In fact, in Battle of Red Cliffs, if Cao Cao suffered heavy losses, Sun Quan would have hit Xuchang Yecheng, breaking the power of Jun; It is precisely because Cao Cao lost little that he was able to maintain his strength. He was also able to make the Western Expedition to Ma Chao and Han Sui, and even cut Zhang Lu in Hanzhong, and then transferred troops to attack Ruzhou, which also proved his ability to make a comeback immediately. If Sun Quan really won the victory in Battle of Red Cliffs, he would not be stopped by the defeated troops deployed by Cao Cao. The reason why Cao Jun can't be defeated is that Sun Quan lost in Hefei, Zhang Zhao had a hard time in Dangtu, and Zhou Yu and Cheng Pu besieged Nanjun for more than a year.
As for Cao Cao's failure to capture ruxu, there are other reasons.
In the seventeenth year of Jian 'an, Sun Quan established a wharf in ruxu. It can be seen from the conversation of navy master Monroe and others that there were no wharf forts on both sides of the Yangtze River. Lv Meng is worried that if there is no dock, it will be too late to get near the water, let alone get on the boat at once. Therefore, building docks and strengthening fortifications can resist enemy attacks. Waterfront wharf, like a castle on land, can make it difficult for the enemy to attack the city. This kind of construction represents that Sun Quan began to build border defense facilities, so no matter how many troops there are, they can only look at the fortified city and sigh.
In the eighteenth year of Jian 'an, Cao Cao attacked ruxu, quoting the notes in The History of the Three Kingdoms, Biography of Wu Shu and River Table. Cao Cao rode 400,000 horses, while Sun Quan gathered only 70,000 troops. Fortunately, there are such docks that can be used for fighting. Whether Gan Ning attacked Wei Jun at night as a striker or Cao Cao attacked Sun Quan for a month, it could not be successful, but it can be seen that the attack was very difficult. However, it also shows the strength of Cao Cao. Chibi not only failed, but also dispatched troops immediately, and it also formed a siege. Realizing this, Sun Quan, after failing to attack Hefei, decided that he could never attack Wei again during the Northern Expedition.
Cao Cao did not come in vain. Cao Jun not only broke Sun Quan's camp in Jiangxi, but also captured Sun Quan's captaincy named Gongsun Yang. However, when Cao Cao saw that Sun Quan's ships, weapons, soldiers and troops were disciplined and respected, he knew that this well-trained army was hard to swallow without hard work. If the enemy is strong, avoid it, and then take the opportunity to map the south of the Yangtze River.
This sigh of crossing the river was later compared with Zhang Lushi's exclamation in Hanzhong: "People don't know their suffering, they have won their dragons, so look back at the evil of Shu!" It's just a series of setbacks. At this time, there are still eight years before Cao Cao's death. People in their sixties are still in the Western Expedition (Sun Quan is in the south of the Yangtze River, Ma Chao is in Guanzhong, Zhang Lu is in Hanzhong, Yuan Shao was in Ji You before, and Tao Qian and Lu Bu are in Yan Xu). If Cao Cao is ill at this time, it makes sense. The iron man's morale is already low at this time. At that time, the ambition was old and ambitious, but today, it is obvious that Cao Cao's physical and mental state is not so good. Compared with Liu Bei, he was six years younger than Cao Cao, but at the age of 6 1, he still led the army to personally levy Dongwu. It seems that Liu Bei is still more energetic.
Cao Cao should be so aggressive and not easily compromise if he broke the thieves in Dongwuyang with righteousness according to the standards of that year, or insisted on fighting hard to collect Lu Bu in Yanzhou. Ruyiwu is not a stronghold to attack. The new building has been built for a year, and Sun Quan is helpless and worried about the city. If Cao Cao is a few years younger, will Pi City be flooded again and repeat the history of being besieged but capturing Lu Bu alive? Gongsun Zan once built the Yijing Yao Village, which was surrounded by numerous ravines and even accumulated three million welcome valleys, but it was still broken by Yuan Shao. Judging from the historical cases of Xiapi and Yijing being breached, no matter how strong the dock is, there is no chance to crack it. How about a year of encirclement? What is the strategy of imprisoning Sun Quan for one year and sending troops to attack all parts of Soochow? But maybe Cao Cao didn't have time to stay in Ruxuwu for a year because of health problems, so he had to give up the siege.
When Cao Cao attacked ruxu Dock, he also had superior forces than Sun Quan, and the conditions were very good, so it was not impossible to fight. Later, Wang Jun became active. Although he led the northern army, although he was 70 years old, he did not hesitate to attack Wu Dong, who was good at water fighting, with naval vessels, so that nothing is difficult in the world. Cao Cao's repeated retreat after the failure of crossing Chaohu Lake four times may really be related to Cao Cao's own health problems, so he had to return to recuperate. In fact, Cao Cao died of illness in a few years, and it is not an exaggeration to say that he was ill in his later years.
Therefore, Cao Cao's poor personal health should be the main reason why he could not play his early military level.