During Zhuge Liang's first Northern Expedition, Wei Yan proposed the "Meridian Valley Conspiracy", which meant that as long as he was given 10,000 soldiers and horses, of which 5,000 elite soldiers, 5,000 were responsible for escorting grain and grass, within ten days he could directly insert himself from the Meridian Valley to Chang'an. On the other hand, Zhuge Liang led his troops north from the Xie Valley, so that he could take the area west of Xianyang in one fell swoop. How did Zhuge Liang react?
The Chronicle of the Three Kingdoms records: "Liang thought that this county was in danger, it was better to be safe from Tan Dao, and he could take the Long Right flatly, and the ten perfections would be overcome without worry, so there was no need to delay the calculation." Zhuge Liang thought that this plan was not appropriate and very dangerous, it was better to take the flat road safely, you can safely take the Long Right, there is a full certainty without any mistakes, so he categorically rejected Wei Yan's plan. Why didn't Zhuge Liang adopt the "Meridian Valley Conspiracy"? Is it really just this scheme that is dangerous? You must know that there will be dangers in fighting wars, and you have always paid attention to surprising victories. Zhuge Liang's Northern Expedition was to take Chang'an, and when Wei Yan proposed such a strange plan, why didn't he try it?
First, Zhuge Liang's strategic goals were incompatible with Wei Yan's machinations. When Zhuge Liang and Liu Beichu met, he had already planned very clearly: "If there is a change in the world, then order a general to send the troops of Jingzhou to Xiangwan and Luo, and the general to lead the people of Yizhou out of Qinchuan." From here, it can be seen that Zhuge Liang's strategic plan is very clear, and under the circumstances of changes in the world, troops will be sent from Jingzhou and Yizhou respectively. So what was the situation in the Shu Kingdom at this time? First of all, although Jingzhou belonged to the Shu Han Dynasty, it was later lost at the hands of Guan Yu, that is to say, Zhuge Liang's strategic plan of "ordering the general to send the troops of Jingzhou to Xiangwan and Luo" does not conform to this article. Secondly, Liu Bei had also died of illness after the Battle of Yiling, so it was naturally impossible for him to "lead the people of Yizhou out of Qin Chuan". Therefore, none of these conditions are satisfied.
Zhuge Liang's later strategic goal was to "set the Central Plains in the north, eliminate the traitors, revitalize the Han Dynasty, and return to the old capital." At that time, the capital of the Eastern Han Dynasty was in Luoyang, and the goal of Wei Yan's "Meridian Valley Conspiracy" was west of Chang'an, and it could not be "returned to the old capital", let alone revived the Han Dynasty. At that time, the situation was already very clear, Shu Han was the weakest, and Cao Wei occupied almost two-thirds of the world, and it was obviously impossible to achieve Zhuge Liang's strategic goals by Wei Yan's strategy alone. Therefore, in the absence of his own strategic goals, Zhuge Liang did not adopt Wei Yan's strategy.
Second, Zhuge Liang's Northern Expedition was no secret to Cao Wei. Generally speaking, the ultimate conspiracy is "strange" and "unexpected", but when Wei Yan proposed the strange plan, Cao Wei was already aware of Zhuge Liang's plan. In the edict promulgated by Liu Chan Jianxing in the fifth year, the goal of the Northern Expedition of the Shu State to "restore the old capital" had already been made clear to the world. Moreover, from the time Zhuge Liang led a large army into Hanzhong to the time of holding a military conference, there was a full 9 months before and after. For such a long time, Cao Wei must have already made all the preparations, so Wei Yan's strategy could not give the enemy a surprise attack. Even if the plan is very careful, it will be greatly reduced. Therefore, if he could take a surprise attack in Cao Wei's completely unprepared state, there might be some chances of victory.
Third, Wei Yan looked down at Xiahou Shu. The reason why Wei Yan dared to boldly propose the "Meridian Valley Conspiracy" was because he thought that Xiahou Shu was a waste of firewood. As long as he led his troops forward, Xiahou Shu would definitely be frightened and flee. In the Romance of the Three Kingdoms, Wei Yan said to Zhuge Liang: "If you hear about it, you will flee by boat." But did Xiahou Shu really have such a nest? Of course not, the Romance of the Three Kingdoms records: "There is no martial strategy in the nature of the dragon, but it is good to govern life... After that, the group of brothers did not obey the etiquette, counted the responsibilities, and the brothers were afraid to see the cure. From this, we can see that although Xiahou Shu is not very good at using military strategy, he loves management and management, and is not a useless person who only knows how to eat the old. Moreover, when Xiahou Shu saw that his brothers did not obey the etiquette, he repeatedly reprimanded them severely, indicating that he was a person who attached great importance to the etiquette and law. Obviously, it would not be to the point where, as Wei Yan said, "If you smell the delay, you will flee by boat."
Moreover, even if Xiahou Shu could not fight a war, there were still tens of thousands of soldiers stationed there in Chang'an City, and coupled with the strong defense of Chang'an City, no one could attack it. Taking a step back, even if Xiahou Shu's nest was destroyed, there would be Guo Huai and Cao Zhen behind him. Therefore, Wei Yan's plan looked very peculiar, but if it was really used, the effect would be another matter.
Fourth, Zhuge Liang was cautious by nature. Zhuge Liang decided not to adopt Wei Yan's strategy, and another reason was that he thought that Wei Yan's strategy was unreliable and too risky. You must know that Shu Han was originally a weak side, and it was difficult to gather these 100,000 troops, and if there was any mistake, wouldn't it increase the burden on the weak Shu Han disciples? Therefore, with Zhuge Liang's always cautious character, he absolutely did not dare to take this risk.
Why did Wei Yan propose the "Meridian Valley Conspiracy"? Quite simply, it's about wanting to make a difference. In the Chronicle of the Three Kingdoms, there is such a record about Wei Yan: "The generals are different in ordinary days, and the theory of the time must be replaced by light." That is to say, Wei Yan seemed to many people at that time that he would take Zhuge Liang's class in the future. Wei Yan's ability was beyond doubt, but if he wanted to sit in Zhuge Liang's position, it was impossible to rely on ability alone, he had to have enough prestige and battle achievements. Otherwise, many people oppose you, even if you sit up, it will not last long. Therefore, Wei Yan wanted to establish a miracle through the Northern Expedition, only in this way could he pave the way for the future to sit as the supreme military commander of the Shu state. But in the end, reality joked with Wei Yan, and after Zhuge Liang's death, Wei Yan, instead of succeeding in taking his place, was eventually killed by Ma Dai and destroyed the three tribes.