Xi'an Incident
In 1936, Zhou Enlai and Zhang Xueliang grew closer, with Zhang even suggesting that he join the CCP. However, this was turned down by the Comintern in the USSR. Later on, Zhou persuaded Zhang and Yang Hucheng, another warlord, to instigate the Xi'an Incident. Chiang was placed under house arrest and forced to stop his attacks on the Red Army, instead focusing on the Japanese threat.