July 15 Incident

During the Northern Expedition (1926–1928) to reunify a fragmented China, Kuomintang policy was one of "allying with Russia and tolerating the communists" (Chinese: 联俄容共) under the First United Front between the KMT and CCP.

KMT leftist–CCP relations remained close after the "Shanghai massacre" purge of communists by Chiang Kai-shek on 12 April, and joint KMT–CCP conferences continued to be held frequently.

[1] 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.

As disruption and discord continued at Wuhan, the Communist International (Comintern) issued a series of orders known as the "May Instructions" on 1 June, which Wang thought would destroy the KMT.

On 15 July, Wang Jingwei held a meeting within KMT, during which he formally publicised the content of the "May Instructions" and condemned CCP's decisions, though he maintained the position that non-violent methods should be used to remove the communists from Wuhan.