During the Northern Expedition to reunify a fragmented China, Kuomintang policy was one of "allying with Russia and tolerating the communists" under the First United Front between the KMT and Communist Party of China. However, after the anti-communist faction of the KMT led by Chiang Kai-shek organized a massacre of communists and leftists in April 1927, the nationalist government in Wuhan, led by Wang Jingwei, denounced Chiang, who established his own government in Nanjing, marking the start of the Nanjing–Wuhan split. The Wuhan government initially maintained the alliance with the CPC but later, tension escalated between them. Warlords such as Feng Yuxiang, who commanded large military forces, also called for severing of ties with the Communist Party. KMT leftist–CPC relations remained close after the "Shanghai massacre" purge of communists by Chiang Kai-shek on 12 April, and joint KMT–CPC conferences continued to be held frequently. Workers and farmers' movements continued to grow, but some KMT generals and soldiers, especially those from landowning or merchant families, were disturbed by an increase in class warfare killings. :zh:许克祥|Xu Kexiang, the KMT regimental commander of the 33rd regiment, 35th army launched an operation to disarm the communists on 21 May, and before long, Xia Douyin, the commander of the 14th Independent Division, also led an anti-communist mutiny. Although the Wuhan government had ordered their suppression, under the protection of warlord He Jian and other officials, they succeeded in defecting to the Nanjing government, which led to Wuhan losing control of parts of Hubei and most of Hunan. On 29 June, Wuhan garrison commander Li Pinxian and He Jian openly declared their support for the anti-communist cause, and dispersed the Hankou strikers and their militant forces. As disruption and discord continued at Wuhan, the Communist International issued a series of orders known as the "May Instructions" on 1 June, which Wang thought would destroy the KMT. Under increasing pressure, Wang decided to break with the communists and the Soviet Union.
On 15 July, Wang Jingwei held a meeting within KMT, during which he formally publicised the content of the "May Instructions" and condemned CPC's decisions, though he maintained the position that non-violent methods should be used to remove the communists from Wuhan. This proposal met with approval from most members; the only one who protested and walked out was Soong Ching-ling's representative Eugene Chen. In the end, the meeting passed the "Policy of Uniting the Party", a statement that was directed against CPC's declaration, requesting that all the communists within the KMT and the army immediately declare their withdrawal from the CPC or face immediate suspension. Additionally, the Wuhan government sent envoys to Moscow to discuss how to bilaterally guarantee the freedom and safety of the communists who were about to withdraw. After Wang was made aware of the CPC declaration of 13 July, on the following day, in the name of the political committee presidium, he accused the communist party of having "ruined the revolution", and suspended all the communists from the Wuhan government. Chief Soviet advisor to the Wuhan government Mikhail Borodin left Wuhan secretly sometime between 13–16 July. Upon hearing of his having left, General He Jian opened fire on Borodin's former headquarters, and martial law was declared. KMT forces loyal to Chiang Kai-shek gradually began to take over the city, and Jian's troops raided leftist strongholds and arrested or killed those who had not fled. Soviet military advisorVasily Blyukher escaped an assassination attempt as he left the city for Shanghai, where he bid farewell to Chiang, who allowed him to escape to Russia. By the 18th, Wuhan was awash in anti-communist, anti-Soviet, and anti-Borodin propaganda posters. Although the Wuhan government was purging communists, this did not immediately mean that their confrontation with Chiang Kai-shek had ended, and they persisted in regarding him as "the only enemy to our country and party". In response to the purge, CPC forces launched the Nanchang uprising against the KMT Wuhan government on 1 August, beginning the Chinese Civil War, and on the 19th, the Wuhan government reconciled with the Nanjing government.
