Zhuge Liang during the Liu Chan period can be said to have painstakingly supported the Shu Han Dynasty until his death in Wuzhangyuan. And Sima Yi, who was Zhuge Liang's "confidant", did not send troops to cut down Shu after Zhuge Liang's death, what was the reason?
First of all, from the perspective of the shu state
First, Zhuge Liang's death did not shake the foundation of the Shu state. Although the Wu-Shu alliance was briefly broken up during Liu Bei's conquest of Wu, it was soon reconciled. If the State of Wei rushed to cut down Shu, it would inevitably need to fight on two fronts, and it would be impossible to eat the strength of the troops and the people.
Second, the Shu general Jiang Wei provoked the Shu state liang, and the Shu state's military officials were very sincere to the hou lord Liu Chan, and even if the Shu army was victorious in the face of the same enemy, it would be the end of killing a thousand enemies and losing eight hundred.
Third, the State of Shu had taken full advantage of the geographical advantages, the State of Shu had a natural barrier, easy to defend and difficult to attack, sima Yi did not dare to use force easily even if he had a talent, after all, Sima Yi won in his life on a "stable" word.
Second, from the perspective of the Wei state
First, Cao Rui was not at ease with Sima Yi, after all, Sima Yi was too talented, Sima Yi was a double-edged sword, and if he was not careful, he would hurt himself, and even Cao Cao and Cao Pi had said that they should always guard against Sima Yi.
Second, Sima Yi is well aware of the principle of "flying birds are exhausted, good bows are hidden, cunning rabbits die, and lackeys are cooked", and once Zhuge Liang dies, Sima Yi will have no use value. Therefore, in order to protect himself, Sima Yi also had to restrain his strength.
Third, Cao Rui's life was short, and he died not long after, and entrusted it to Sima Yi, because the young lord was young, the government of the State of Wei fell into chaos, the struggle between Sima Yi and Cao Shuang became increasingly fierce, and the State of Wei, which intensified infighting, made Sima Yi no longer have time to distract himself to attack the State of Shu. Soon after, Sima Yi also died of illness, and Sima Yi could no longer cut shu.