In 1936, an opportunity arose to form the [[Second United Front]] to resist the Japanese invader. At that time, the southern part of Shanxi Province (itself in North China) was under the control of Zhang Xueliang, a military strongman who was part of the KMT. His father had been a warlord in Northern China who was assassinated by the Japanese in 1928. This made Zhang inclined to take a strong stand against Japanese aggression, and he perceived Chiang Kai-shek's as being unwilling to push them out.<ref name=":033">{{Citation|author=Dr. Ken Hammond|year=2004|title=From Yao to Mao: 5000 years of Chinese history|chapter=Lecture 34: War and Revolution|publisher=The Teaching Company}}</ref>Chiang Kai-shek was placed under house arrest during a visit, and Zhang then sought out to invite CPC representatives, who sent Zhou Enlai. An agreement was then reached to form a united front to resist the Japanese invasion. Chiang Kai-shek was then released upon the conclusion of this accord and placed Zhang under house arrest in turn, in which he would remain until the end of the 1990s as he was taken to Taiwan when the KMT fled there.<ref name=":033" />
Start of the Second Sino-Japanese war
In 1931, Japan invaded China in the continuation of their imperialist ambitions in Asia. They first occupied Manchuria and created a puppet state there which they called [[Manchuko|Manchukuo]], with the last of the Manchu emperor, Puyi, named as its ruler. In July 1937, Japan then started a full scale invasion into the rest of China.<ref name=":033" />
The invasion of China was pursued relentlessly along two basic lines: part of the Japanese Imperial Army moved from Manchukuo down south, crossing the Great Wall and into Beijing down to Wuhan. The second front started at the city of Shanghai, which was at the time a very international city, home to Statesians, French and British citizens. In the Fall of 1937, the Japanese troops stationed there attacked the Chinese (western) side of Shanghai, and then followed a course west, up the Yangtze river.<ref name=":033" />
The Japanese plan was to let both groups meet at Wuhan, which they expected to happen fairly quickly in a blitzkrieg invasion. This did not work out however, as the resistance put up by the Chinese was much more intense than the Japanese had anticipated.<ref name=":033" />
Nonetheless, the nationalist government was forced to retreat from Nanjing to Wuhan, and eventually out of Wuhan to Chongqing. When the Japanese reached Nanjing, which was the KMT's capital, they committed the [[Rape of Nanjing]]: hundreds of thousands of people were killed and many women were raped.<ref name=":033" /> To this day, the Japanese government has not apologized for it and formally denied the massace even took place in 1990.<ref>{{Web citation|newspaper=Nanking Massacre: the untold story|title=Denials|date=2007|url=https://depts.washington.edu/triolive/quest/2007/TTQ07032/yuen/denials.html|archive-url=https://archive.ph/gH66B|archive-date=2024-04-15}}</ref>While this event was meant to terrorize the Chinese, it actually galvanized the resistance. After the first two years of the war, the front stabilized. The KMT had their main center of operations in Chongqing and another in Kunming. The Japanese did not occupy all of South China, and pockets of KMT forces continued to operate there long after the initial invasion.<ref name=":033" />
In the North, the CPC had their base area in Yan'an from which they pursued a vast campaign of guerilla warfare across all of North China. During the daytime, the Imperial Japanese Army could certainly extend their presence but at night, except for the areas along the main railway lines and large towns, much of the countryside was in the hands of communist guerillas, who carried out operations to harass and tie down lots of Japanese troops.<ref name=":033" />
This pattern persisted for several years, with Japan occupying much of China but unable to push their conquest further and achieve total control of their occupied territories. Their invasion of China, which was designed to help them solve their economic and population problems at home, proved to be a very counter-productive endeavour.<ref name=":033" />
End of the war and proclamation of the People's Republic
By 1944, it became clear that the defeat of Japan was inevitable despite their victories in 1941-42. In anticipation of the US and the Soviets invading the Japanese islands culminating in its surrender, Chiang Kai-shek and the KMT pursued a static strategy, without launching any major offensives and fighting mostly along defensive lines. Chiang Kai-shek had received a large amount of military aid from the US during the war, but he refused to use it, instead stockpiling it for the civil war against the CPC.<ref name=":033" />
As for the CPC, they saw the coming end of the war as setting the stage for a revolutionary confrontation between their movement and the nationalist government. The anti-Japanese resistance, which the CPC had spearheaded, had won the communists great support from the Chinese population, which helped to spread popular support for the Chinese Red Army and the CPC in general. Meanwhile, they were able to project an image of Chiang Kai-shek as corrupt and unpatriotic.<ref name=":033" />
When Japan surrendered in September of 1945, a period ensued in China where efforts were made to negotiate a coalition government for after the war. The US sent representatives to bring leaders from both factions together but, while that was going on, a lot of maneuvering was taking place on the ground. The Soviets had liberated Manchuria in 1945 shortly before Japan surrendered and in doing so passed some aid to the communist forces.<ref name=":033" />
Meanwhile, the USA was turning over lots of Japanese arms to the KMT. As such, although negotiations were taking place, both parties were strenghtening their military capabilities in preparation for a civil war. When the negotiations broke down by the end of 1946, full-scale fighting broke out between the CPC and KMT. The KMT drove the communists out of their base at Yan'an but this proved to be fairly meaningless, as the CPC had most of their support base in North China and Manchuria, which quickly joined them in the fight.<ref name=":033" />
In 1948, a battle took place at the Huai river, involving more than a million soldiers combined. The CPC emerged victorious from it and broke the KMT army. Political support for the KMT disintegrated due to their poor image, and Chiang Kai-shek began to withdraw his forces to the island of Taiwan. This was preceded first by an uprising of the indigenous Taiwanese population who refused the KMT occupation. There, the KMT committed a massacre of more than 20,000 Taiwanese in order to pacify the island. Martial law was imposed and stayed in effect for over 40 years.<ref name=":033" />
In 1949, the remaining nationalist forces in mainland China were completely broken down and the remains of the KMT fled to Taiwan entirely. In April, the communist forces entered Beijing after negotiating a bloodless surrender following a long siege. Over the summer of that year, as communist forces advanced across China, the leadership settled in Beijing and began to prepare establishing a new government. On October 1st, the People's Republic of China was proclaimed by Mao Zedong at Tiananmen.<ref name=":033" />
