In the Mongol-Jin War, in addition to the Defense Line of the Guanhe River and being able to confront the Mongols, the Jin State was basically incapable of resistance at other times, it can be said that since the beginning of Jin Xuanzong's southward migration, the Jin State has entered the abyss of destruction, and the military weakness of the Jin State is mainly concentrated during the reign of King Wei Shao, that is, the former emperor of Jin Xuanzong.

The Battle of Wild Fox Ridge, the main force of the Jin army suffered heavy losses, the military ability of the Jin State was hit, but there is still economic strength, as long as the situation is stabilized, the Jin State has the ability to gather troops again in the Mongol War, but at the end of the reign of King Wei Shao, in 1213 (the first year of Jin to Ning, the eighth year of Genghis Khan of Mongolia), Genghis Khan led a large army to the south, attacking the Central Plains and the land of Western Liaoning, destroying the economic base of the Jin State in the north, it can be said that during the wei Shao King, the Jin State did not have enough military economic ability to fight against Mongolia.
As the king of Wei Shao who witnessed the decline of the Jin Kingdom, he was born in the wrong era, if there is no strong foreign enemy in the Jin Kingdom, he will be a shoucheng king, he is a person who has no ability to govern the country and is not good at using people, the only praiseworthy thing is diligence and thrift, if there is a governance team to assist him, the Jin Kingdom can still maintain normal operation, but in the period of the rise of the Mongols, The King of Wei Shao can only take the Jin Kingdom step by step to decline, and lay the groundwork for the cruelty of being forced to the throne.
History of Jin. Wei Shao Wang Benji (Da'an 2nd year) In June, the great drought ... Bing Yin, earthquake... In July, the earthquake ... In August, the earthquake ... In September, the ground shook.
When looking at the "History of Jin", there is an allegorical record, that is, in the second year of Jin Da'an, that is, in 1210, that is, the year before the Battle of Wild Fox Ridge, which determined the most critical trend of the Mengjin War, there were earthquakes in the Jin Kingdom for 4 consecutive months, which was not a sign that the Mountains and Mountains of the Golden Kingdom were about to shake.
Although Genghis Khan established the Mongol state during the Jin Zhangzong period, but the Expansion of Mongolia was mainly during the wei shao king, if he was a capable and discerning emperor, the jin kingdom still had the opportunity to take advantage of the fact that the mongols were not yet strong, defeating this strong opponent, but the wei shao king did not have that interest.
The most representative event is that the Mongols first subdued the Western Xia before going to war with the Jin State, and the Western Xia asked the Jin State for help, after all, the Western Xia was originally subordinate to the Jin State, but the King of Wei Shao did not give military support, which made the Western Xia quickly fall to mongolia.
Yuan Shi. In the eighth year of taizu benji, Yelü Liuge established himself as the king of Liao and changed his name to Yuan Yuan.
Because of the combined force with Ye, the number of troops in a few months reached more than 100,000, and TuliuGe was made the marshal of the capital, the deputy of Ye, the camp tent hundred miles, and the Wei Zhen Liaodong.
At the same time, in the Mongol-Jin War, the Khitan people were mostly centrifuged from the Jin, when Yelü Liuge raised an army in Liaodong and was attached to the Mongols, and the power once developed to the extent that it was Yu Wanzhong, it can be said that in the war with the Mongols, the Jin State did not handle the relationship with the Khitans, and also accelerated the defeat of the Jin State.
In short, the Jin kingdom during the Wei Shao king period fell into a difficult period of internal and external troubles, in 1211 (three years of Dajin Da'an, six years of Genghis Khan of the Great Mongolian State), the main force of the so-called 450,000 Jin army was annihilated, the Jin state suffered heavy military losses, after which the Mongol army repeatedly went south to conquer the Jin state, of which the biggest blow to the Jin state was that in 1213 (the first year of jin to Ning, the eighth year of genghis khan of Mongolia), the three-way attack on gold led by Genghis Khan directly destroyed the economic foundation of the Jin state in the north.
