Although it was wise for Li Shimin's army to withdraw to Chang'an, it did not conform to the strategy of Emperor Li Yuan, and even made Li Yuan feel humiliated. Every time he advanced eastward, he was defeated by Zhang Xuan. The previous time was Hebei, but this time it was the Central Plains. Especially when the Central Plains had already won a great victory, Li Yuan felt even more frustrated.

Of course, Li Yuan also knew that the Sui army had launched a large-scale attack on Bingzhou. They not only occupied Hedong City and Pujin Pass, but also Shangdang County and Changping County. The situation in Bingzhou also made Li Yuan extremely anxious.

It is also for this reason that when Li Shimin returned to Chang'an, Li Yuan did not become furious, nor did he denounce Li Shimin for not following his will and evacuating from the Central Plains without authorization. Li Yuan also admitted that they had underestimated Zhang Xuan's determination to defend the interests of the Central Plains before.

The Wude Hall was particularly quiet. Li Shimin, Li Jiancheng and a group of important officials sat in awe. Emperor Li Yuan sat on the dragon couch and carefully read the text message Zhang Xuan wrote to Li Shimin. He seemed to want to see through the profound meaning behind each word. Indeed, some of the contents of this letter were very imaginative, such as "the whole country's forces attacked Guanzhong, and the troops were coming to Chang'an City", which demonstrated Zhang Xuan's ambition. For example, "The autumn harvest has arrived, and the food in southern Shanxi is sufficient", and it also hidden Zhang Xuan's desire for southern Shanxi.

After reading the letter silently, Li Yuan handed it over to the eunuchs next to him, "Passing it to the ministers!"

The eunuch first handed the letter to Prince Li Jiancheng. After Li Jiancheng read it, he handed it to Chen Shuda next to him. In silence, everyone finished reading the text message one by one.

"Tell me all my dear friends!"

Li Yuan's eyes fell on Pei Ji, suggesting that he would express his opinion first.

Pei Ji understood the emperor's suggestion, and he stood up and bowed: "I believe that Zhang Xuan's letter threatened more than the essence, and of course it also exposed some of his ambitions. It can even show some of his future plans. As for his threat to enter Guanzhong, we can pay attention to it, but we cannot take it too seriously."

"Don't forget Pei Xiangguo, Pujin Pass is still in Zhang Xuan's hands." Liu Wenjing next to him said coldly.

"Shangshu Liu is too arrogant!"

Pei Ji replied without hesitation: "Can you conquer Guanzhong by occupying Pujin Pass? Since that's the case, why did Zhang Xuan stop moving? Don't he know that he could destroy my Tang Dynasty by capturing Chang'an? Is it because Zhang Xuan is too stupid or is it that Liu Shangshu thought too much?"

Pei Ji's series of questions left Liu Wenjing speechless. At this time, Chen Shuda stood up and beat him up and said, "Don't argue for the first time. Let's discuss the matter and discuss how to resolve the current crisis in Bingzhou!"

The topic turned to the real issue, and Li Yuan nodded and asked Prince Li Jiancheng, "Let's talk about it too!"

"My son obeys the order!"

Li Jiancheng stood up and bowed to his father and ministers, and then said calmly: "I thought the crisis in Pujin Pass and Shangdang and Changping were one thing on the surface. It was Zhang Xuan who forced us to withdraw troops from the Central Plains. But if we think carefully, we will find that these are actually two things. Pujin Pass is just a temporary crisis, while Shangdang and Changping were an inevitable step for the Sui army to expand westward. Our threat is not in Pujin Pass, but in Shangdang."

"Brother, how can you see it?" Li Shimin asked in confusion.

Li Jiancheng smiled slightly, "So I said I should think about it. Last year, Zhang Xuan occupied Xipingguan and Huguan before signing the armistice agreement. It seemed to be to prevent us from experiencing the east, but if it was just to prevent the Tang army from experiencing the east, it would be enough for them to guard Weizeguan. There was no need to occupy Xipingguan and Huguan. This would cause us to be discomfort and eventually lead to us attacking Huguan. Zhang Xuan did not understand what he did not want others to do to others. There was only one reason for him to prepare for his attack on Bingzhou. In this letter—"

Li Jiancheng blew up the text message from Yang Zhang Xuan and continued: "South of Jinnan has enough food. From these four words he said, the biggest weakness of the Sui army is that it is insufficient food. He can now support nearly 300,000 troops, entirely because of the dividends he gained from the Goguryeo War, but the war dividends will be used up sooner or later. What should he do then?

He is planning ahead and seizing grain-producing land is his next plan. From the occupation of Yingchuan County, he can see his desire for grain-producing land. So I can be sure that Zhang Xuan’s next war plan must be Jianghuai and Jinnan, which are two grain-producing lands.”

Li Jiancheng's analysis was reasonable and had profound insights. Everyone agreed. At this time, Li Shimin pondered for a moment: "The emperor thought he would start a war on two fronts, but I think it is unlikely. With his current strength, he still cannot support the war on two fronts."

"This is the problem!"

