On the question of whether to attack the Shu state, Sima Yi had some unspeakable secrets, but mainly he was acting and full of intrigue and trickery.
Let's dissect Sima Yi as a person, look at his life trajectory, and then talk about why he did not cut shu all his life.
Sima Yi's family can be said to be quite prominent, and his ancestor Cheng Boxiu's father was named Grand Sima during the zhou Xuanwang period because of his outstanding military achievements, and his descendants took Sima as their surname.
Sima Yi's twelfth ancestor Sima Yi followed Xiang Yu to destroy his relatives, was crowned the King of Yin, and the capital was Hanoi, which was established during the Han Dynasty, and his descendants lived here for generations.
During the Eastern Han Dynasty, Sima Yi's great-grandfather Sima Jun, great-grandfather Sima Liang, and grandfather Sima Juan were all high-ranking officials of the imperial court, at least officials of the Taishou level, and the Sima family became a famous family in Hanoi County.
Sima Yi's father Sima Fang had served as Jing Zhaoyin, he was honest and fair, knowledgeable, and a representative figure of the Sima clan in Hanoi, his eight sons were all young talents, and were called Sima Bada by the people of the time, of which the second eldest Sima Yi was famous very early, and was the most outstanding of Sima Fang's sons.
Sima Fang's initial contact with the Cao family began when he recommended Cao Cao as a filial piety and helped Cao Cao to serve in Luoyang, which led Cao Cao to start a career as an official eunuch and accumulated a lot of connections and prestige, which laid a solid foundation for his later career development.
However, after Cao Cao held Emperor Xian of Han hostage, Sima Fang, who was loyal to the Han Dynasty, lost his good feelings for him and refused to continue to serve in the imperial court, but only studied at home to provide for the elderly and educate his sons, in fact, for self-preservation.
Under the influence of Sima Fang, Sima Yi did not have a good feeling for Cao Cao, and Cao Cao summoned him several times to join the court as an official, but he refused on the grounds of illness, and later he annoyed Cao Cao and arrested him for persecution, which he had to do.
Why did Cao Cao have to recruit Sima Yi?
There were two reasons, one was because Cao Cao was recruiting talents at that time, and Sima Yi was able to excel and be able to do great responsibilities; second, Cao Cao was very eager to win over the Sima family for his own use, and he recruited Sima Yi with political purposes.
In any case, Sima Yi eventually came to Cao Cao's side, and performed quite well, following Cao Cao on expeditions to various places many times and coming up with many good strategies.
For example, when Guan Yu besieged Xiangfan, Sima Yi suggested that Cao Cao contact Sun Quan and let Sun Quan raid Jingzhou, which later worked, Guan Yu was captured and killed by Lü Meng, jingzhou was divided between Sun Cao's two families, and the situation in the three kingdoms was changed.
However, in the process of getting along with Sima Yi, Cao Cao found that Sima Yi had a wolf and was not a person who was willing to be a subordinate, so Cao Cao was very jealous of him.
However, Sima Yi was more intelligent, and acted very low-key and obedient, which dispelled Cao Cao's concerns, and he actively established good relations with Cao Pi, and was protected by Cao Pi.
Later, Cao Cao asked Sima Yi to assist Cao Pi, and under his strategy, Cao Pi eventually became Cao Cao's heir.
After Cao Pi succeeded to the throne, he reused Sima Yi, but he did not fully trust Sima Yi, but only entrusted him with administrative affairs and did not let him get too involved in the army.
Therefore, during the seven years of Cao Pi's reign, the last thing Sima Yi did was to stay in the rear and provide logistical services for the army, and he also knew that Cao Pi was jealous of him, so he was very low-key, just doing his internal affairs well, and did not show any other thoughts.
After Cao Pi's death, the Wei Ming Emperor Cao Rui succeeded to the throne, and Sima Yi, Chen Qun, Cao Zhen, and Cao Xiu became ministers of Gu Ming.
Cao Rui was a very simple man, he was calm and resolute, wise and decisive, well versed in the way of checks and balances, he knew that the four ministers who took care of his orders were an obstacle to his grasp of great power, so he took the strategy of attacking the west from the east, transferring Sima Yi, Cao Zhen, and Cao Xiu to the border, letting them lead troops to fight, and only leaving Chen Qun, who had no real power, in the capital, so he had great power in his hands and held everyone dead in his hands.
