Zhou Shizong Chai Rong chose to retake Youyun Sixteen Prefectures at the most ripe moment, at this time, because of the problem of heirs within the Khitans, the two families of Yelü Bei and Yelü Deguang fought for several years, which seriously depleted the national strength of the Khitans. The Khitan Emperor when Zhou Shizong regained Youyun Sixteen Prefectures was a well-known "Sleeping Emperor" in Khitan history, and he did not care about political affairs at all. By the time the Zhao Kuangyin brothers had completely unified the south and turned around to prepare to retake Youyun Sixteen Prefectures, the situation in the Khitan had changed significantly compared to before. First, years of infighting ceased, and the Khitan throne was now in complete control of the Jeroboam lineage. Second, the Khitan Emperor at this time was a famous sage in Khitan history and his successor, the famous Empress Xiao. Third, the Khitan strengthened their control over youyun sixteen prefectures, and for a combination of various reasons, it was much more difficult for the Northern Song Dynasty to capture youyun sixteen prefectures than in the Later Zhou Dynasty.
Chai Rong can unify the country and mountains by living for ten more years, and the glory of the early Tang Dynasty can be restored for more than twenty years, and his strategic boldness and strategy are better than Zhao Kuangyin's. The strategy of first restoring Yanyun is more courageous and visionary than Zhao Kuangyin's first easy and stronger. Yanyun was a barrier to resist the Liao, at that time it was only a dozen years after the fall of the Khitan jin, and the Battle of Gaoping made Chai Rong realize that the Khitan was the trouble of the heart, otherwise the main force would be transferred to the south to fight, and the Khitan iron rode a charge to Bieliang.
Chai Rong took Qin Feng into four states, strangled QinLing to block Hou Shu, collected the fourteen states of Huainan in the north of the Jiangsu River, and rejected the Yangtze River to defend the Southern Tang, all of which were preparing, and then he devoted all his efforts to recoverIng Yanyun, destroying the Khitan if he could destroy it, and could not extinguish the guard of Yanyun, and the Khitan also became a rabid dog outside the door, without the small role of cavalry superiority, fully grasping the strategic initiative, at this time, he waved the division to unify the Jiangshan, and then he used a country to send troops out of Yanyun to fight the dogs, how to fight, and then it was the desert north, the western region. Chai Rong's early collapse was a rewriting of history after all, but unfortunately, they have already recovered the three passes and three states. In fact, Zhao Kuangyin wanted to at least recover Yanyun, and in the end, Zhao Guangyi was defeated and demoralized, and the weak Song pattern was formed, and he had no choice but to plant mulberry yu along the Baigou River, could this stop the Khitans.
Both Chai Rong and Zhao Kuangyin had the strength to retake Youyun Sixteen Prefectures, but unfortunately their lives were too short. Zhao Guangyi did not have that skill, and he also killed his eldest brother (there is a great possibility). However, what should be said is that It is not that Zhao Song's short-sighted vision first south and then north, this depends on the situation at that time, from the perspective of our descendants, we feel that Zhao Kuangyin's strategy is problematic. After the Chen Qiao Mu Rebellion, Zhao Kuangyin first had to do to stabilize the domestic situation, drink a glass of wine to release the military power, and completely solve the problem of the division of the town since the Anshi Rebellion, and thus passed three years.
At this time, if you fight the Liao, the victory is good, then the defeat of this new dynasty will be over, at this time it coincides with the death of Hunan Zhou Xingfeng, and his son cannot control the people below to find the Song Dynasty for help, this kind of false way to destroy the matter, the heavenly opportunity to give you will also weigh the pros and cons to take the two lakes. Strategically speaking, Zhao Kuangyin had no problem, as a new regime would do so in that case, and in the later period, Zhao Kuangyin also had a premonition that his brother would be difficult to control, and the Northern Expedition would also involve a lot of obstacles. Zhao Guangyi greatly weakened the combat effectiveness of the Song army, and was no longer able to take back Youyun Sixteen Prefectures.
At the same time, we cannot say that Zhao Kuangyin's strategy was wrong, we can only say that the end of the Tang Dynasty and the Five Dynasties and Ten Kingdoms were tossed, the mountains and rivers broke people's hearts and scattered national strength declined, the Khitan in the north was strong, the southern separatist regime was not peaceful, and the risk of hastily attacking the Khitan was extremely high, and once it could not quickly break through the Khitan and was attacked by the north and the south, the unified regime that was not easy to establish in the Central Plains was bound to collapse and die without a place to die. The rebellion of the Five Dynasties will come again, the Zhao song regime first south and then north, the strategy of first easy and then difficult was relatively stable at that time, the Khitan development potential in the bitter cold land of the north was limited, and after the Zhao song pacified the south.
The development potential of the Central Plains and the south far exceeded that of the north, and the longer the time dragged on, the more unfavorable it was to the Khitans, and Zhao Songdang studied the early Han Dynasty to recuperate for decades, on the basis of strong economic strength and population, such as Emperor Wudi of the Han Dynasty abusing the Xiongnu, such as Tang Gaozong destroying Goguryeo, Fang was the best policy, but he did not think that the best policy was only half implemented, the unification of the country was not restless, eager to recover Youyan, and the fiasco at the Sorghum River was defeated, and there was no chance again.