Why can't the powerful Tang Dynasty beat the weak Koguryo?

The prosperous Tang Dynasty stood at the top of the world in military, economic and cultural aspects, and was the most powerful country in the world. However, Liaodong area, which is extremely rich in various resources, has never been under the jurisdiction of the prosperous Tang Dynasty and has been occupied by North Korea all the year round. Liaodong area is recorded in Reading Historical Records? The forgiveness of salt and iron was widely expected? . Therefore, the kings of the Tang Dynasty all had the idea of destroying Korea and seizing Liaodong, but it was extremely difficult for the weak North Korea to let go. The war between the prosperous Tang Dynasty and Korea lasted for two generations of Tang kings for more than 20 years, and finally Korea was slowly killed by it. Why on earth did the powerful Tang Dynasty always defeat the weak North Korea?

First of all, Koreans were always on guard in the Tang Dynasty. Although they claimed to be courtiers of the Tang Dynasty, they not only obeyed the instructions of the Tang King, but also secretly guarded against the rebellion of the Tang King. In the weak years, North Korea built various powerful fortifications, which not only turned the city into iron barrels, but also built the Great Wall thousands of miles away, as recorded in the Book of the Old Tang Dynasty? It is more than a thousand miles from Fuyu City in the northeast to the sea in the southwest. . In the prosperous Tang Dynasty, it was not until 664 AD that North Korea began to fight, which gave North Korea sufficient preparation time.

However, the eastward expedition in the prosperous Tang Dynasty faced not only the fortifications built by North Korea, but also its natural geographical location. South Korea has two geographical defenses. One is the vast Liaohe River. No matter how powerful the army in the prosperous Tang Dynasty is, it will pay a painful price to strengthen the Liaohe River. Second, the weather, where Korea is located, is particularly cold in winter. So far, the expedition of the Tang Dynasty has not been able to fight a protracted war, and the weather has seriously reduced the advantages and strength of Tang Junban. Emperor Taizong's first personal expedition to North Korea failed because of bad weather. According to Zi Tongzhi Jian, Tang Jun's grass is dry and frozen, so it is difficult to stay. Emperor Taizong could only give up returning to the DPRK.

North Korea not only has advantages in fortifications, but also the Korean people are brave and good at fighting, and the Korean people almost never stop fighting. There are many ethnic minorities in Liaodong, but no one has the strength to unify them. Therefore, all ethnic groups are constantly fighting, and North Korea, as one of the most tenacious ethnic groups, is a soldier and a soldier is like a tiger. It can be said that South Korea itself is a nation born for fighting. In several wars with the Tang Dynasty, North Korean soldiers persisted and never gave up. Even though the Tang Dynasty was far superior to North Korea on the surface, it could not be defeated for a long time and was dragged to death by North Korea until it gave up.

Therefore, it is such a militant nation, coupled with strong artificial and natural fortifications, that can defeat the troops with weak capital in the prosperous Tang Dynasty under the extremely powerful offensive.