Zhao Hao's initial plan to attack Lianghuai was to lure the enemy deep and annihilate the two Mongolian capitals of Wanhu Prefecture stationed in the Lianghuai region, so as to win the strategic initiative and wait for an opportunity to seize Lianghuai. However, with the development of the war situation, he adjusted the battle plan in time, changed the strategy to seize Huainan, and pushed the northern front forward to the Huai River, so as to destroy the sharp sword hanging over his head and establish a bridgehead for the next step of seizing the Central Plains.

However, the war has developed to the present, Zhao Yu found that the Mengyuan side was weak in its northward strategic response, and even still had illusions about the Yuxi Timurid army going south, and did not actively send troops to intercept it, which made him find fighters from it. Its tentacles have extended to the Central Plains, threatening the Gyeonggi region of Mengyuan, and no matter how slow its reaction is, it will mobilize troops to intercept it.

At this time, the destruction of Wanhu Mansion, the capital of the Mongolian army in Shandong, Hebei and Wanhu Mansion in Huaibei, Henan, which was covering the Central Plains, was a foregone conclusion, and the only troops available to the Mengyuan side were the guards and pro-army guarding the Gyeonggi region and the army of the kings of the sects who stayed in the northwest grassland region. The army of King Zong is far away, and it is the end of the harsh winter, when the spring grass has not yet sprouted, the war horse has just experienced a harsh winter, and the body fat is exhausted, which is the weakest time of the year and the physical strength has not recovered.

In previous years, the grassland could also receive help from the imperial court, and some grain could be mixed with grass to feed horses, but after the loss of Jiangnan, this benefit was basically cut off. People can't eat enough, and horses can only starve, so horses with insufficient physical strength can't march long distances continuously, which means that it takes longer to dispatch the army of the king of Zong from the steppe to help. Then, in order to deal with the immediate crisis, the first choice of the Mengyuan side can only be the guards stationed in the economic area.

And this time Zhao Yu adopted the tactics of dividing and attacking together, and the battle line from Ezhou to Shanyang was thousands of miles long, and the corresponding Mengyuan side also had to divide troops to intercept and fortify everywhere, but he was afraid that all the guards and pro-troops would be mobilized, and the troops would still be stretched, just like ten bottles with only eight bottle caps, no matter how they were distributed, there would be loopholes.

In this case, Meng Yuan has not much choice, and can only play all the cards in his hand in advance. Then there is an inevitable problem - the emptiness of Gyeonggi. Zhao Yu thought about whether he could use the navy to carry the infantry army to drive directly to Dagu Village by sea, which was the predecessor of Tianjin, and was still called Haijin at the moment, and it was the transshipment center for transporting grain from the south.

If you can successfully land from the sea, then you can avoid many important towns on the road to the bottom of the capital, which is like entering an empty gate. And the strategic encirclement of the Mengyuan guards who came to the aid of Lianghuai, copied their back road, made it difficult for them to return home, and made the real gold flee back to the grassland. In this way, not only can the strategy of recovering the Central Plains be realized in advance, but also the enemy's life gate can be directly attacked, which can be called a strategic decapitation operation.

The idea was exciting, but Zhao knew it would be difficult to implement. First of all, the Great Song Dynasty did not make preparations for the recovery of the Central Plains at present, and it is unclear whether human, material and financial resources can support this plan; Second, logistical supply will become more difficult as the battle line is extended. Although some of the difficulties can be solved by sea, the time is affected by the trade winds, and only a few months can be used, and the winter trade winds are about to pass. Not only did the landing plan fail, but they also needed to open up the canal route if they wanted to get a stable supplement.

Moreover, taking a step back and saying that the above conditions are not a problem, there are also many difficulties from a military point of view.

At present, Zhao Hao's northward advance is implementing the tactics of separate attacks and combined attacks. In fact, everyone understands that tactics are like cold weapons such as bows, knives, guns, and hammers, some are suitable for long-range attacks, and some are suitable for close combat, each with its own merits, and there are advantages and disadvantages.

The advantages of the tactics of separate advance and combined attack are: First, it can effectively contain the enemy's forces and make the opponent overwhelmed, which is the core and soul of the tactics of separate advance and combined attack. Second, it can confuse the enemy's attention, widen the width of the enemy's defensive front, force the enemy to dilute the defensive forces, and then create offensive opportunities. Third, it can enhance the mobility of its own troops and improve the reliability of logistical support. Fourth, all armies can take care of each other and avoid the danger of putting their eggs in one basket.

In addition, at this time, the means of command and communication in war are limited, the efficiency of long-distance logistics supply is low, and the supply output of a unit's geographical area also has a certain limit. However, this tactic also has disadvantages: first, it is inconvenient for command and coordination, and it is easy to scatter and cause chaos; In addition, the forces are scattered, which provides the opponent with various opportunities to break through.

Zhao Yu knew that in order to ensure victory in the war, it was necessary to grasp the principles of three aspects:

First, the ratio of troops should be appropriate and reasonable. Dividing and attacking together does not mean that the forces are evenly distributed, but that there are masters and slaves;

In both cases, the transition between primary and secondary should be flexible and flexible. Therefore, although the tasks of the various routes of our troops are different, under certain conditions, the partial division and the main force must also be flexibly converted, and strive to use the lever of "dividing and advancing" to give full play to the maximum advantages of each route.