Li Jiancheng smiled and said, "I also think he cannot support the battle on both sides. For example, the east and west sides start war at the same time. On one side is Goguryeo and on the other side is us. Zhang Xuan really cannot support the battle on both sides, but Du Fuwei is different. Does the emperor think he will raise the army of the country to attack Du Fuwei? Obviously not, but he cannot attack Du Fuwei and Bingzhou at the same time, so he occupied Shangdang and Changping and then adopted a defensive stance. As long as he does not attack Bingzhou in large quantities, the battle on both sides can still be done. This is why Zhang Xuan sent Yuchi Gong and Wei Wentong to Shangdang and Changping to Ping two counties. Both generals are known for their good defense."

Li Shimin pondered for a moment and asked again: "Why do you think the crisis in Pujin Pass and Hedong City will be resolved?"

"Send people to China to negotiate. Since the crisis in the two places is not the same thing, then Pujin Pass and Hedong City should be able to get it back through negotiations."

"If Zhang Xuan proposed to return the conditions for Pujin Pass and Hedong City to recognize Shangdang and the two counties of Changping return to the Sui Dynasty, what should we do?" Li Shimin asked incisively.

Li Jiancheng said slowly: "We hope that negotiations will resolve the problem. If the negotiations cannot be resolved, then the army should come on the stage. I believe the emperor is ready."

The final result of the court debate was a compromise proposal proposed by Chen Shuda. On the one hand, the envoys were sent to Zhongdu and asked the Sui army to withdraw from Pujin Pass and Hedong City. On the other hand, the Tang army actively prepared for war. Once the negotiations broke down, the Tang army immediately attacked Pujin Pass and used force to recover the lost territory.

Li Yuan accepted this plan, and he immediately appointed the Huangmen Minister Wen Daya as his special envoy to go to Zhongdu to negotiate the retreat of the Sui army from Pujin Pass and Hedong City.

Although he found a solution to Pujin Pass and Hedong City, Li Yuan was still worried about the Sui army's expansion of Bingzhou in the west. He returned to the imperial study room and immediately asked someone to find his two sons.

Soon, Li Jiancheng and Li Shimin hurried to the imperial study room.

"You two don't have to be too polite, sit down and talk."

The two brothers bowed and sat down. Li Yuan said slowly: "In the court meeting, I am afraid that you brothers will quarrel, so I suspended the follow-up discussion. But I am still worried about the recovery of Shangdang County and Changping County. There are only three of us father and son here. If you have anything to say, just say it first. Shimin will say it first! I see that you have been silent since then, and I guess you have reservations."

Li Shimin hurriedly said: "The dispute between Shimin and his elder brother is a dispute, it is a matter of business, but it will not affect the relationship between our brothers."

Li Jiancheng also said: "The second brother is right, father, don't worry about us."

"That's good!"

Li Yuan nodded with relief, "Since you brothers say that, I will feel at ease, Shimin will continue!"

Li Shimin continued: "I believe that my elder brother's previous views make sense. Hedongcheng and Shangdang County are indeed two different things, but that is just that Erchen is still in the Central Plains, and his state will change. When Erchen leads his army to withdraw from Guanzhong, his state has changed. Erchen is sure that Hedongcheng and Shangdang County have become one thing, that is, Zhang Xuan wants to gain a foothold in Bingzhou."

"What do you mean is that Zhang Xuan will always control Pujin Pass and Hedong City?" Li Yuan asked in confusion.

"Of course he wants to control Pujin Pass, but whether he can defend it still requires the strength of our army. What I mean is that Hedong and Pujin Pass are already part of whether the Sui army can defend Shangdang County. They will inevitably defend Pujin Pass and Hedong City to prevent us from attacking Shangdang County and Changping County. It is actually meaningless to send envoys to negotiate in Zhongdu."

"Why is it meaningless!"

Li Jiancheng said a little displeased: "Zhang Xuan violated the armistice agreement we signed last year. Of course, we should send people to Zhongdu to accuse him. Perhaps a hero like Zhang Xuan was disdainful of the agreement, but the ministers in Zhongdu may not think so. These ministers are all shameless people. Moreover, there are signatures of Su Wei and Pei Ju in the agreement. I believe that our literary attack will make Su Pei and others put pressure on Zhang Xuan and will achieve unexpected results."

Li Yuan praised Li Jiancheng's words very much, and he smiled gently at Li Shimin and said, "Shimin, your elder brother has experienced many years of hardship in Wagang Mountain. He is much more mature than you in terms of human nature and politics. In war, the emperor admitted that you are better than ordinary people, but in politics, you should still listen to your elder brother's advice more."

Li Shimin had no choice but to bow and said, "My father taught me the right lesson, but my son was really not considering the problem."

At this time, Li Jiancheng smiled again and said, "When it comes to Wagang Mountain, I can't help but get into old feelings. Can my second brother hand over Zhai Rang's army to me? It's really hard for me to give up this army."

Li Shimin was silent for a moment, "I'm going to tell you my brother that I plan to let the Wagang Army go to Badong to guard the town, and prepare for our second southern expedition in the future!"
Chapter completed!