Battle of Nanking
The Battle of Nanking was fought in early December 1937 during the Second Sino-Japanese War between the Chinese National Revolutionary Army and the Imperial Japanese Army for control of Nanjing, the capital of the Republic of China.
Following the outbreak of war between Japan and China in July 1937, the Japanese and Chinese forces engaged in the vicious three-month Battle of Shanghai, where both sides suffered heavy casualties. The Japanese eventually won the battle, forcing the Chinese army into a withdrawal. Capitalizing on their victory, the Japanese officially authorized a campaign to capture Nanjing. The task of occupying Nanjing was given to General Iwane Matsui, the commander of Japan's Central China Area Army, who believed that the capture of Nanjing would force China to surrender and thus end the war. Chinese leader Chiang Kai-shek ultimately decided to defend the city and appointed Tang Shengzhi to command the Nanjing Garrison Force, a hastily assembled army of local conscripts and the remnants of the Chinese units who had fought in Shanghai.
In a five-week campaign between November 11 and December 9, the Japanese army marched from Shanghai to Nanjing at a rapid pace, pursuing the retreating Chinese army and overcoming all Chinese resistance in its way. The campaign was marked by tremendous brutality and destruction, with increasing levels of atrocities committed by Japanese forces against the local population, while Chinese forces implemented scorched earth tactics to slow the Japanese advances.
Nevertheless, by December 9 the Japanese had reached the last line of defense, the Fukuo Line, behind which lay Nanjing's fortified walls. On December 10 Matsui ordered an all-out attack on Nanjing, and after two days of intense fighting Chiang decided to abandon the city. To prevent the Nanjing defenders from being surrounded and annihilated by the enemy, Chiang Kai-shek considered ordering a retreat at noon on the 11th. He then instructed Gu Zhutong, then in Jiangbei, to convey this message by phone to Tang Shengzhi. Gu instructed Tang to cross the river north that night and order the defenders to break out if necessary. Tang Shengzhi, having previously advocated for a firm hold, feared the potential liability of a sudden withdrawal. Therefore, he demanded that the Supreme Commander's intentions be clearly conveyed to the defending generals before any withdrawal could be allowed. Tang Shengzhi, a man of urgency, insisted on receiving Chiang Kai-shek's personal order before retreating. That evening, Chiang Kai-shek indeed telegraphed Tang Shengzhi: "If the situation cannot be sustained, you may retreat if necessary to regroup and prepare for a counterattack." Tang ordered his men to launch a concerted breakout of the Japanese siege, but by this time Nanjing was largely surrounded and its defenses were at the breaking point. Most of Tang's troops collapsed in a disorganized rout. While some units were able to escape, many more were caught in the death trap the city had become. By December 13, Nanjing had fallen to the Japanese.
Following the capture of the city, Japanese forces massacred Chinese prisoners of war, murdered civilians, and committed acts of looting, torture, and rape in the Nanjing Massacre. Though Japan's victory excited and emboldened them, the subsequent massacre tarnished their reputation in the eyes of the world. Contrary to Matsui's expectations, China did not surrender and the Second Sino-Japanese War continued for another eight years, leading to the surrender of Japan.
Background
Japan's decision to capture Nanjing
The conflict which would become known as the Second Sino-Japanese War started on July 7, 1937, with a skirmish at Marco Polo Bridge which escalated rapidly into a full-scale war in northern China between the armies of China and Japan. China, however, wanted to avoid a decisive confrontation in the north and so instead opened a second front by attacking Japanese units in Shanghai in central China. The Japanese responded by dispatching the Shanghai Expeditionary Army, commanded by General Iwane Matsui, to drive the Chinese Army from Shanghai. Intense fighting in Shanghai forced Japan's Army General Staff, which was in charge of military operations, to repeatedly reinforce the SEA, and finally on November 9 an entirely new army, the 10th Army commanded by Lieutenant General Heisuke Yanagawa, was also landed at Hangzhou Bay just south of Shanghai.Although the arrival of the 10th Army succeeded at forcing the Chinese Army to retreat from Shanghai, the Japanese Army General Staff had decided to adopt a policy of non-expansion of hostilities with the aim of ending the war. On November 7 its de facto leader Deputy Chief of Staff Hayao Tada laid down an "operation restriction line" preventing its forces from leaving the vicinity of Shanghai, or more specifically from going west of the Chinese cities of Suzhou and Jiaxing. The city of Nanjing is roughly west of Shanghai.
