier armament and armor through the robustness of their design, which could withstand even severe damage. The delivery of 180 I-15bis fighters at the beginning of 1938 led to a more significant revival of Chinese aviators' activity. The tactic of throwing themselves into individual dogfights had little prospect of success. Therefore, they opted for a simple but effective combat method. They focused on the command aircraft of individual Japanese formations, which they attacked from the rear with a significant altitude advantage. In a steep dive utilizing high speed, they aimed at the selected victim and fired at the cost of minimal time for targeting and the actual shooting. Before the Japanese realized the danger threatening them, the deed was done. By doing this, the Chinese gave the more experienced imperial pilots no chance to initiate a maneuvering dogfight, in which they would certainly have perished. With their hit-and-run tactics, they soon deprived the imperial aviation of a number of experienced pilots. The crews of theSB-2bombers performed no less proficiently. They gradually undertook some one hundred and twenty daring raids against troop staging areas in occupied territories and against supply hubs. 1938After reaching Nanking, the Daihon'ei (Imperial General Headquarters) temporarily halted the advance on the northern and central sectors of the front. On one hand, it wanted to stabilize the achieved successes and use the pause to reorganize forces before the spring offensive. The collapse of the hastily cobbled-together operations from the beginning of the campaign served as a warning. The cost of the defeat of Lt. Gen. Itagaki's 5th Motorized Division at the Pingxingguan Pass, which cost the Japanese three thousand dead, ultimately proved too small to influence the existing, all-too-frivolous approach of the staff officers toward the creation and scheduling of operational plans. The main goal of the spring offensive was to link the northern and central fronts, followed by the occupation of important military-political and economic centers in eastern China, including the economic potential of the Wuhan tri-city area. The Kanto Gun launched the attack on Xuzhou from staging areas around Jinan and Qingdao with units of the 5th Motorized Division, which was looking for an opportunity to avenge its suffered defeat, reinforced by infantry regiments of the10th Division. The operation was supported by one hundred and forty aircraft of the Shina Dokuritsu Hiko Shudan, fulfilling the tasks of direct support for ground forces. Units advancing from Nanking were supported by around a hundred machines of the 2nd Rengo Kokutai, while seventy bombers of the Kisarazu and Kanoya Kokutai struck the Chinese rear. The campaign began with air raids by army bombers on bases near the cities of Xi'an, Xianyang, Kaifeng, and Luoyang. The surprise attack ended with fatal consequences for the Kuomintang. Left on the airfields after the attackers' departure were the smoldering wrecks of the vast majority of the aircraft concentrated there and the demolished facilities of military installations. The first serious resistance occurred on January 30 when the 6th Hiko Daitai conducted a raid on Luoyang. The fighter defense climbing toward the bombers was attacked by two Ki-10 Chutais of the 2nd Hiko Daitai; the battle proceeded inconclusively before a third Chutai entered it. For the loss of one aircraft, the Japanese claimed twelve I-15s. In February, the army aviation carried out only a few isolated actions. A more significant revival occurred with the arrival of early spring. On March 8, bombers of the 6th Hiko Daitai, in cooperation with nine Ki-10s from the 2nd Chutai of the 2nd Hiko Daitai, attacked Xi'an. Three of the ChineseGloster Gladiatorsfell victim to the attackers. Between February and May, only six major clashes occurred, in which the primary participant was exclusively Maj. Tamiji Teranishi's 2nd Hiko Daitai. The remaining two fighter Hiko Daitais, operating in the direction of the main thrust from the north, were utilized in ground-attack strikes against heavily fortified pockets of resistance. On April 3, the first NakajimaKi-27 Type 97 Model 1Asarrived at the front. The 1st Chutai received the first three machines. On April 10, they underwent their baptism of fire. A Japanese formation consisting of three Ki-27s and four Ki-10s of the 1st Chutai and eight Ki-10s of the 2nd Chutai attacked thirty Chinese fighter aircraft over Kaifeng. The overall tally of the engagement – twenty-four destroyed I-15s, for which the 2nd Hiko Daitai received a special commendation from the Kanto Hikotai. Nakajima Ki-27 Type 97 Model 1AThe new fighters gradually reached