Known in China as the War of Resistance to Japan, the beginning of the Second Sino-Japanese War can be seen as the start of the Second World War. It was fought between the Empire of Japan and joint nationalist and communist forces of China.
But when did the war start? And what should it be remembered for?
1. According to most historians the Second Sino-Japanese War began in 1937 at the Marco Polo Bridge
On 7 July 1937, rifle fire was exchanged between startled Chinese troops stationed 30 miles from Beijing at the Marco Polo Bridge and a Japanese military training exercise. The exercise had not been disclosed as was customary.
After the skirmish, the Japanese declared themselves to be one soldier down and demanded to search the Chinese town of Wanping. They were refused and instead attempted to force their way in. Both countries sent support troops to the area.
Early in the morning of 8 July, fighting broke out at the Marco Polo bridge. Although the Japanese were initially driven back and a verbal agreement was reached, tensions did not again fall to the pre-incident level until after World War Two.
This incident is commonly perceived to have been the result of a conspiracy by the Japanese to continue their policy of expansion.
2. Japanese expansionism began far earlier
The First Sino-Japanese War took place between 1894 and 1895. It resulted in the ceding of Taiwan and the Liaodong peninsula from China, and the recognition of Korean independence. Then, when the Chinese Qing dynasty collapsed in 1912, the Japanese government and military took advantage of the division within the new Republic of China to forge alliances with local warlords.
Three years later, during the First World War, Japan issued the Twenty-One Demands for concessions within Chinese territory. Thirteen of these demands were accepted after an ultimatum, but the event greatly increased anti-Japanese feeling in China, and confirmed Japanese expansionist intentions to the Allied powers.
3. Full military invasion began in 1931 in Manchuria
One of the warlords supported by the Japanese was Zhang Zuolin of Manchuria, a region in the north-east of China. Japanese influence in the area was also bolstered by their ownership of the South Manchurian Railway.
During the night of 18 September 1931, part of that railway was blown up, beginning the Mukden Incident. The bombing was attributed to Chinese sabotage, and the Japanese army staged a full military invasion of Manchuria.
The Republic of China appealed to the League of Nations and a commission was set up. The resulting Lytton Report, published in 1932, concluded that the Imperial Japanese operations were not self defence. In February 1933, a motion was raised in the League of Nations condemning the Japanese Army as the aggressor.
By the time the Lytton Commission had even published their report, however, the Japanese army had occupied the entirety of Manchuria, and created a puppet state – Manchukuo – with the last Qing emperor, Puyi, as its head of state.
When the Lytton Report was presented, the Japanese delegation withdrew from the League of Nations. The new state was eventually recognised by Japan, Italy, Spain and Nazi Germany.
4. It made up over half of the casualties in the Pacific War
Taking the period from 1937 into account, estimates for the number of Chinese civilians and military personnel killed reach up to 15 million.
Almost 500,000 of the 2 million Japanese deaths during the Second World War were lost in China.
5. The Chinese Civil War was suspended
In 1927, an alliance between the Chinese Nationalists, the Kuomintang, and the Chinese Communist Party had collapsed when the former sought to reunify China with their Northern Expedition. The two had been in conflict ever since.
In December 1936, however, the Nationalist leader Chinag Kai-shek was kidnapped by the Communists. They persuaded him to agree to a truce and to unite with them against Japanese aggression. In reality, the cooperation of the two parties was minimal, and the Communists took advantage of the weakening of the Kuomintang to gain territorial advantages for the future.
The Communists also recruited large numbers of dispossessed Chinese villagers during and after the war, using their perception as integral to the fight against Japan, which they gained as guerilla fighters. The Civil War was reignited after the Second World War over issues of territory in places where there had only been Communist fighters present on the Japanese surrender.
6. The Nazis funded both sides
From the late 1920s until 1937, Chinese modernisation was supported by Germany, first with the Weimar Republic and then with the Nazi Government. In return, Germany received raw materials.
Although the Nazis sided with Japan when war broke out, they had already been instrumental in improvements to the Chinese military. The Hanyang Arsenal, for example, produced machine guns based on German blueprints.
The German-Japanese relationship picked up in 1936 with the signing of the Anti-Comintern Pact, and later with the Tripartite Pact of 1940, by which they would ‘assist one another with all political, economic and military means.’
7. The Japanese policy has been remembered as the ‘Three Alls’
Kill all. Burn all. Loot all. Within the first six months of fighting, Japan had control of Beijing, Tianjin and Shanghai. Already there were rumours of atrocities committed by the invading force. Then, in December 1937, the Japanese forces focused on the capital, Nanjing. What followed were countless acts of violence against civilians; looting, murder and rape.
Around 300,000 were murdered in Nanjing. Tens of thousands of women were raped and at least one third of the city was left in ruins.
The Nanjing Safety Zone, a demilitarised area of the city, was not targeted with bombs as other areas were. The Japanese military did, however, encroach into the area claiming that there were guerillas there.
8. The Japanese atrocities also included biological and chemical warfare
Unit 731 was set up in 1936 in Manchukuo. Eventually comprising of 3,000 personnel, 150 buildings and a 600 prisoner capacity, the unit was a research centre.
To develop biological weapons, doctors and scientists deliberately infected Chinese prisoners with plague, anthrax and cholera. Plague bombs were then tested in northern and eastern China. Prisoners were vivisected – cut open – alive and sometimes without sedation for study and practice. They were also subjected to poison gas experiments.
Other projects studied the impact of food deprivation and the best treatment for frostbite – for which prisoners were taken out, wet and unclothed, until frostbite set in.
After the war, some Japanese scientists and leaders were granted immunity from War Crimes trials by the United States in return for the results of their research. Testimonies have suggested that human experimentation was not exclusive to Unit 731.
9. The Chinese defence strategy caused a disastrous flood
In a move to defend Wuhan against the advancing Japanese troops, the Chinese Nationalist armies under Chiang Kai-shek breached the dams of the Yellow River in Henan province in June 1938.
The flooding of the Yellow River is said to have led to four million people losing their homes, the destruction of vast amounts of crops and livestock, and 800,000 Chinese deaths. The flooding continued for nine years, but delayed the Japanese capture of Wuhan by just 5 months.
10. Stalemate was only broken by Japan’s attack on the United States
In 1939, the war between Japan and the joint Nationalist and Communist forces of China was at a stalemate. Only when the Japanese bombed Pearl Harbour in 1941, in light of American sanctions and interference, did the war pick up again when China declared war against Japan, Germany and Italy.