It was in this context that Sima Yi came to the border of Wei shu and became the main general to resist Zhuge Liang's Northern Expedition, but he was also monitored by Cao Zhen and other members of the clan, or under the operation of Cao Rui, these people balanced each other.
For Sima Yi, although he became the commander of the army, his situation was quite unfortunate, he was completely caught in the palm of the hand by Emperor Cao Rui, and once he was suspected, there was a danger of family collapse, what to do?
Sima Yi finally thought of a good way, that is, Ming Xiu Dao secretly Chen Cang, ostensibly obeyed Cao Rui, and led his army to fight with Zhuge Liang, but in fact adopted a turtle shrinking strategy and did not actively attack, the advantage of this was that as long as Zhuge Liang's threat was still there, Cao Rui had to reuse him.
Especially after the deaths of Cao Zhen and Cao Xiu, Sima Yi's role was even more irreplaceable, and Cao Ruiming knew that he was not enterprising enough, but he was helpless, after all, he resisted Zhuge Liang's attack, the role was still very obvious, and others could not do it.
Taking advantage of several opportunities to engage Zhuge Liang, Sima Yi also did many other things, such as repelling dissidents in the army, cultivating his own forces, and finally firmly controlling the military power in his hands.
Of course, everything Sima Yi did was very hidden, such as the general Zhang Guo, who was loyal to Cao Wei, who was killed by Sima Yi through Zhuge Liang's hand, and the general Guo Huai was successfully subdued by Sima Yi, becoming his confidant general and one of the key figures in his continuous control of the army.
In Zhuge Liang's last Northern Expedition, Sima Yi exerted his policy of shrinking to the extreme, and the Wei Ming Emperor Cao Rui ordered him to attack several times, but he insisted on the strategy of "refusing to defend the wall and waiting for work", and confronted Zhuge Liang for more than half a year, Zhuge Liang repeatedly issued war books, and even sent women clothes to him to wear, in order to provoke him, he did not send troops.
However, what Sima Yi could not imagine was that Zhuge Liang later died of illness in Wuzhangyuan, which made him very panicked, because he knew that Cao Wei's threat would be lifted, and his good life would come to an end, and the difficulties he would face in the future would be more, what should he do?
Shortly after Zhuge Liang's death, Sima Yi wrote a letter to Cao Rui, saying that after Zhuge Liang's death, civil unrest broke out in the Shu Han army (Yang Yi killed Wei Yan), which was a good opportunity for the Xingbing army to cut down Shu, and he wanted to continue to control the army, but Cao Rui was not a fool, did not approve his request, and also made him a lieutenant for his merits and let him take up a post in Beijing.
According to Cao Rui's idea, since the threat from Shu Han was lifted, Sima Yi's role was gone, and he could be put in Beijing to monitor him.
However, what Cao Rui did not expect was that shortly after Sima Yi entered the capital, Gongsun Yuan, the Taishou of Liaodong, betrayed Cao Wei, established himself as the King of Yan, and colluded with Eastern Wu, which greatly angered him, so he ordered Yuqiu Jian to send troops to fight, but was defeated by Gongsun Yuan.
Cao Rui looked left and right, did not find out who had the ability to defeat Gongsun Yuan, and had no choice but to let Sima Yi out of the mountains and serve as the main general of the crusade against Gongsun Yuan.
In fact, at that time, Cao Wei's clan and Xiahou clan had begun to decline, the older generation of famous generals had died, there were not many young talents who could hold great responsibilities, Cao Shuang and Xiahou Xuan were very famous, but there were empty names; Xiahou Ba was not bad, but his relationship with Guo Huai was not harmonious, and he had been suppressed.
Therefore, Cao Rui was also very helpless to reuse Sima Yi, but his advantage was that he was young, he still had a lot of time to plan and operate, and the hope of cultivating his own people to replace Sima Yi was still great.
However, what everyone did not expect was that Cao Rui's private life was too chaotic (Guangcai's women) and he died young!
The thing is, shortly after Sima Yi pacified Liaodong, Cao Rui ordered him to return to the dynasty and go to Guanzhong to garrison, and just as he was halfway there, the news of Cao Rui's serious illness came and asked him to return to Beijing immediately.
After Sima Yi returned to Beijing, Cao Rui received him and made him a minister with Cao Shuang, assisting the eight-year-old Cao Fang, who died soon after.
