Zhao Bing had no choice but to stay away from the two young ladies. Nowadays, the army seems to be advancing rapidly, regaining lost territories. The situation is very good. The government and the country are still immersed in the excitement of regaining Lin'an, busy taking over the capital and renovating the palace and yamen to prepare for re-entering. However, he ordered the rebuilding of the palace hall and not to build a large amount of construction. In addition to the large amount of financial support, the reason for this is also the question of whether to move the capital. If it is moved to Jiankang, it would be in vain.
After a series of field investigations, Zhao Bing found that Zhao Gou chose to build in Hangzhou for a reason. Jiankang faced the Yangtze River directly. If the Yangtze River defense line was broken, Jiankang would not have a depth of defense and would fall. This kind of setback would often have a great impact on politics and military. What made him even more worried was that the Yangtze River defense line he wanted to build also had insurmountable hidden dangers.
The Yangtze River is the largest river in China, and its important strategic significance has been widely understood by our ancestors since ancient times. The Wu-Chu water war that broke out in the late Spring and Autumn Period had already vaguely included the struggle for control of the Yangtze River, but before the Three Kingdoms, it had never become a military boundary between the north and the south. The formation of the Yangtze River defense line was an inevitable product of the situation of the Three Kingdoms. The confrontation between the Three Kingdoms and the Jin and Wu was based on the temporary balance of strength and was inevitable for historical development.
In the situation where Wei was strong and Wu and Shu were weak, Wu and Shu must take advantage of the dangers, seek a balance line of strength between the two sides in military affairs, use the geographical barrier formed by huge mountains and rivers to make up for their weaknesses, and protect themselves. In the late Eastern Han Dynasty, the Yellow Turbans were in chaos, the world was in chaos, the Han Dynasty was in danger, and all heroes rose up. Sun Jian, Sun Ce and his son took advantage of the situation to seize Jiangdong. In the fifth year of Jian'an, Sun Ce was assassinated and told Sun Quan on his deathbed: "Encourage the virtuous and capable, and each one should do their best to protect Jiangdong." The establishment of Jiangdong became the foundation of the Sun Wu Group at that time.
Zhao Bing has always planned to occupy the south of the Yangtze River in Qiongzhou and then attack the Northern Expedition, so everything is based on this policy. He knew that in history, in addition to the Southern Song Dynasty he inherited, there was also Sun Wu during the Three Kingdoms period. Although it lasted for several generations, it was unable to save half of the country in the end. In addition to the political factors, simply considering the Yangtze River defense line simply from a military perspective is also in an extremely passive and dangerous situation.
The natural conditions of the Yangtze River meet the requirements of Eastern Wu to shield the east of the Yangtze River. Its main stream runs from the west to the east across central China, and the upper reaches run in the high mountain canyons of the Qinghai-Tibet Plateau and the dangerous Bashu land of the four barriers. The middle and lower reaches have wide rivers and deep waters, dense river networks, and hundreds of tributaries radiate north and south, becoming natural barriers. Cao Pi once lamented: "The sky is the distance between north and south!" The northern army cannot advance across the river while advancing, but must go through long-term preparations.
The good geographical conditions allowed the Eastern Wu to effectively prevent the enemy from crossing south by operating the Yangtze River defense line, achieving the effect of using the river, the Han Dynasty as the pond, the tiger minister Yi Zhan, and guarding along the river, and confronting Cao Wei for decades. Of course, it is necessary to garrison and operate a natural barrier that lasts thousands of miles to form a solid military defense line, and to have sufficient national strength and technical level.
From the perspective of river defense: First of all, guarding the river must not be left unattended. After the development of the Han Dynasty, Jiangdong increased its population and economic development. Faced with the long-term war and economic recession, the Eastern Wu had an economic foundation for separatist areas. More than 200,000 troops from the Eastern Wu ensured that all fortresses on thousands of miles of fronts had troops to defend. Sun Quan once said, "If you only defend Jiangdong, your troops will be sufficient." A separatist regime with a population of more than 2 million made it capable of building a large number of military projects and maintaining necessary expenses.
Secondly, guarding the river must not be without ships. The great development of shipbuilding technology in Qin and Han dynasties provided equipment support for the defense of the Dongwu River. The use of anchors, rudders, oars, sails, and the emergence of ship superstructures have increased the power of warships, increased mobility, and greatly increased the capacity of soldiers and weapons. Warships can use weapons more effectively, especially fire attacks and fire launchers. In addition, for Dongwu, the developed water system of the Yangtze River and the numerous ports, bans, continents, and turpies on both sides of the shore are easy to exert their advantages in water warfare.
Zhao Bing's first stage strategy was to adopt the strategy of limiting and protecting the rivers and protecting itself from the Eastern Wu, and then consolidating the Yangtze River defense line, and finally rushing troops to fight the northern expedition to restore the Central Plains. At present, the Jiangnan region was developed by the Sui and Tang Dynasties, especially after the Southern Song regime moved south, Jiangdong region had become the richest region in the country, and the population in Jiangnan was once over 100 million, which was much stronger than the economic strength of the Three Kingdoms period. He also had the most elite navy and sharp firearms that were at least a hundred years ahead of the previous period. The conditions for operating the Yangtze River defense line were still in place.
