After Cao Cao pacified Hanzhong, his adviser Liu Ye pointed out: The lord originally raised an army of 5,000 soldiers to attack Dong Zhuo, defeated Yuan Shao, Liu Biao and others, basically unified Jiuzhou, threatened the world, and now captured Hanzhong. Liu Bei was also a master of the generation, deeply strategized, but his reaction was slightly slower, he had just seized the Shu land not long ago, and the people had not yet returned. Now that the lord has attacked Hanzhong, the Shu people are terrified, the situation is very unfavorable to Liu Bei, and if you take advantage of the unfavorable situation against Liu Bei to attack the Shu land, you will definitely be able to break through the Shu land. If Liu Bei had not been given a chance to breathe quickly, Liu Bei would have relied on Zhuge Liang, who was good at governing the country, Guan Yu and Zhang Fei, who were good at marching and fighting, to pacify the people of Shu and occupy the terrain that refused to defend the dangerous terrain, and then it would not be possible to attack. If you don't capture the Shu land now, you will definitely leave behind troubles.
Liu Ye's analysis is very reasonable, after learning that Hanzhong was captured by Cao Cao, the people of Shudi were indeed panicked, and the people of Shu Han had to panic a day that Cao's army had attacked dozens of times, and Liu Bei killed many people who preached that Cao Cao was coming to attack, but failed to make the People of Shu peaceful. If Cao Cao had followed Liu Ye's advice, perhaps he could have pacified Shu in one fell swoop. However, Cao Cao issued a message that "people are not satisfied with their suffering." Vested Long, Look back at Shu Ye? Sighing, he rejected Liu Ye's suggestion.
Cao Cao was determined to unify the world throughout his life, and two years after the capture of Hanzhong, he launched a large-scale attack on Sun Quan, so attacking Shudi without victory was definitely not because anyone had to be satisfied and could not get Longwang Shu or the like, and the real reason why he rejected Liu Ye's suggestion was because of his internal reasons. Fazheng pointed out:
Cao Cao surrendered Zhang Lu in one fell swoop, and Ding Hanzhong, instead of taking Tuba and Shu as a result, but staying with Xiahou Yuan and Zhang Hetun to guard, was also returned to the north, which was not his wisdom and lack of strength, and there would be worries within. - Romance of the Three Kingdoms
What internal worries did Cao Cao encounter at that time?
Since ancient times, the conflict between monarchy and power has been continuous, with the expansion of Cao Cao's power, his threat to the monarchy has become greater, and at that time the world has reached the point of knowing only Cao Cao, not knowing the emperor, Cao Cao's behavior, saying that it is good to say that it is "to serve the Son of Heaven to order not to be a subject", and to say that it is not good to say that it is "to blackmail the Son of Heaven to order the princes". Liu Bei nominally claimed to support the Han Dynasty, but he divided Jingzhou with Sun Quan without authorization, seized Yizhou, and later claimed to be the King of Hanzhong, without the consent of Emperor Xian of Han, the court of the Eastern Han Dynasty at that time existed in name only, and Emperor Xian of Han was just a puppet emperor.
Perhaps when Cao Cao welcomed Tianzi to Xuchang, Cao Cao established Zhi Kuang to support the Han Room, but as his merits grew, his ambitions continued to expand, even if he had no intention of becoming emperor, but his subordinates definitely hoped that he could be emperor, because once Emperor Xian of Han gained power, he would definitely purge Cao Cao's men, so cao Cao even if he had no intention of becoming emperor, at this time he was already involuntary, he must firmly grasp the power, otherwise his family, he would be implicated.
Although he did not claim the title of emperor until his death, shortly after Cao Cao's death, his son Cao Pi forced Emperor Xian of Han to give way, and almost did not encounter any resistance. Obviously, it was Cao Cao who paved the way for Cao Pi. During Zhuge Liang's first Northern Expedition, the people of the three counties of Longxi rebelled against the State of Wei in response to Zhuge Liang; during Guan Yu's Northern Expedition, Shi Huxiu of Jingzhou, who was an official of the imperial court, and Fu Fang, the Taishou of Nanxiang, surrendered to Guan Yu, and the crowds south of Xu Du responded. It can be seen that the Han Room "a hundred-footed worm is dead but not stiff", although it exists in name only, but there are still many subjects loyal to the Han Room.
The contradiction between the Cao Cao clique and the Xiandi clique has reached an irrefutable point, and the internal worries mentioned in the Fa Zheng 's Hanzhong Policy' are both irreconcilable contradictions between the Xiandi clique and the Cao Cao clique, and the xiandi clique once plotted to kill Cao Cao with a belt edict, but the matter leaked and failed. Cao Cao's revenge was also sharp, killing all the relevant personnel and their relatives and friends, and Emperor Xiandi's favorite Concubine Dong was not spared. While Cao Cao's army was out on the march, the Xiandi clique was preparing a new plan to seize power, and Cao Cao must return in time to preside over the overall situation in order to stop the conspiracy of the Xiandi clique. If Cao Cao wanted to attack Liu Bei, it was obvious that the war would not end for a while and a half, and it was more important to firmly grasp the control of the imperial court than to destroy Liu Bei.
bibliography:
Romance of the Three Kingdoms