On December 12, 1936, Zhang Xueliang and Yang Hucheng launched the "Xi'an Incident" that shocked China and foreign countries, the purpose was to make the general stop opposing communism and unanimously resist Japan, which was a famous military advice in history, and after the fact, Yang Hucheng was wiped out, but Zhang Xueliang has been imprisoned, so why did Chiang Kai-shek not kill Zhang Xueliang that year?
The first point of view: During the Central Plains War, Zhang Xueliang openly supported Chiang Kai-shek and let Chiang Kai-shek turn defeat into victory, that is to say, Zhang Xueliang was kind to Chiang Kai-shek, and this kindness was very large, so Chiang Kai-shek did not kill Zhang Xueliang.
The second view: Chiang Kai-shek was able to nominally unify China to a large extent thanks to Zhang Xueliang's "Northeast Yizhi", and it is expected that if Zhang Xueliang did not "change the Northeast Yizhi", then Chiang Kai-shek could reunify China? The answer is no, because at that time, the various factions were not harmonious, and the unification was only nominal, so Zhang Xueliang helped Chiang Kai-shek again, so Chiang Kai-shek hindered these virtues, so he never killed Zhang Xueliang, but only put him under house arrest.
The third point of view: We all know that Zhang Xueliang and Chiang Kai-shek are brothers, brotherhood is true affection, Chiang Kai-shek has true feelings for Zhang Xueliang, zhang Xueliang was very good in the early stage, of course, there are also elements of use, because Chiang Kai-shek is very good at winning people's hearts and earning political capital, if you kill Zhang Xueliang because of the Xi'an incident, it is inevitable that you will not be able to live morally, because it is difficult to convince the public, if you really kill, many people will feel that Chiang Kai-shek this person has no human touch, when he helps you, he is a brother, and when he demolishes you, he is an enemy. This is somewhat unreasonable, so Chiang Kai-shek did not kill Zhang Xueliang.
The fourth point of view: Zhang Xueliang has an army in his hands, hundreds of thousands of northeast troops are not vegetarians, if Chiang Kai-shek dares to move Zhang Xueliang, then there will be a rebellion, it is expected that hundreds of thousands of northeast troops will make trouble together, the consequences will be unimaginable, so Chiang Kai-shek does not dare to kill Zhang Xueliang because of this factor, because Zhang Xueliang is still useful, because his presence can appease the northeast, so he only imprisons Zhang Xueliang.
Fifth view: Zhang Xueliang's influence in those years was huge, whether at home or abroad, if Zhang Xueliang was killed, it was bound to cause pressure on public opinion, and even affect the relations of the Nationalist government to Japan, the Soviet Union, and the United States, so zhang Xueliang could only be left behind, not Zhang Xueliang.
Sixth point of view: Zhang Xueliang and Song Meiling have a very good relationship, Song Meiling has been protecting Zhang Xueliang's personal safety, and even once said to Chiang Kai-shek: "If you dare to move that little thing, I will tell you about your ugly things", including Zhang Xueliang's recollection in his later years: "I am not dead, it is completely Mrs. Chiang's protection", which shows that Song Meiling protected Zhang Xueliang, so Chiang Kai-shek obstructed Song Meiling's face and never killed Zhang Xueliang.
In the end, Zhang Xueliang was imprisoned for a full 54 years, and was not released until Chiang Ching-kuo's death, in fact, Zhang Xueliang could have come out earlier because of Chiang Kai-shek's dying words, "This cage is a tiger, you can't let go", so Chiang Ching-kuo did not release Zhang Xueliang until after Chiang Ching-kuo's death.
History is such a reality, Chiang Kai-shek may hate Zhang Xueliang to the bone, so he still does not want to let him go until he dies.