However, a major rift of opinion existed between the Japanese government and its two field armies, the SEA and 10th Army, which as of November were both nominally under the control of the Central China Area Army led by SEA commander Matsui. Matsui made clear to his superiors even before he left for Shanghai that he wanted to march on Nanjing. He was convinced that the conquest of the Chinese capital city of Nanjing would provoke the fall of the entire Nationalist Government of China and thus hand Japan a quick and complete victory in its war on China. Yanagawa was likewise eager to conquer Nanjing and both men chafed under the operation restriction line that had been imposed on them by the Army General Staff.
On November 19 Yanagawa ordered his 10th Army to pursue retreating Chinese forces across the operation restriction line to Nanjing, a flagrant act of insubordination. When Tada discovered this the next day he ordered Yanagawa to stop immediately, but was ignored. Matsui made some effort to restrain Yanagawa, but also told him that he could send some advance units beyond the line. In fact, Matsui was highly sympathetic with Yanagawa's actions and a few days later on November 22 Matsui issued an urgent telegram to the Army General Staff insisting that "To resolve this crisis in a prompt manner we need to take advantage of the enemy's present declining fortunes and conquer Nanking... By staying behind the operation restriction line at this point we are not only letting our chance to advance slip by, but it is also having the effect of encouraging the enemy to replenish their fighting strength and recover their fighting spirit and there is a risk that it will become harder to completely break their will to make war."
Meanwhile, as more and more Japanese units continued to slip past the operation restriction line, Tada was also coming under pressure from within the Army General Staff. Many of Tada's colleagues and subordinates, including the powerful Chief of the General Staff Operations Division Sadamu Shimomura, had come around to Matsui's viewpoint and wanted Tada to approve an attack on Nanjing. On November 24 Tada finally relented and abolished the operation restriction line "owing to circumstances beyond our control", and then several days later he reluctantly approved the operation to capture Nanjing. Tada flew to Shanghai in person on December 1 to deliver the order, though by then his own armies in the field were already well on their way to Nanjing.
China's decision to defend Nanjing
On November 15, near the end of the Battle of Shanghai, Chiang Kai-shek convened a meeting of the Military Affairs Commission's Supreme National Defense Council to undertake strategic planning, including a decision on what to do in case of a Japanese attack on Nanjing. Here Chiang insisted fervently on mounting a sustained defense of Nanjing. Chiang argued, just as he had during the Battle of Shanghai, that China would be more likely to receive aid from the great powers, possibly at the ongoing Nine Power Treaty Conference, if it could prove on the battlefield its will and capacity to resist the Japanese. He also noted that holding onto Nanjing would strengthen China's hand in peace talks which he wanted the German ambassador Oskar Trautmann to mediate.Chiang ran into stiff opposition from his officers, including the powerful Chief of Staff of the Military Affairs Commission He Yingqin, the Deputy Chief of Staff Bai Chongxi, the head of the Fifth War Zone Li Zongren, and his German advisor Alexander von Falkenhausen. They argued that the Chinese Army needed more time to recover from its losses at Shanghai, and pointed out that Nanjing was highly indefensible topographically. The gently sloping terrain in front of Nanjing would make it easy for the attackers to advance on the city, while the Yangtze River behind Nanjing would cut off the defenders' retreat.
Chiang, however, had become increasingly agitated over the course of the Battle of Shanghai, even angrily declaring that he would stay behind in Nanjing alone and command its defense personally. But just when Chiang believed himself completely isolated, General Tang Shengzhi, an ambitious senior member of the Military Affairs Commission, spoke out in defense of Chiang's position, although accounts vary on whether Tang vociferously jumped to Chiang's aid or only reluctantly did so. Seizing the opportunity Tang had given him, Chiang responded by organizing the Nanjing Garrison Force on November 20 and officially making Tang its commander on November 25. The orders Tang received from Chiang on November 30 were to "defend the established defense lines at any cost and destroy the enemy's besieging force".
Though both men publicly declared that they would defend Nanjing "to the last man", they were aware of their precarious situation. On the same day that the Garrison Force was established Chiang officially moved the capital of China from Nanjing to Chongqing deep in China's interior. Further, both Chiang and Tang would at times give contradictory instructions to their subordinates on whether their mission was to defend Nanjing to the death or merely delay the Japanese advance.