Zhang Xueliang was an idiot and a sinner in KMT and Chinese history. at that time, Zhang had over 150K troops encircling the Communist's LAST stronghold Yan’an 30K troops. Chiang Kai Shek had already assembled over 300K central government troops ready to join Zhang for a final annihilation of the Communists. the KMT had superior weapons with 15 to 1 numerical advantage to totally destroy the CCP this time. Chiang went to Xi’an to raise the morale of Zhang’s troops despite his aides advising him not to, there were prior intelligence warnings that Zhang was getting too close with the CCP. the Communist brainwashed Zhang staged a mutiny and held Chiang prisoner, throwing the country into chaos. when Chiang was released and returned to Nanjing, Chen Lifu tried to convince Chiang that he should continue the final battle against the CCP. Chiang said no. China’s political climate had changed dramatically in just 2 weeks from the people hoping to see a conclusion to the civil war to looking forward to the KMT-CCP alliance against Japan. the CCP’s status totally changed from an illegal outlawed party on the verge of annihilation to a significant coalition party. the KMT’s final victory against the CCP was so close, and it damn flew away just like that.