Cao Rui continued to reuse Sima Yi, which was also unavoidable, because Sima Yi had many wings at that time, and had formed a trend that could not be lost, only he could stabilize Cao Wei Jiangshan, but Cao Rui also reused the great general Cao Shuang, and his intention was obvious, that is, to let Cao Shuang balance Sima Yi.
With the death of Cao Rui, Sima Yi's life entered a new stage, and Cao Shuang continued to suppress him, and even adopted a strategy of rising and falling against him, appointing him as Taifu, thus depriving him of real power, and his situation was even worse.
At the most dangerous time, Sima Yi could only say that he could not get sick at home, so as to avoid being suppressed by Cao Shuang, but this was actually a kind of Taoguang and obscure strategy, and the reason why he did this was actually to turn himself into a master, because he was unwilling to put the fate of himself and his family in the hands of others.
Since the three kings of Cao Cao, Cao Pi, and Cao Rui were all uneasy about Sima Yi, he was already desperate for Cao Wei, and coupled with Cao Shuang's aggressiveness, he realized that there was only one way out for him, that is, a coup d'état to seize power.
However, Sima Yi's claim to be sick at home does not mean that he compromised and conceded defeat, he was actually actively planning and waiting for a suitable opportunity to launch a coup d'état.
In Sima Yi's view, Cao Shuang was not worthy of his name, although he held military power, but the prestige in the army was seriously insufficient, and he was very happy, often launched foreign wars, and could not win battles, causing the decline of national strength, not to mention, the generals were also dissatisfied because of heavy casualties.
Taking advantage of this opportunity, Sima Yi secretly co-opted many people, such as Shi Sunli, who was dissatisfied because Cao Shuang was poor and militaristic, and finally defected to Sima Yi.
In addition, Cao Shuang also had a monopoly on power, which caused dissatisfaction among the courtiers, and Sima Yi, as one of the victims, gained the sympathy of many ministers, who invisibly became his supporters, which was one of the reasons for the success of his later coup.
Of course, Sima Yi's son Sima Shiyin raised three thousand dead soldiers, which is actually an extension of Sima Yi's will, which also shows that at that time, within the Sima family, the coup d'état to seize power was already a consensus, but everyone tacitly agreed.
In 249, taking advantage of the opportunity of Cao Shuang taking Cao Fang out to worship his ancestors, Sima Yi launched the Gaopingling Rebellion, killing a large number of people led by Cao Shuang and severely cracking down on Cao Wei's staunch supporters, which were very cruel, full of intrigue and trickery, and were criticized by later generations.
After paving the way for posterity, Sima Yi died two years after the Gaopingling Rebellion, and through the efforts of his sons Sima Shi and Sima Zhao, by the time of Sima Zhao's son Sima Yan, he finally usurped Wei Jianjin and unified the whole country and became the ruler of the world.
After briefly talking about Sima Yi's life, let's talk about why Sima Yi did not cut Shu all his life after Zhuge Liang's death.
To sum up, there are three main reasons why Sima Yi did not cut down Shu:
First, from the perspective of time, Sima Yi did not have the opportunity to cut down Shu.
As I said earlier, after Zhuge Liang's death, Sima Yi had the idea of cutting shu, and his purpose was to continue to stay in the army, but Cao Rui saw through his ruse and transferred him to the capital.
Later, Sima Yi conquered Liaodong, and after pacifying Liaodong, Cao Rui died again, and was deprived of real power by Cao Shuang, and it was still difficult to protect himself, let alone cut down Shu.
After the change of Gaopingling, Sima Yi's work focused on purging the interior and laying a solid foundation for future generations, so Shu Was not considered.
Second, from a strategic point of view, the time is not ripe for cutting shu.
Sima Yi was a strategist, and he had a clear understanding of when to fight and when to keep peace.
When Zhuge Liang had just died, the reason why Sima Yi wanted to cut down Shu was selfish, in fact, there were also strategic considerations, after all, at that time, the internal turmoil in Shu Han was indeed a good time.
However, the Internal Stabilization of the Shu Han Dynasty was soon stabilized, and Liu Chan either suppressed or killed some people who affected internal unity, such as Yang Yi; and according to Zhuge Liang's instructions, he reused Jiang Wan, Fei Yi, Jiang Wei and others, and The Shu Han soon established a national policy of active defense against the outside world, recuperating internally, and developing the economy.
