The Second Sino-Japanese War

chinese civil war

Nationalist soldiers train on machine guns during the Chinese Civil War

The Second Sino-Japanese War (1937-45) had a significant impact on the course of the Chinese Revolution. Known in China as the War of Chinese People’s Resistance Against Japanese Aggression, this conflict was catastrophic for the Chinese people, causing up to 20 million casualties. It also had serious political repercussions for the Guomindang (GMD) and the Chinese Communist Party (CCP). Japan’s invasion of China in the early 1930s and the ensuing war were the culmination of decades of antagonism between the two nations. The political and economic development of Japan stood in stark contrast to that of China. The Meiji Restoration of the late 19th century had propelled Japan into the modern world. The Japanese had tapped had Western knowledge to develop an industrialised economy. Japan’s military, once a barefoot army of samurai, was now a well trained Westernised armed force, equipped with modern weapons. Its government was dominated by militarists and expansionists who sought to make Japan an Asian imperial power.

In August 1894 Japan went to war with China over control of the Korean peninsula. The conflict ended with a Japanese victory in a little over eight months, despite the Japanese being greatly outnumbered by Qing forces. In the April 1895 treaty the Chinese ceded control of the Liaodong peninsula, west of Korea, and the island of Taiwan. Six years later, following the disastrous Boxer Rebellion, the Japanese won the right to station troops in eastern Manchuria, which gave them a military stronghold on the Chinese mainland. China’s military weakness and the collapse of the Qing in 1911 allowed Japan to expand its sphere of influence. In 1915 the Japanese government issued Chinese president Yuan Shikai with a set of territorial and concessional demands, which Shikai had no choice but to accept. In September 1931 an incident in Mukden, Manchuria, provided the Japanese with the pretext for a full military invasion of Manchuria. Once established there, the Japanese set up the puppet state of Manchukuo and installed the last Qing emperor, Puyi, as its ineffectual head of state. In May 1933 Jiang Jieshi (Wade-Giles: Chiang Kai-shek), who was more concerned with fighting the communists, offered little resistance to the Japanese and signed the Tanggu Truce, effectively recognising the legitimacy of the Manchukuo puppet state.

sino-japanese war

The former Qing emperor Puyi during his ‘reign’ over Manchukuo.

A full scale war began in July 1937 following an incident near the Marco Polo Bridge in Wanping, near Beijing, when Japanese troops opened fire on local soldiers. A brief ceasefire was signed but both sides increased military numbers in the region. When the Japanese invaded in late July, the GMD and CCP formed a shaky alliance dubbed the Second United Front. The GMD armies attempted to resist the invasion but were quickly overcome by the technological supremacy and preparedness of the Japanese. China’s underdeveloped industries were incapable of supplying munitions or engineering with quickly or in sufficient quantities; the Chinese military had no tanks and only a few aircraft. The first phase of the war was a blitzkrieg of Japanese victories, as their forces moved swiftly along China’s east coast. Almost a half-million Japanese troops moved against Shanghai, Nanjing and other locations in mainland China, while Japanese military planes bombarded regions where their foot-soldiers could not penetrate. In late 1937 the Nationalist government was forced to retreat from its capital, Nanjing (Nanking), to Chongqing in western China.

sino-japanese war

A Chinese baby, a survivor of a Japanese bombing raid in Shanghai, 1937

Japanese troops were notorious for their brutal treatment of civilians and military prisoners. The Japanese occupation of Nanjing from December 1937, later referred to as the ‘Rape of Nanjing’, is the most infamous example of Japanese brutality. Estimates suggest that the Japanese massacred 300,000 people while capturing the city, many of them civilians. Historian Jonathan Fenby describes the Rape of Nanjing as a uniquely “urban atrocity” because of “the way the Japanese went about their killing, the wanton individual cruelty, the reduction of the city’s inhabitants to the status of sub-humans who could be murdered, tortured and raped at will.” Thousands were buried alive, machine gunned or used for bayonet practice. Females were also taken and forced into labour as “comfort women”: sex slaves for Japanese officers and soldiers. The Japanese also conducted human experimentation in secret bases in China. Unit 731 in the country’s northeast was the largest biological and chemical warfare testing facility. There prisoners were injected with diseases like anthrax, smallpox, cholera, dysentery and typhoid. Other experiments studied the effects of food deprivation and extreme cold; amputation without anaesthesia; and the effects of chemical weapons and flamethrowers. The Japanese also air-bombed cities like Ningbo and Changde with fleas carrying bubonic plague. Vast swathes of China were decimated by Japan’s ‘scorched earth’ policy of “kill all, loot all, destroy all.”