However, Zhao Bing was facing a much worse environment. In the past, Sun Quan and Liu Bei formed an alliance, so there was no need to worry about the enemy descending from the upper reaches of the river. Now, Sichuan in the upper reaches is still under the hands of the Yuan court, and he cannot recover Shu for the time being. In addition, the Yunnan region on the left wing is also the territory of the Mongolian and Yuan Dynasty. They can use the same tricks to attack the Jiangnan region from the side, so they will be forced to fight on two fronts and divide their troops to defend the Yunnan-Guizhou region.
In addition, the current Mongol Yuan suffered losses due to the failure of the continuous expeditions and his strength decreased. However, it should be noted that since Kublai Khan inherited the Khan throne, he deployed the most combative troops in the northwest to suppress the dissatisfied sect kings and protect the fundamentals of Mongolia. If the real gold can successfully succeed this time and coordinate the relationship with the various sect kings, he can free up his hands to transfer the army to Jiangnan.
However, Zhao Bing knew that the most urgent task was to establish the Yangtze River defense line. According to historical saying, the Yangtze River line could basically be divided into three major sections: the upper reaches is Yizhou, the middle reaches is Jingzhou, and the lower reaches is Yangzhou. The situation he faced was different from that after the southward transition, but it was similar to the Eastern Wu. It did not occupy Shu, but only occupied the middle and lower reaches of the Yangtze River. At that time, under the guidance of the national policy of "limiting the river and protecting ourselves", the Eastern Wu carried out comprehensive military defense of the Yangtze River and built a Yangtze River defense line running through the entire territory.
Zhao Bing has never used the ready-made things, and he also conducted in-depth research on this. The Yangtze River defense line of the Eastern Wu was bent on the sea in the east and blocked the dangerous block in the west. The Yangtze River controlled its districts and set up a governor's office along the river to be responsible for defense. The sea and the trench were the support of both ends of the defense line. With the power of the Wei Zhou army at that time, it was not enough to launch a large-scale attack from the sea. The coastal defense was relatively stable, and the trench was not necessarily reliable just like the situation he faced.
The winding Wushan Mountains are above 1,000 meters above sea level, connecting Daba Mountain in the north, separating Jingxiang and Bashu. The Three Gorges travel through it and rush out. Lu Ji described the terrain here: "The connection between the suburbs is the heavy mountains and the dangerous land has no long hub path; the river flows rapidly, and the water is difficult to shake." Between the mountains and steep mountains, the large troops cannot pass and unfold quickly, and the Bashu army is difficult to attack Wu by land.
However, in waterways, since the vegetation protection in the ancient Three Gorges area was good, there were not many dangerous shoals in the waterway: Qutang Gorge only had Qutang, Huanglong Ertan, Wu Gorge only had Xinbeng and Shimen, and Xiling Gorge not many dangerous shoals. Although the Three Gorges shipping is not mature, people can already travel smoothly. At present, Sichuan is still in the opponent, and the natural defense line between the upstream and the middle reaches is roughly in the area between the Three Gorges and Yiling, that is, Zhao Bing wants to try his best to seize Jiangling in Jingzhou. This will be the starting point of his own defense line.
In addition, the Eastern Wu set up military towns in all important strongholds on the Yangtze River defense line, and some places also set up military town governors. They successively set up more than 20 military town governors, most of which are located along the Yangtze River. Although the military town governors in the Yangtze River defense line of the Sun Wu are deployed in the area and stationed in the army, they are not isolated from each other. The entire defense line is not divided by the jurisdiction of the military town governors, but an organic whole. According to the needs of the war situation, the military town governors can sometimes take action alone, and sometimes several military town governors can act separately and support each other.
According to the national policy of protecting the Yangtze River and the military geography of the Yangtze River defense line, Zhao Bing believed that the dangerous places in the lower reaches of the Yangtze River were Xiling, Puqi, Wuchang, Wankou, Niuzhu, Ruxu, Jianye, etc. The strategic areas with overall significance were roughly focused on Xiling, Ruxu, Wuchang, and Jianye, which he was eager to occupy at present.
For the entire defense line, the most disturbing thing about the Sun Wu ruling group is that the enemy breaks through its upper defense line, rushes its troops eastward along the river, and advances along the water and land. In this way, "the danger of the Yangtze River has been shared with us", and the effect of the Yangtze River's natural barrier is suddenly lost, and the entire defense line is completely exposed to the enemy's military strikes. Therefore, Xiling, located at the western end of the Yangtze River defense line, became the first military center on the Yangtze River defense line thousands of miles.