Third, the cooperation of all roads should be compact and close. Dispersing forces is not arbitrarily divided. The troops of all roads either constitute strategic cooperation or campaign and tactical coordination, otherwise the scattered forces will become separate battles;

Fourth, the transition between offense and defense should be quick and resolute. Units of various routes that are divided into joint attacks sometimes have to rationally adjust their combat tasks in light of the change of the war situation, and when necessary, they even have to shift from an offensive state to a defensive state on the spot.

In short, the current implementation of the tactic of separate attack and combined attack is not only limited by command and logistical conditions, but also due to the lack of effective timing, communication tools, and terrain recognition means. Therefore, the victory or defeat of the tactics of separate attacks and combined attacks often depends on the ability of the commanders of the two sides and the front-line commanders to command and cooperate collectively.

Zhao Hao's plan to advance north this time was mainly divided into three routes, the goal of the Western Route Army was Xiangyang, the goal of the Middle Route Army was Shouchun and Zhongli, and the Eastern Route Army was Xuyi and Shanyang, which were very far apart and basically did not have the possibility of supporting each other. If the attack is too fast or too slow, it will cause the pace of the split attack to be disrupted, unable to cover each other's flank safety, and the enemy will take advantage of the loophole.

Because Zhao Yu knew that the most famous example of the failure of the tactics of splitting and attacking was none other than the battle between Ming and Houjin in the battle of Salhu. The Houjin army annihilated three of the four armies of the Ming army with inferior troops, so that the famous saying of Nurhachi that was circulating in the streets: "Ren Er comes a few ways, I only go all the way." Therefore, he strictly ordered all armies to strictly follow the predetermined battle plan, and not to change the established strategy according to their own will.

At present, the overall implementation of the plan is very smooth, and all ministries have fulfilled the set tasks. But Zhao Yu knows very well that there is a fatal flaw in it, and this flaw is in himself. In the whole plan, the Eastern Route Army was the most critical link, first of all, it was necessary to successfully lure the Yuxi Timurid Army into the trap, and secretly transfer its troops south to encircle and annihilate the enemy in the south.

At the same time, under the condition that the main force of the Eastern Route Army was transferred to the south, Zhao Yu should not only conquer Yangzhou City, but also annihilate the last living force in the Lianghuai region, and quickly occupy Xuyi and Shanyang, and then turn to the defense on the spot, intercept the aid of the enemy from Dadu, and buy time for the Annihilation of Yuxi Timur's army. Although he completed the task at the moment, he also understood that if the enemy army saw through his plan and the enemy concentrated his forces to attack the Eastern Route Army with all his strength, then there was a danger of collapse.

Although Zhao Yu was confident in the power of firearms, he did not think that he could resist the impact of 200,000 enemy troops with less than 20,000 troops, as long as he lost here, the enemy army would pour down like a flood, not only making the encirclement and annihilation of Yuxi Timur's army a pot of raw rice, but also enabling the enemy to detour back to the flank of the middle route army, forcing it to retreat. This also put the Western Route Army in danger, even if Xiangyang was captured, it would become an isolated city, repeating the mistake of being besieged and lost, so that the battle line was restored to the starting point.

It took so much manpower and material resources to win first and then lose in vain, a result that Zhao Hao couldn't bear. Not only will the accumulated savings of many years be exhausted, but it will also cause the main war faction to step down and trigger a new crisis in its own governance. So now, although Zhao Yu is close to the old capital and knows the huge political significance of recovering Bianliang, he does not dare to rashly cross the river and continue to march north, swallowing this fat into his stomach.

However, it is very simple to solve the crisis, as long as the main force of the Eastern Route Army led by Zhao Mengjin can destroy the enemy of Nandu before the enemy reinforcements arrive, and quickly come to help, the enemy army can only look at the river and sigh. And if the time is more sufficient, he can still have the spare strength to go to Bianliang for a walk, and by the way, he will pay homage to the ancestral tomb, and the benefits of this war will be enough for himself.

It's a pity that Zhao Yu doesn't know the strategy formulated by Meng Yuan at present, if he knows that Zhenjin has adopted Li Qian's advice, he is afraid that he is already happy at this moment, and he can't help but go deep alone. Because Li Qian's plan was based on the fact that Timur's army in Yuxi had been surrounded and annihilated, he regarded it as a dead man, and only wanted to block the Song army's continued northward advance, and abandoned the Huainan region, completely on the defensive, as if he was frightened!

Of course, this can't blame Zhao Hao for being cautious, and it can't blame Li Qian for being timid, because both sides are blind people at the moment - it's all guessing, and no one can accurately judge the opponent's next intention, so they both adopt conservative strategies and strive to be safe. But who knew that Zhao Hao still had a thought in his heart that made him itch unbearably, and he couldn't sleep well after being tortured, just hoping that time would pass slowly, the enemy reinforcements would come later, and the Jiangdong war would end sooner......