Yuan Shi. Emperor Taizu Benji advanced to Huailai, and Jinxing Province completed Yan Gang and Marshal Gao Qizhan in battle, but was defeated and pursued to Beikou. Jin Bing bao Juyong.
In July of the first year of the Jin Dynasty, the Mongols went south again, when Genghis Khan led his troops in Huailai (present-day southeast of Huailai, Hebei) and Jinshan (present-day Yanqing, Beijing), defeated the troops of Yan Gang and Shuhu Gaoqi, and once again cried the capital of the Jin Kingdom, that is, today's background, in the face of the military disadvantage after the defeat at the Battle of Wild Fox Ridge, it was obvious that the Jin State did not seize about two years of precious time to rest, and did not build a sufficiently stable northern defense line.
After the Mongol army defeated the Jin army at the Battle of Huailai, the large army pointed directly at Juyongguan, as long as juyongguan was taken, the Mongol army could threaten Jinzhongdu, and there was a possibility of destroying Jin in one fell swoop, so the Jin army deployed heavy troops in Juyongguan, but the Jin army did not have the awareness of the overall defensive line, and only hoped to hold Juyongguan and force the Mongol army to withdraw.
It can be said that after the Jin people entered the Central Plains, they gradually developed the cavalry mobility tactics that they were good at in the early days of the founding of the country, and the Jin army wanted to repel the Mongol army by holding Juyong Pass, but Genghis Khan did not attack Juyong Pass, but took advantage of the time to attract the main force of the Jin Army, and sent a cavalry unit to carry out a great roundabout operation.
Yuan Shi. Muhua Li Biography attacked Yongguan, bijian, not allowed to enter, sent the Jianbei unified troops to Zijingkou, Jin Zuojian army Gao Qi led troops to refuse, and collapsed without a fight, so he pulled Zhuozhou.
Genghis Khan ordered Muhua Li to lead a long-range attack, through today's Laiyuan, Hebei, east out of Zijing Pass (northwest of present-day Yi County), to achieve a breakthrough in the weak defense of the Jin army, and the response of the Jin State was to shoot slowly, and when the gap reached the time when the Mongol army changed its route to Zijing Pass, then let the Shuhu Gaoqi lead the army to resist, it can be said that it is not to hold the dangerous place, fighting with the Mongol army in the plains, the Jin army has no cavalry troops to match it, and it is inevitable to be defeated.
This is what I said before, after the Battle of Wild Fox Ridge, the Jin Kingdom lost its elite main force, and did not seize the opportunity when mongolia temporarily had no full strength to go south to destroy Jin, did not establish a defensive line in the north that was enough to resist the Mongol southward movement, at this time do not hope to defeat the Mongol army in the field battle, the Jin army has lost its strategic initiative, the main defense is the way to survive, but when the Mongol army went south, the main force stuck to Juyongguan, but left a mouth in other places, why did the Mongol army think of things, Jin Jun did not think?
At this point in the development of the situation, Juyongguan has lost its original value, and when it is necessary for Jin Ting to make a rapid response, the "brain" of Jin Guo, which was originally slow to react, has instead confused itself.
King Wei Shao was not an emperor who was not good at using people, and at that time, the Jin general Hu Shahu escaped from the battlefield, and the ministers proposed to punish him, but King Wei Shao did not accept it.
History of Jin. Contrarian. The biography of Hu Shahu was finally used in Zhizhong, and he was given a gold medal, quan right deputy marshal, and the 5,000-strong Wu Wei army was tuned north of the capital.
Before the Mongol army went south, Hu Shahu was once again activated by King Wei Shao, and also commanded the Wu Wei army north of the city, which can be said to give an incompetent and ambitious general the right to fight, that is, in his own death, when Muhua Li led his troops to achieve a roundabout battle, Juyongguan was attacked and lost, and Jinzhong was in danger.
