Second Sino-Japanese War

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Lore & Background

The Second Sino-Japanese War was the largest conflict in Asia during the 20th century, spanning from 1937 to 1945, with roots in localized fighting in Manchuria beginning in 1931. Its appearance was defined by a full-scale Japanese invasion of China following the Marco Polo Bridge incident near Beijing, which escalated into a brutal, protracted struggle across vast territories. The war’s range extended from the northeastern puppet state of Manchukuo, established after the 1931 Mukden incident, through major urban centers like Shanghai and Nanjing, deep into the Chinese interior to Wuhan and the wartime capital of Chongqing, and eventually into Burma, where Chinese forces fought alongside British Empire troops. The habitat of the conflict included dense cities, rural plains, and mountainous regions, with Japanese forces occupying coastal and central areas while Chinese Nationalist and Communist forces retreated to the interior and waged guerrilla warfare from bases like Shaanxi. Defining characteristics include the initial stalemate after 1939, marked by Chinese victories at Changsha and Japanese overextension; the use of scorched earth policies by Japan that killed millions of civilians; and Japan’s deployment of biological warfare and chemical weapons, including lethal blister agents, causing at least 200,000 deaths. The war also saw the formation of a United Front between Chiang Kai-shek’s Nationalists and Mao Zedong’s Communists, despite their ongoing civil war, and massive Allied aid via the Burma Road and airlifts over the Himalayas after 1941. The conflict ended with Japan’s surrender in September 1945, following atomic bombings and a Soviet invasion, resulting in around 20 million deaths, mostly Chinese civilians.

Reader's Guide

The war is considered to have begun on 7 July 1937 after the Marco Polo Bridge incident near Beijing, which escalated into full-scale Japanese invasion of the rest of China. Following the protracted Battle of Shanghai, the Japanese captured the capital of Nanjing in 1937 and perpetrated the Nanjing Massacre. After failing to stop the Japanese capture of Wuhan in 1938, China's de facto capital at the time, the Nationalist government relocated to Chongqing in the Chinese interior. By 1939, after Chinese victories at Changsha and with Japan's lines of communication stretched deep into the interior, the war reached a stalemate. The Japanese were unable to defeat CCP forces in Shaanxi, who waged a campaign of sabotage and guerrilla warfare. In November 1939, Nationalist forces launched a large scale winter offensive, and in August 1940, CCP forces launched the Hundred Regiments Offensive in central China. In retaliation, Japanese forces implemented massive scorched earth policies in North and Central China, killing millions of civilians. In December 1941, Japan launched a surprise attack on Pearl Harbor and declared war on the United States and the United Kingdom. The US increased its aid to China under the Lend-Lease Act, becoming its main financial and military supporter. The British Empire supported the Chinese forces against Japan by sending supplies through the Burma Road. In 1944, Japan launched Operation Ichi-Go, the invasion of Henan and Changsha. In 1945, China launched large counteroffensives in South China, repulsed a failed Japanese invasion of West Hunan, and recaptured Japanese occupied regions of Guangxi. Japan formally surrendered on 2 September 1945, following the atomic bombings of Hiroshima and Nagasaki, Soviet declaration of war and subsequent invasion of Manchuria, Inner Mongolia and Korea.

Did You Know?

• On 18 September 1931, the Japanese staged the Mukden incident, a false flag event fabricated to justify their invasion of Manchuria and establishment of the puppet state of Manchukuo.
• Japan carried out the largest attacks in the history of biological warfare, causing at least 200,000 deaths, and used chemical weapons including lethal blister agents.
• The Chinese Civil War resumed in 1946, ending with a communist victory and the Proclamation of the People's Republic of China in 1949, while the government of the Republic of China relocated to Taiwan.
• In Japanese propaganda, the invasion of China became a holy war (聖戦, seisen), the first step of the 'eight corners of the world under one roof' slogan (八紘一宇, Hakkō ichiu).
• China was recognized as one of the Big Four Allied powers in World War II and one of the 'Four Policemen', which formed the foundation of the United Nations.