Changes: Since the mid-Ming Dynasty, China has been closed to the outside world and gradually isolated from the world; After the rise of western capitalism, colonists began to invade foreign countries.

It shows that China's comprehensive national strength was still relatively strong at that time, and the gap between the east and the west just opened; In order to safeguard the interests of the country and the nation, outstanding figures such as Zheng Chenggong led the military and civilians to loyally resist the invaders. Therefore, the country's strong comprehensive strength is the key to safeguarding national security and national interests; In the face of enemy aggression, we should dare to fight.