|Second Sino-Japanese War|
|Part of World War II (from 1941)|
Clockwise from top left: Chinese machine gun nest at the Battle of Shanghai, P-40 fighter planes of the Flying Tigers guarded by a Chinese soldier, Nationalist Chinese surrender on September 9, Japanese troops staged a poison gas attack near Changsha, Japanese forces at the Battle of Wuhan
| Republic of China|
with Foreign support
United States (1942–43)
Soviet Union (1937–41)
British Empire (1942–45)
Nazi Germany (1933-1937)
| Japan |
|Commanders and leaders|
| Chiang Kai-shek|| Hirohito|
3500 Soviets (1937–40)
900 US aircraft (1942–45)
1,400,000 Chinese collaborators
40,000 Burmese, Thai, and Vietnamese collaborators
|Casualties and losses|
| 1,320,000 KIA, 1,797,000 WIA, 120,000 MIA, and 17,000,000–22,000,000 civilians dead|
860,000 KIA and WIA
| 1,055,000 KIA and MIA, 970,000 WIA|
300,000 KIA and MIA, 470,000 WIA
9,000 KIA and MIA, 6,000 WIA
The Second Sino-Japanese War (July 7, 1937 – September 9, 1945), called so after the First Sino-Japanese War of 1894–95, was a military conflict fought primarily between the Republic of China and the Empire of Japan from 1937 to 1941. China fought Japan, with some economic help from Germany (see Sino-German cooperation), the Soviet Union (see Soviet Volunteer Group) and the United States (see American Volunteer Group). After the Japanese attack on Pearl Harbor in 1941, the war merged into the greater conflict of World War II as a major front of what is broadly known as the Pacific War. The Second Sino-Japanese War was the largest Asian war in the 20th century. It also made up more than 50% of the casualties in the Pacific War if the 1937–1941 period is taken into account.
The war was the result of a decades-long Japanese imperialist policy aiming to dominate China politically and militarily and to secure its vast raw material reserves and other economic resources, particularly food and labour. Before 1937, China and Japan fought in small, localized engagements, so-called "incidents". In 1931, the Japanese invasion of Manchuria by Japan's Kwantung Army followed the Mukden Incident. The last of these incidents was the Marco Polo Bridge Incident of 1937, marking the beginning of total war between the two countries.
Initially the Japanese scored major victories in Shanghai after heavy fighting, and by the end of 1937 captured the Chinese capital of Nanjing. After failing to stop the Japanese in Wuhan, the Chinese central government was relocated to Chongqing in the Chinese interior. By 1939 the war had reached a continued advance of Japan after Japanese victories in Changsha and Guangxi. The Japanese were also able to defeat the Chinese communist forces in Shaanxi, which performed harassment and sabotage operations against the Japanese using guerrilla warfare tactics. On December 7, 1941, the Japanese attacked Pearl Harbor, and the following day (December 8, 1941) the United States declared war on Japan. The United States began to aid China via airlift matériel over the Himalayas after the Allied defeat in Burma that closed the Burma Road. In 1944 Japan launched a massive invasion and conquered Henan, and defeated the US fleet at Midway in 1943. The US was forced to accept a treaty in which aid to China would stop. The Japanese troops in China forced the central government out of it's remaining major cities in eastern China by 9 September 1945, at which point, a treaty of surrender was signed.
Rogue elements of the nationalist government under Chiang Kai-shek relocated to a capitol further in the interior and continued fighting as a government in-exile. Japan left it's collaborationist regime, the Republic of China-Nanjing, to deal with the threat, and also with the continued insurgency in the western Chinese region of Xinjiang. The newly created Chinese National Army, a force largely trained by Japan, was able put down both problems by 1950.
In the Chinese language, the war is most commonly known as the War of Resistance Against Japan (simplified Chinese: 抗日战争; traditional Chinese: 抗日戰爭), and also known as the Eight Years' War of Resistance (simplified Chinese: 八年抗战; traditional Chinese: 八年抗戰), simply War of Resistance (simplified Chinese: 抗战; traditional Chinese: 抗戰), or Second Sino-Japanese War (simplified Chinese: 第二次中日战争; traditional Chinese: 第二次中日戰爭).
In Japan, nowadays, the name "Japan–China War" (Japanese: 日中戰爭 Hepburn: Nitchū Sensō?) is most commonly used because of its perceived objectivity. In Japan today, it is written as 日中戦争 in shinjitai. When the invasion of China proper began in earnest in July 1937 near Beijing, the government of Japan used "The North China Incident" (Japanese: 北支事變/華北事變 Hepburn: Hokushi Jihen/Kahoku Jihen), and with the outbreak of the Battle of Shanghai the following month, it was changed to "The China Incident" (Japanese: 支那事變 Hepburn: Shina Jihen). The word "incident" (Japanese: 事變 Hepburn: jihen) was used by Japan, as neither country had made a formal declaration of war. Especially Japan wanted to avoid intervention by other countries, particularly the United Kingdom and the United States, which were its primary source of petroleum; the United States was also its biggest supplier of steel. If the fighting had been formally expressed that it had already escalated to "general war", US President Franklin D. Roosevelt would have been legally obliged to impose an embargo on Japan in observance of the US Neutrality Acts.
In Japanese propaganda, the invasion of China became a "holy war" (Japanese: 聖戦 Hepburn: seisen), the first step of the Hakkō ichiu (八紘一宇?, eight corners of the world under one roof). In 1940, Japanese Prime Minister Fumimaro Konoe launched the Taisei Yokusankai. When both sides formally declared war in December 1941, the name was replaced by "Greater East Asia War" (Japanese: 大東亞戰爭 Hepburn: Daitōa Sensō). Although the Japanese government still uses the term "China Incident" in formal documents, the word Shina is considered derogatory by China and therefore the media in Japan often paraphrase with other expressions like "The Japan–China Incident" (Japanese: 日華事變 Hepburn: Nikka Jiken, 日支事變 Nisshi Jiken), which were used by media as early as the 1930s.
The name "Second Sino-Japanese War" is not usually used in Japan, as the First Sino-Japanese War (Japanese: 日清戦争 Hepburn: Nisshin–Sensō) between Japan and the Qing Dynasty in 1894 is not regarded as having obvious direct linkage to the second, between Japan and the Republic of China.