the59th,4th,5th,11th,24th, and13thHiko Sentais, while the 2nd and 3rd Chutais of the64th Hiko Sentai(formerly the 2nd Hiko Daitai) waited until October and the beginning of 1939. Similarly, newKi-15sarrived at the 16th and 18th Dokuritsu Dai Shijugo Chutais (Independent Reconnaissance Chutais). The newKi-32light bombers were given to the27th,45th, and75thHiko Sentais, and theKi-30swere received by the31stand90thHiko Sentais. The60th Hiko SentaireceivedKi-21-Iaheavy bombers, while ItalianFiat BR. 20 Cicognastaxied onto the hardstands of the12thand98thHiko Sentais. Along with the modernization of equipment, an organizational change took place in August 1938, when the existing aviation regiments – Hiko Daitai and Hiko Rentai – were replaced by the Hiko Sentai and Hikojo Daitai, which also received new numbering. A Hiko Sentai usually consisted of three to four Chutais. A Hikojo Daitai was a ground crew unit taking care of the functioning of the aviation component, usually numbering 200 to 250 soldiers. Within the framework of expanding the numerical strength of the army aviation, many independently operating squadrons also underwent reinforcement to regimental strength. In the first week of April 1938, the advance of the 10th Infantry Division ground to a halt and ended in encirclement at Tai'erzhuang. Around them, tanks of the 5th Motorized Division, supported by heavy artillery, attacked the Kuomintang grip in vain. The Japanese suffered heavy losses: 30,000 dead, wounded, and captured. Gen. Li Zongren, however, failed to exploit the victory to save Xuzhou and, instead of pressing the attack, disengaged from the enemy. The city fell on May 19, despite the floods caused by the breaching of the dikes on the Yangtze, which were intended to slow the Japanese advance. Thousands of peasants fell victim, but the attackers did not slow down. The continuing attack was directed against Anqing and Wuhan. The operation, which lasted from May to October, was executed by 240,000 soldiers, 180 tanks, 350 aircraft, and several river gunboats along two main axes – the Yangtze River valley and from the direction of Xuzhou. Over the course of five months, the Chinese and Soviet volunteers carried out some 3,281 offensive actions, including a leaflet raid by two Martin 139Ws on Nagasaki, and dropped a total of 519 tons of bombs. Despite their attacks, the advance of the 1st Division along the banks of the Yangtze did not halt. Between June 14 and July 28, the fast SB-2s undertook around forty ground-attack raids. In one instance, anti-aircraft defenses shot down a complete five-aircraft formation. Between August and October, the Japanese conducted 5,294 operations on the main axis. The army aviation, in cooperation with the air forces of the Shina Homen Kantai, neutralized 202 Chinese aircraft and severely damaged 112. By occupying the tri-city area on October 27, 1938, the Japanese severed the sole railway connection traversing China from north to south, thus splitting the hitherto compact Kuomintang army into two parts. In a relatively short time, the Japanese thus gained control over the most economically developed part of the country. The decision of what to do next, with the troops standing on the borders of the Chinese interior lacking infrastructure and reliable communications and facing the prospect of problematic troop supply, was attempted to be resolved by politicians, butChiang Kai-shekhad to reject a humiliating peace if he did not want to lose foreign sympathy and aid, as well as for domestic political reasons regarding his own people following the mass atrocities in Nanking. Fearing a loss of face, the Japanese were compelled to continue the fight. One solution was offered by the theory of General Douhet. At this moment, the air war entered its second stage, and the focus of deployment shifted from tactical raids supporting troops to aerial terror against cities in the rear. From February onwards, the naval aviation's activity in the spring campaign of 1938 concentrated the efforts of the 1st and 2nd Rengo Kokutai on liquidating defensive positions around Xuzhou and Anqing and against airfields in the vicinity of Nanchang and Hankou. The considerable distance of the targets caused problems for the fighter escort, as they lay at the limit of the A5M fighters' range. A partial solution was proposed by Minoru Genda, suggesting that an advanced airfield would serve the escorting fighters for layovers and refueling. Supplies to the Guangde airfield were transported by air. The heavy losses in the autumn of 1937 crippled the activities of the G3M1 and G3M2 bombers, necessitating the deployment of reserve machines – the olderG2H1s. They operated in combat between