How did the Xi’an Incident lead to cooperation between the Nationalists and the Chinese Communist Party?

The Xi’an Incident (December 12–25, 1936) served as the catalyst for the second United Front between the Nationalists and the Chinese Communist Party by forcing a shift in military priorities regarding the Japanese invasion of China.1

General Zhang Xueliang and Yang Hucheng seized Chiang Kai-shek at Xi’an to protest his policy of prioritizing the suppression of communists over resisting Japanese aggression. The rebels demanded an immediate end to the civil war and the formation of a national united front to defend the country.1

The Chinese communists, represented by Zhou Enlai, participated in the subsequent negotiations to support these demands. Following his oral agreement to these proposals, Chiang was released on December 25, 1936. This resolution effectively halted Nationalist military pressure on the communists, allowing them to rebuild their forces while both parties formally aligned to oppose the Japanese occupation.1