Therefore, the opportunity was fleeting, and after Shu Han had gained a firm foothold, it would be unwise to talk about cutting Shu again, and Sima Yi had a clear understanding of this, so he did not support Shu at all.
For example, in 244, in order to establish prestige in the army, Cao Shuang did not listen to Sima Yi's persuasion and insisted on leading his army to cut down Shu, but was defeated by Wang Ping, the general of the Shu army Zhenbei, with extremely heavy losses, and Cao Shuang himself almost did not return.
From this incident, it can be seen that Sima Yi's judgment is still correct, Shu Han is strong after recuperation, and Cao Wei is full of internal contradictions and cannot easily defeat the Shu state.
According to Sima Yi's vision, the most important thing for Cao Wei to do was not to hastily expand abroad, but to first clean up the threat from the north and actively develop its own strength, especially to vigorously develop agriculture and extensively carry out military tuns, and then formulate a strategy of cutting down Shu and cutting down Wu after accumulating enough grain and grass.
As early as Cao Cao's lifetime, Sima Yi had already put forward this strategy, Cao Cao was conscientious to implement, Cao Pi and Cao Rui also attached great importance to it, but Cao Shuang did not think so, he used his military strength for personal interests, resulting in a decline in national strength, and there was no strength to destroy Shu and destroy Wu.
Third, from a personal point of view, cutting shu was not in Sima Yi's interest.
To some extent, Shu Han gave Sima Yi a lot of "help", allowing him to save himself and develop his own strength.
As I said earlier, Sima Yi took the opportunity to fight with Zhuge Liang to make Cao Rui helpless against him, and he also took the opportunity to cultivate personal forces and firmly control the army in his hands.
After Sima Yi was transferred to the capital by Cao Rui, a cadre of soldiers led by Guo Huai remained on the border, all of whom were Sima Yi's cronies, and as long as Shu Han still existed, they could hold military power and become Sima Yi's strong backing.
However, once Cao Wei cut down Shu, the situation was different, and if it succeeded, Sima Yi and his cronies could be purged at any time; if they failed, Sima Yi's cronies would lose most of the half, and the impact on him would also be great.
Therefore, only if the Shu Han continued to exist, and Cao Wei continued to maintain a peaceful status quo, it was most beneficial to Sima Yi, and once he encountered major events, Sima Yi could also adapt to changes.
After the gaopingling rebellion, Sima Yi transferred Xiahou Xuan and Xiahou Ba to the capital (Xiahou Xuan entered the capital, but Xiahou Ba ran to shu Han), and then asked Guo Huai to succeed Xiahou Xuan as the general of Zhenxi, and the military forces of Liangzhou in Yongzhou were all over, and he immediately took control of the army (in fact, when Xiahou Xuan was the main general, the generals did not sincerely obey him, and Guo Huai played a very key role).
From this incident, it can also be seen that Sima Yi's layout in the army was not for the purpose of cutting Shu, but for self-preservation, and even preparing for the coup d'état to seize power, and it was not in his interest to cut down Shu.
Fourth, Sima Yi's pursuit of life led him not to choose Shu after Zhuge Liang's death.
To some extent, Sima Yi's whole life was "forced", he did not want to be an official, it was Cao Cao who forced him; he did not want to rebel, it was Cao Shuang who forced him; he did not even want to be a tyrant like Cao Cao, so after the gaopingling change, he opposed Cao Fang's appointment of him as a chancellor, and also refused to add jiuxi to the honor, and even a duke did not accept it.
So, what exactly did Sima Yi want?
It can only be said that although Sima Yi was not a loyal subject, the Cao family extremely distrusted him, leaving his family in danger at all times, and many things had to be done in order to achieve self-preservation.
That is to say, Sima Yi may not have any big ambitions at all, he did not want to claim the throne, and his coup d'état to seize power was only to achieve self-preservation.
Perhaps, it was not until the coup d'état seized power that Sima Yi had greater ambitions, but he had run out of time, so he just did some bloody things to clear the way for future generations.
Therefore, Sima Yi's pursuit of life, in chronological order, should first be a coup to seize power, and then compete for the world, if the coup is not realized, he will not cut down Shu, otherwise the end will be reversed.