September 30 and October 24, after which they finished their service providing aerial resupply of the advanced airfield for escort fighters. Due to production difficulties with the A5M, two foreign types were ordered: the GermanHeinkel He 112 B-0and the AmericanSeversky 2PA-B3. The He 112 operated under the designationA7He1, and the Seversky 2PA-B3 as theA8V1. Both failed to meet the expectations placed on them, and after a brief combat deployment as fighters, they were transferred to tactical reconnaissance, where they operated until 1942. A solution was not brought until theA5M4type with extended range. On February 18, Chinese I-15bis and I-16s dealt a heavy defeat to Japanese bombers and their four escorting A5Ms. The tables turned on February 25, which became one of the naval aviation's most successful days in 1938, when a formation of 35 bombers and 18 A5M fighters claimed 42 confirmed and 13 probable victories, losing only three fighters. The reality was indeed more sober, but superiority was clearly on the Japanese side. The engagement also had other consequences. Lt. Taguma's machine, identification number 4-122, fell into Chinese hands in an airworthy condition. Following a series of evaluation flights, the written report of whichClaire L. Chennaultsent to the USA, the aircraft was handed over to the Soviets. The captured aircraft was ferried by Grigory Zakharov, who describes in his book how he was forced by sabotage – a sugar cube in the fuel tank – into an emergency landing in the mountains during the flight to the USSR, thus damaging the aircraft. It subsequently arrived at its destination disassembled. Aircraft carriers operated along the coast of central China, and their aircraft exclusively supported the ground actions of the army and naval infantry. On April 29, an air raid on Wuhan turned into a ferocious battle with the Chinese and Soviet volunteers. According to Chinese sources, for the loss of twelve fighters, they destroyed eleven Japanese fighters and ten bombers. From April until July 19, the naval aviation bombed Hankou and Nanchang almost every day, but battles akin to the one on April 29 remained exceptions. From April 13, air raids against the city of Canton began. During an air raid on May 28, 1938, some six hundred residents of Canton perished and nine hundred suffered injuries. The raid provoked Chinese protests at the League of Nations. Smaller groups of aircraft attacked the city incessantly until October 21, when it capitulated. With the onset of autumn, the intensity of the Kuomintang's resistance steadily waned, and classic aerial dogfights virtually ceased. Ground operations also ground to a halt; only limited tactical raids against selected targets in the immediate vicinity for the purpose of replenishing supplies maintained Japanese activity. 1939/40From January 1939, the Chinese campaign entered another phase, characterized primarily by the passive behavior of Japanese ground armed units. The army consolidated its conquered positions and devoted all efforts to constructing a buffer zone that would allow them to capitalize on the achieved successes. A more significant change did not occur until the autumn. In November, the army launched an advance on Nanning. The strong resistance of Chinese aviation units forced the 14th Kokutai to combine its forces with the 12th Kokutai and the carrier air group from the Akagi. This superiority forced the Kuomintang to retreat. Nanning capitulated at the end of December. The period of relative calm, however, did not apply to the Japanese aviation, which attacked the Chinese rear. Strategic bombing took place in five successive waves. The first, from December 1938 to February 1939, included twenty attacks by the 1st Hikotai against Chongqing. The main burden was borne by the 60th, 12th, and 98th Sentais. After three months, losses reached such heights that they completely crippled the operational capability of these regiments. Afterward, they were transferred to Manchuria. The second operation was called off as a result of the fighting at Nomonhan, which tied down a considerable portion of the army aviation forces. Only the 3rd Hikoshidan operated on the Chinese front. The main burden was assumed by the naval aviation. And thus, bombs continued raining down on Chongqing. The third operation took place between May and September 1939 and was among the most devastating of the entire Chinese conflict period. Twenty-two operations, encompassing two hundred air raids, were directed against the capital. The naval aviation continued its systematic air raids until May 1942, when the aviators of the American Volunteer Group forced the attackers to jettison their bombs outside the