While Jiang Jieshi had some initial assistance from Soviet Russian leader Joseph Stalin, there was little support from foreign powers. In June 1938 Jiang ordered the dikes of the Yellow River dam to be blown, a desperate attempt to slow the advance of the Japanese invasion. While this ploy worked it also caused a devastating flood that killed between 500,000 to one million Chinese civilians and rendered as many as ten million homeless. This action and the resulting famine and human suffering contributed to rising hatred towards Jiang Jieshi and the Nationalist regime. Widespread corruption, rising inflation and high desertion rates, due to poor treatment of the mostly conscripted GMD soldiers, also created problems for the Guomindang.

sino-japanese war

US general Joseph Stilwell with Jiang Jieshi and Soong Meiling

Beyond 1938 the Sino-Japanese war reached a virtual stalemate. The sheer size of China, her lack of infrastructure and pockets of resistance all worked to slow the Japanese advance. By 1940 the Japanese controlled the entire north-eastern coast and areas up to 400 miles inland. They installed a puppet government in Nanjing under Wang Jingwei, a former Guomindang leader and rival to Jiang Jieshi. Foreign assistance did not come until after the Japanese bombing of Pearl Harbour in December 1941. As the United States was drawn into World War II, China became an important theatre of the war in the Asia-Pacific. In 1942 US general Joseph Stillwell was sent to China to assist with training, reorganisation and equipment. Jiang’s authoritarianism, however, prevented any chance of the two collaborating successfully. Jiang’s wife Soong Meiling, dubbed “Madame Chiang” by the Western press, proved a more skilled diplomat than her husband and was instrumental in securing some foreign assistance.

“The Nationalist government, which bore the major brunt of the fighting, was so depleted physically and spiritually that it was manifestly incapable of coping with the new challenges of the postwar era.”
Immanuel Hsu, historian

During the Sino-Japanese War the CCP continued to consolidate its base in Yanan, while the Red Army – later reorganised into the Eight Route Army and the New Fourth Army – defended the inland areas of the northwest. The Japanese had no desire to occupy rural areas in the interior, however, which gave rise to a false perception that the communists were better defenders. Many favourable reports from foreign visitors also came out of the Yanan Soviet during the war period, such as praise from the American Dixie Mission of 1944 and from President Roosevelt’s special emissary, Patrick Hurley. Zhou Enlai was also well respected among diplomats and foreign journalists. These events and factors were exploited by CCP propaganda, which boosted support for the party and allowed it to present as a legitimate alternative government to the Guomindang. By 1942 CCP membership had grown to 800,000, a twentyfold growth from the start of the war five years earlier. Scholars like David Goodman suggest that CCP’s tactics during this period were an essential element of the party’s eventual rise to power.

The Second Sino-Japanese War came to an end in August 1945, following the detonation of nuclear weapons over Hiroshima and Nagasaki. Russian troops invaded from the north and suppressed Japanese forces in Manchuria, while Japanese forces in China were ordered to surrender to Jiang Jieshi and the Guomindang. In assessing the impact of the war, historian Jonathan Fenby describes it as “an extended body blow for a regime already shot through with weaknesses. The length, scale and nature of the conflict had debilitated China and the Nationalists.” China emerged from the war politically unsettled, economically exhausted and having endured extreme amounts of human suffering. With the CCP growing in size, popularity and prestige, and the Guomindang government under threat, the Chinese stage was now cleared for civil war.


1. The Second Sino-Japanese War had its roots in decades of tension between the two nations. In contrast to the modernised and highly militarised Japanese, the Qing was militarily inept.
2. Already with a foothold in northern China and superior military technologies, the Japanese rapidly occupied the east coast of China in 1938 and 1939.
3. The Japanese used inhumane and sadistic methods during their occupation of China, typified by events like the Nanjing massacre and their use of human experimentation.
4. Jiang Jieshi was widely criticised for his wartime leadership, for placing more importance on the struggle against the communists than the Japanese. He also led a corrupt government plagued by economic issues and failed to work effectively with China’s foreign allies.
5. The war left the Nationalist government in a vulnerable position while the CCP consolidated and expanded their support, placing them in a more favourable position as China moved towards civil war.

© Alpha History 2014. Content on this page may not be republished or distributed without permission. For more information please refer to our Terms of Use.
This page was written by Rebecca Cairns. To reference this page, use the following citation:
Rebecca Cairns, “The Second Sino-Japanese War”, Alpha History, accessed [today’s date],
This website uses pinyin romanisations of Chinese words and names. For more information refer to this page.