King Wei Shao may think that Hu Shahu's status is inseparable from his own support, so he should obey his own dispatches, and King Wei Shao ordered his troops to fight, but Hu Shahu did not have that loyal heart, first, he was afraid of the Mongols, and second, he did not want to give his life to King Wei Shao, so he simply joined forces with others to launch a coup d'état, kicked King Wei Shao off the throne, and supported Jin Xuanzong.
This is undoubtedly in the Mongol army when the city, the Jin people themselves stabbed themselves, originally in the face of the Mongol army to break through the Juyong Pass, the Jin State responded to the mistake, and now there is a coup d'état in Zhongdu, King Wei Shao was deposed, and then killed, jin Xuanzong, who had just succeeded to the throne, had the ability to control the overall situation and repel the Mongol army, so Jin Ting could only do one thing, that is, to stick to Zhongdu.
The zhongdu city was strongly defended, and the Mongols could not take it, but the problem was that the lack of strain in Jin Ting could not find a way to repel the Mongol army, and Genghis Khan did not stubbornly believe in whether Zhongdu was captured or not, but took a way to further weaken the Jin state.
Yuan Shi. Taizu Benji is the autumn, divided into three ways: order the crown prince Shuchi, Chagatai, Wokoutai as the right army, follow the Taixing and south... Emperor Hazar and Hu Chen Nayan, Humble Chi, and Bo Cha were the left army, obeying the sea and east, taking the counties of Jizhou, Ping, Luan, and Liaoxi; the emperor and the crown prince Tuolei were the chinese army, taking Xiong, Ba, Mo, An, and Hejian ...
The Mongol army divided into three routes and attacked the lands of Hedong, Hebei, Shandong, and Liaoxi in the Jin Kingdom, which was equivalent to cutting off the connection between Jinzhongdu and all parts of the north, and Zhongdu almost became an isolated city.
What is even more against the Jin Kingdom is that the Jin army is powerless to change this situation, all localities can only fight for themselves, few can resist the Mongol army, so the Mongol army said that it was to fight, not to say that it was to accept the dependence of various places, after raiding, the three-way Mongol army once again met under the zhongdu city, after this battle, the foundation of the Jin state's rule in the north began to waver, after all, whether it is the Mongolian support forces, or the forces that did not obey the Jin state, such as the Khitans, it can be said that Genghis Khan's three-way conquest strategy, Let the Jin Ting, who was hiding in the capital of Jinzhong, lose its ruling authority throughout the north.
At the same time, all parts of the north were looted by the Mongol army, and also lost a strong enough economic strength, if the Jin State in the north can establish a defensive line to curb the Mongol army from going deep into the Central Plains, then most of the area north of the Yellow River can still be blood transfused for the JinGuo War, but after the Mongol army retreated to the north, the Jin State that deviated from Germany did lose its ruling base in the north, so it is true that Jin Xuanzong moved south is a move to destroy the country, but it is also necessary to admit that it is very difficult for the Jin State to gain a foothold in the north. After all, the Mongol army could fight like this once, and it had the ability to fight a second time, and over time, even the strongest defense of zhongdu was useless.
In general, the Jin kingdom during the Wei Shao king's period in the Battle of Wild Fox Ridge, after encountering a serious military blow, did not form a defensive line in time that could effectively curb the Mongol army to the south, coupled with the fact that the King of Wei Shao had no talent for governing the country, and the use of people was improper, at the time of the crisis of the Mongol army, Hu Shahu, the general of the Wei Shao King,but dragged the Jin kingdom into the abyss again, Genghis Khan was also a temporary decision, choosing to further weaken the strategy of the Jin state, and the three-way Mongol army almost swept through most of the area north of the Yellow River in the Jin kingdom. Destroying the economic base of the Jin Dynasty in the north, there was no longer any capital to compete with the Mongols.
References to The History of Jin. Wei Shao Wang Benji", "Jin Shi. The Biography of Yan Gang", "Jin Shi. Contrarian. The Legend of Hu Shahu", "Yuan Shi. Taizu Benji", "Yuan Shi. The Biography of Muhua Li