city. Around 60,000 residents of this city perished as a consequence of the bombing. Over thirty-four months, G3M2s conducted 410 long-range raids. Initially, the formation consisted of eighteen, at most thirty-six bombers; by the summer of 1940 it was already ninety machines, and a year later formations of one hundred and thirty bombers were commonplace. From late 1938 to August 1940, there were only eighty large-scale engagements with Chinese anti-aircraft defenses, but minor battles accompanied almost every raid. On October 3, 1939, during a daring Kuomintang raid against the Japanese base at Hankou, in addition to the destroyed machines, Admiral Tsukahara also lost his life. During the Japanese retaliation on November 4 against the city of Chengdu, the commander of the 13th Kokutai, Admiral Kikuji Okuda, was shot down. On November 18, Chinese forces launched an advance on Changsha. The mass of attacking troops was supported by one hundred and fifteen aircraft of the 3rd, 4th, and 5th Pursuit Squadrons, the 6th Bomber Regiment, and the 18th Reconnaissance Squadron. The crews undertook twelve major sorties against Japanese airfields and supply lines. They destroyed eleven Japanese aircraft in the air and fifteen on the ground. Despite stiff resistance from the imperial naval infantry and army, the Chinese offensive continued until March 1940, when the first Kuomintang units penetrated Nanning and liberated it. The naval aviation struck on December 30, shooting down fourteen Chinese fighters for the loss of one machine. The same scenario repeated on January 10, when the ratio was sixteen to zero in favor of the A5M. The fourth operation took place from spring to autumn 1940, peaking from June to August. The priority was destroying the remnants of the Chinese air force and breaking the will to resist by bombing inland cities. The army aviation struck first with Ki-21-Ias of the 60th Sentai in a prelude on April 29, 1940. By October 10, the 60th Sentai had conducted twenty raids against the capital and its surroundings. From May, the naval aviation joined in with the forces of the 1st and 2nd Rengo Kokutai, which by September undertook 3,714 raids against the interior, during which a mere nine aircraft were lost and 297 damaged. Over 40,000 soldiers and civilians fell victim to the attacks. Following the September combat debut of the new A6M2 Reisen in the ranks of the navy, the Chinese sky unequivocally belonged to the Japanese. The necessary reorganization of Chinese anti-aircraft defenses brought the departure of the Soviet contingent and the start of its replacement by American volunteers withP-40Baircraft. By the end of 1940, the Chinese air force had only 65 aircraft on the frontline. A comparison of fighter losses – the loss of twenty A5Ms against 230 Chinese machines – clearly showed who was winning the aerial dogfights. The brunt of the Japanese losses, however, was borne by attack aircraft and heavy bombers, with half succumbing to Chinese fighters and the remainder divided between anti-aircraft artillery and other causes (weather, accidents. . . ). Unofficial sources also speak of raids where bomber losses exceeded 10%, a severe consequence of raids beyond the range of fighter escorts. A solution was sought in extending the range of the A5M and gradually modernizing bombers, but the definitive solution was not brought until the entry of theA6M2onto the scene, which with its phenomenal range of over 1,800 kilometers (1,118. 5 miles) spelled the end for active Chinese anti-aircraft defenses. After the Reisens swept aside the Chinese fighters, the only remaining Chinese defense was anti-aircraft guns. A brief pause was provided by the invasion of army detachments into French Indochina in late September 1940. Following the French capitulation, the majority of units operating in the central sector of the Chinese front relocated to the modern airfields near Tonkin and commenced air raids against China from the new deployment. The Reisens of the 12th Kokutai controlled the central sector of the front, and the 14th Kokutai controlled the entire area of Guangxi province and the northern part of French Indochina. Aerial dogfights became a rarity, and if they occurred, they were one-sided affairs dictated by the Japanese. Air supremacy allowed the withdrawal of G3M2 bombers from the front in October; their crews rested on Formosa and the Japanese home islands until April 1941. Aircraft from carrier decks engaged more intensively primarily during the Guangdong operation, but otherwise, aside from low-level activity during the blockade of the Chinese coast, they devoted themselves mainly to training. 