After the Xi'an Incident, the thirty-six-year-old Zhang Xueliang was put under house arrest by Chiang Kai-shek, and since then he has lost his freedom and has not seen the light of day, and the once spirited young marshal has been trapped by the father and son of the Chiang family for fifty-four years, and everyone thinks that Zhang Xueliang can restore his freedom after Chiang Kai-shek's death, but Chiang Ching-kuo did not release Zhang Xueliang, if it were not for his tough and super long standby, then I am afraid that there would be no chance to regain his freedom.

After Chiang Ching-kuo's death, Zhang Xueliang was finally released, he left Taiwan Province without much stay, settled in the United States in his later years, and was reluctant to look back on the past, although Zhang Xueliang had many controversies in modern history, but the Xi'an Incident launched by him and General Yang Hucheng made a major contribution to China's resistance against Japan, and therefore was regarded by Chiang Kai-shek as a thorn in the eye, the two once fell in love with each other, and after this incident Chiang Kai-shek hated him to the bone.
Originally, Chiang Kai-shek wanted to execute Zhang Xueliang, but he was jealous of the power of the Northeast Army, and all parties were interceding for Zhang Xueliang, so in the end the young marshal saved his life, but he was unwilling to let Zhang Xueliang go for the rest of his life, preferring to bear a large amount of house arrest every year, rather than let Zhang Xueliang restore his freedom, and repeatedly warned his son Chiang Ching-kuo before his death, and revealed the real reason for his house arrest of Zhang Xueliang.
It turned out that Chiang Kai-shek no longer had any trust in Zhang Xueliang, and his original words to Chiang Ching-kuo were: Don't let go of the tiger. Because Zhang Xueliang's old subordinates are still quite powerful, Chiang Kai-shek is worried that Zhang Xueliang will continue to do something that threatens him once he regains his freedom, so he repeatedly warned his son that Zhang Xueliang must not be released.