所謂第二次「國共合作」係指中共紅軍接受政府改編，納入國軍體系，國共雙方「攜手」抵抗日本侵略者。「西安事變」的和平解決，預告著國共兩黨將進入一個嶄新的關係，中共原本所設想建立的西北大聯合政府，在少了東北軍這個主要的支柱後，「三位一體」可謂名存實亡。相反的，中共要面對的是比東北軍更難纏的中央軍，而當前要思考的是如何從蔣介石手中獲取發展的最大利益。在這場代理人的談判中，張冲忠實地執行蔣介石對共黨的策略，適時的調解談判過程中雙方緊張的關係。

The so-called the second KMT-CCP cooperation means the Chinese Communist Party accepted Red Army enlisted and restructured by kuomintang government Military System. They cooperated to against Japanese invaders. It represents that a new turn in the relations between the two parties after Xi'an Incident was over in peace. Lacking of main support, CCP can't found Northwest Coalition Government. That is why “three-in-one” become only a shadow. In contrast to Northeastern Army, CCP was difficult to deal with the Central Army and must think deeply how to get the most benefit from Chiang Kai-shek. When Zhang Chong was on behalf of Chiang Kai-shek to attend a negotiation meeting with CCP, he loyally executed Chiang Kai-she's strategy for the CCP and helped defuse tensions and maintain peace in both.