Lu Xun once wrote a memorial to Sun Quan: The key points of Yiling are, even if the country's limits are easy to obtain, they are also easy to lose. If it is lost, it is not just a county, but Jingzhou is worrying. His son Lu Kang also believed that Xiling, Jianping, the country's vassals are in a lowland state and were affected by two enemy territory. If the enemy sailed along the river, traveled thousands of miles, and rushed to the sky, and then arrived suddenly, it was not possible to rely on other troops to save the collapsed county. This was an opportunity for the safety of the country, not just a small disaster for the invasion of the border. Given the important position of Xiling, Sun Wu stationed heavy troops here and set up a commander in charge of the generals, all of whom were famous generals to defend Wu.
As the first military governor of Sun Wu, Ruxu was another important military center with overall significance on the Sun Wu Yangtze River defense line. Ruxu originated from Chaohu, flowed southeast through Wuwei, and entered the Yangtze River in the east, and the entrance was Ruxukou. Protecting the river must fight for Huai, and heavy troops stationed in Ruxu, and attacking can be attacked and retreated. In terms of attack, Sun Wu's elite navy can leave Chaohu and attack Hefei.
Hefei was a must-fight place for Wei and Wu during the Three Kingdoms: Wu occupied Hefei, which could shake the Central Plains; Wei occupied Hefei, and Xu and Huai of Wu were not at peace. Therefore, the war between Wu and Wei was mostly concentrated on the struggle for Hefei. Ruxu was not only the main channel for Sun Wu to attack Hefei, but also a fortress to defend the Wei army from southward. If Ruxu was lost, Cao Wei could go eastward along the Yangtze River, and arrive in Jianye in the morning and evening, which was indeed a danger of Wu's destruction of the country.
Jianye was located in the rising land of Sun Wu, and was once the capital, and Wuchang was also the capital. Sun Wu ruled a solid foundation here, and the interests of the wealthy landlords in Jiangdong were also concentrated near Jianye. Moreover, the Yangtze River is wide and vast, located in the water town of the south of the Yangtze River, with rivers and berths crossing, and Jili Navy stationed. "There is more than a hundred miles of small river in Moling, and there is a police force that can install a large ship, so I can manage the navy."
However, Jianye is located in the lower reaches of the Yangtze River, far from the upper defense line. Once there is a policeman, it is difficult to provide timely reinforcements. Wuchang is blocking the middle end of the Yangtze River defense line of Sun Wu. It can rescue Xiling, or prevent Cao Wei from going south to plunder Nanjun; it can support military operations in Ankou, Ruxu, Niuzhu and other places; it can also lead troops through the Han River, go north to attack Xiangfan, and then shock the Central Plains.
Sun Wu relied on the dangerous places of the Yangtze River defense line and other important military towns such as Xiling, Ruxu, Wuchang, and Jianye to form a hub to support the Yangtze River. In addition, he also set up naval ships to cruise up and down the Yangtze River to prevent accidents. The entire Yangtze River defense line echoed up and down, and completed it in one go. He also deployed heavy troops along the Yangtze River, relying on the Yangtze River in its territory to form a defense line that cannot be easily crossed. In this way, Sun Wu was able to establish the country in the east, resist Cao Wei in the north, and resist Shu Han in the west. This Yangtze River defense line played an important role in Sun Wu's implementation of the national policy of "limiting the river and protecting himself".
However, Sun Quan was not completely willing to just "keep the Yangtze River East", and wanted to advance towards the north and compete for the Yangtze River. Of course, this also consolidated the meaning of the Yangtze River defense line. Historically, if the southern regime could not push the boundary to the Huaihe River, but instead trapped the Yangtze River, its situation would be very dangerous. At this time, it had only one line of defense. If the northern army broke through the Yangtze River, it would have to wait for death. If an effective defense line could be established in the Huaihe River area, the situation would be much safer.
If the northern regime wants to conquer Jiangnan, it will cost a lot to break through the first line of defense and then cross the waterways Huainan. This process will consume a lot of strength of the northern army. Sometimes, if they don’t do it well, they will have collective diarrhea. When they arrive at the Yangtze River defense line, it will be useless. Moreover, it is not easy for them to plan ships to cross the river on the spot after crossing the thousand-mile line of fire. At this time, the northern army often can only look at the beautiful scenery of the Yangtze River. When the weather is good, you may also see the Jiangnan girl on the other side, and then you can go home.
Therefore, the war between the Eastern Wu and the north basically occurred in the Huaihe River to the Yangtze River. The two sides repeatedly fought for several cities on the border, surrounded by trenches, flooded water, sabotaged, and counter-intervention, and used various bad ideas to hurt each other. Later, the Eastern Wu suffered a loss, and the border defense line slowly retreated to the Yangtze River area. The fall of the Jianghuai River led the Eastern Wu regime to implement a strategy of limiting the river and protecting itself, and the retreat of the defense line exposed the capital of the Eastern Wu Jianye (Jiankang), to the enemy.
Chapter completed!