The reason why the three are called "natural hazards" is because of the rugged and broken terrain around them, which was originally a natural barrier to the south of Dingxiang.

In addition, it was a harsh winter, and the road was all buried by heavy snow, even the local residents who were familiar with the topography did not dare to travel easily, let alone the Tang army who went north from hundreds of miles away from the south! As for Li Shiji, he is still some distance from Dingxiang, and he is not yet a burning threat.

Jieli believes that the most important thing at present is to defend Chai Shao, which is approaching from the west.

Once Chai Shao crossed the river from the northeast corner of the loop, he entered the Baidao River.

Here is only more than 100 miles away from Dingxiang, during which a horse is flat, and it will not take a day to gallop, and you can enter Dingxiang.

At that time, Jieli, in addition to sticking to Dingxiang, actually had another choice: temporarily abandon Baidaochuan and retreat to the moraine between Monan and Mobei.

However, he had other considerations.

If it had been two or three years ago, he would have retreated without hesitation.

Because the Turks were strong at that time, even if the Tang army captured Baidaochuan for a while, it was difficult to hold it for a long time.

However, at this time......

In the Northern Dynasties, there was a "Song of the Emperor", which has been passed down to this day.

In order to boost the morale of the army, Gao Huan, Emperor Shenwu of the Northern Qi Dynasty, once ordered Prime Minister Hu Lu Jin to sing and personally sing harmony with him:

Eilechuan. Under the Yin Mountain

The sky is like a dome. Caged four wilds

The sky is firm. Wild

The wind blows the grass and sees the cattle and sheep low

In the song, "Eilechuan" is Baidaochuan, which is today's Tumochuan Plain, or Qiantao Plain, Hohhot Plain.

This is the Yellow River and its tributary Jinhe, that is, today's Dahei River, alluvial Pingchuan, vast territory, flat terrain, fertile soil, abundant water, relatively mild climate, is still the "rice grain river" of Inner Mongolia.

Since the Spring and Autumn Period and the Warring States Period, it has been an important stronghold for the struggle between the Chinese farming people and the northern nomads.

In the past few hundred years, this rich and beautiful Pingchuan has been passed through the hands of the Northern Dynasties and the Turks several times, and the strong ones have won it.

Although Turkic agriculture is not developed, the tribal economy still has to rely on this vast fertile field, where "the wind blows the grass and sees the cattle and sheep", like the wind and green waves.

Two or three years ago, when the Turks were strong, Monan and Mobei were under Jieli's control.

Under the circumstances at that time, if you retreat to the moraine in wartime, there will be the entire Mobei as a backing.

However, now, most of Mobei has fallen into the power of Xue Yantuo, and the northern Desire Valley Set, Tuo She, and Yantuo Set have all been forced to retreat to a narrow area at the northern foot of Yinshan Mountain, which is not enough to be used as a base for life and lessons.

What's more, the unusually cold and harsh winters in the past two or three years have made the Mobei environment even more unsuitable for survival.

Now, if the Tang Army is allowed to obtain Baidaochuan, Jieli knows very well that the chance of counterattack is extremely slim.

Recall that back then, after Jieli's father dyed and dried Emperor Wen of Sui Emperor Yang Jian as the Khan of Yili Zhendou Qimin, the Eastern Turks took Monan and Mobei as their basis.

In the past 30 years, after two generations of father and son, the four khans of Qimin, Shibi, Chuluo, and Jieli have been fighting and strategizing, and the country has been extremely prosperous.

Now that Mobei has been lost, if Monan is lost again, let alone counterattack, and even the bloodline and culture of the ethnic group, it will be difficult to inherit and continue.

When the time comes, it will be their turn to sing a sad song, "Kill me and make my six animals not rest; Losing my Bai Daochuan makes me have no color in history."

At this time, Jieli really has great pressure to survive, but fortunately, he still has more than 100,000 troops at hand.

According to his judgment, in addition to Chai Shao, Li Yaoshi, the closest to Dingxiang, was still three or four hundred miles away even if he crossed Luliang Mountain.

In the meantime, there are three natural hazards for its barrier, and there are storms and snowstorms for its barrier.

Jieli believes that no matter how Pharmacist Li uses his troops like a god, it is impossible for him to appear in front of his eyes in an instant.

Chai Shao led at most 20,000 soldiers, and in the past three or four months, this road of men and horses first took Shengzhou, and then crossed the river.

Pharmacist Lee's purpose was to induce Jieli to make such an erroneous judgment.

He sent someone to pass the news to Kang Sumi, so that he and other intelligence officers could make a message to Jieli, so Jieli transferred his main combat forces to the west of Dingxiang to resist Chai Shao's approach.

Pharmacist Li himself led 3,000 lightly armed cavalry, first across the cold and freezing Luliang Mountain, and then survived the frozen Shanyang Ridge and the Purple River, and quickly entered the Tun Evil Yang Ridge.

These 3,000 lightly armed cavalry were all the troops that Li Yaoshi could use.

Just because the purpose is to create the effect of "lightning speed", it is necessary to let all the soldiers ride their horses and gallop, which requires the dispatch of 3,000 war horses, 3,000 riding horses, 3,000 pack horses, and 1,000 pulling horses.

At that time, there were only 60,000 horses available in the entire territory of Datang! In addition to providing the operational dispatch of the six armies in the north, these 60,000 horses must also take into account the border defense in the west.

In this assault battle of Dingxiang, Li Yaoshi did not let Su Dingfang's Mo Dao team go along, because the heavy cavalry's armor and mounted horse armor were too heavy, and it was difficult to travel quickly to Guanshan.

He ordered Zhang Gongjin to command the rest of Dingxiangdao's troops, and together with Su Dingfang, he followed the 3,000 horsemen led by him to cross Luliang Mountain.

This way of employing troops is completely beyond Jieli's imagination.

Therefore, when he received the news that Pharmacist Li had led his army into Tun Evil Yang Ridge, he was completely incredulous! He decided that it was impossible for the Tang army to cross the three heavenly dangers so quickly under such weather, so he was unprepared.

In fact, this is the habit of the Tang Army's Shenwei Jingwu Gongjun, from Deng Shiluo in Shennongjia, Ran Zhaoze in Kaizhou, Xiao Milling in Shannan, and Fugong Qi in Jiangdong, to Jieli in Luzhou and Lingzhou, it has always been unexpected, but it seems to be reasonable.

Pharmacist Li knew that Jieli must have been shocked, so he asked Kang Sumi and others to speak, so that Jieli, who was already in a panic, believed that if it wasn't for the Tang Dynasty to come from the country, otherwise the dignified commander would never dare to rush into the army alone with only 3,000 lightly armed cavalry.

At this time, Dingxiang was in the west, and Chai Shao had already encountered a war with the Turks; Dingxiang Dongfang, Li Shiji's imminent message has also entered the Jieli tooth tent.

Pharmacist Li knew very well that he had to attack first before Jieli had a chance to deploy more troops and horses.

So he let the whole army rest for a day, and the next day Pingming deliberately released a rumor, making Jieli think that the Tang army was ready to attack.

The heavy snow solar term at 40 degrees north latitude is only dawn at the beginning of the morning, and the sun has set at the end of Shen.

Pharmacist Li only had 3,000 people, while the other party had tens of thousands.

Therefore, he had to bluff to make Jieli think that he was waiting for Li Shiji's army to arrive.

And the movement caused by Zhang Gongjin and Su Dingfang, including the heavy cavalry of the Modao team, through the mountains and streams, just made Jieli's scouts think that tens of thousands of military ranks were rushing away.