What is history: it is the echo of the past to the future, the reflection of the future on the past. - Hugo
If nurhaci had learned to be a good citizen during the Zhu Di period, there would have been no chance of development and growth. Nurhaci's military strength was not strong when he started his army, and he did not have the strength to compete with the Ming army in Liaodong Province. Nurhaci's growth was the result of the acquiescence of the Ming Dynasty, when the Jurchens of Jianzhou were scattered, Nurhaci was only one of the small chiefs, and the Xihai Jurchens were controlled by the four major families, and in order to balance, the Ming Dynasty helped Nurhaci. Coupled with Nurhaci's bribery of Ming officials and generals, Nurhaci's growth was basically not much effort.
It was not until Nurhaci issued the Seven Great Hates that he officially broke with the Ming Dynasty. Only then did the Central Committee of the Ming Dynasty know about Nurhaci's ambitions. The Ming army at the Battle of Salhu was defeated miserably, lost the initiative, and shifted from active attack to defense. Nurhaci continued to grow and develop in Liaodong and constantly improved his political power. Even so, it was impossible to break through the Ming army's defenses. In front of the red-clad cannons of the Ming Army, they could not take advantage.
The end of the Ming Dynasty was mainly due to the rebellion of displaced people caused by internal affairs, not from the Jurchens outside the Guan, but in the end they were picked up by the backward Jurchens. The passivity of the Liaodong battlefield was also caused by the crisis of military generals caused by internal affairs.
During the Yongle period, the Ming Dynasty was full of civil and military generals, there was no infighting in the imperial court, the army's firearms and cavalry were skilled, and the field battles were fought by the Mongols who were riding and shooting, and the jurchens who were fishing and hunting could not resist it at all.