1941In April, the reorganized and modernizedGenzanand Mihoro Kokutai relocated to central and northern China as the initial wave launching the fifth aviation operation. In July, they were reinforced by the Kanoya, Takao, and 1st Kokutai armed with the newG4M1 Model 11s. Operating in the north of French Indochina was the 3rd Kokutai; in addition to air raids against China, its machines engaged in reconnaissance of military installations in the Philippines and the Malay Peninsula. Mitsubishi G4M1 Model 11The 1941 season began with the traditional air raid on Chongqing and against Chengdu. Considerable attention was focused on supply routes, railways, depots, and bridges on the supply route to the USSR through Sichuan province. The army aviation was involved only with the heavy bomber machines of the 60th Sentai and elements of the 59th and 90th Sentais. In northern China, the army's 45th Sentai was also engaged withKi-48-Ialight bombers. Following the replenishment of losses suffered at Nomonhan, army Ki-27 fighters were received by the 50th Sentai (1940), 87th Sentai (March 1941), 206th Sentai, 85th Sentai, 54th Sentai, 70th Sentai, and 144th Sentai. During August 1941, the 59th and 64th Sentais received the newNakajima Ki-43-I Hayabusa, but by then most army units were being transferred to French Indochina in preparation for the Malayan campaign, and so the burden of fighter operations on the Chinese front fell squarely on the shoulders of the naval aviators of the Shina Homen Kantai. On the Chinese front, aerial dogfights continued to be only a sporadic affair, while losses caused by anti-aircraft artillery began to mount. In the summer, several attempts at aerial resistance occurred, but they were mercilessly crushed. With the arrival of autumn and preparations for the war in the Pacific, military operations in China lost their priority status, and the navy initiated an extensive transfer of units to Japan, French Indochina, and Formosa. During this period, the successful 12th and 14th Kokutais were disbanded, and their battle-hardened veterans dispersed to other units, which could thus benefit from their experience. After the departure of the navy's land-based aviation units, the responsibility for continuing the offensive against the Chinese interior passed to the army aviation, which, while maintaining this pressure, simultaneously shifted its main forces south against Hong Kong and Malaya. American volunteers were preparing to enter the Chinese scene, thereby altering the total Japanese air supremacy that had prevailed until then. The Japanese were winning battle after battle, but the Chinese were not preparing to capitulate. Strategic bombing of military-political targets and economic centers in the spirit of Douhet's theories brought no positive results other than the suffering of the civilian population; rather, it merely intensified the will to resist and the desire for retribution. The battles in China provided both aviation branches of the Japanese Empire with an opportunity for perfect training and the testing of modern equipment and deployment tactics. In addition, the army aviation underwent a harsh lesson during the battles against the USSR, which could not be compared to the operations against a weak China. Many shortcomings were revealed. Formulaic management of operations and a tendency to underestimate the enemy, along with insufficient cooperation between fighters and bombers, led to painful losses. The importance of fighter escorts was paid for by the losses of unprotected bombers. The Japanese, however, were given ample time to learn and implement necessary changes, so their air force opened the war in the Pacific from the position of battle-hardened veterans; the cost of losses and wear and tear on equipment manifested itself in missing reserves for a protracted conflict, the risks of which were warned of by Admiral IsorokuYamamoto– but that is another chapter. In the meantime, the judgment of Americans and Europeans regarding Imperial Japan was clouded by prejudices and distorted press reports. Only Soviet Russia became acquainted with the harsh reality of the quality of Japanese pilots and aircraft, something taken away primarily by direct participants in the fighting in China, atKhasan, andNomonhan, because the official version was dictated by the propaganda of the Communist Party as absolute Soviet superiority, thus only playing into the West's distorted conception of the combat performance of the Japanese war machine. Sources:Josef Novotný, Kanto Gun (History of the Kwantung Army)Henry Sakaida, Aces of the Rising Sun 1937-1945Robert B. Edgerton, Warriors of the Rising SunLubomír Vejřík, Rise and Fall of the Eagles of Nippon 1931-1941Georgy Zakharov, I Am a Fighter Pilot