Tell us what negative and positive impacts the Qing Dynasty's "closed-door policy" had on the development of our country?

The Qing government's closed-door policy lasted for nearly 200 years. It played a certain role in self-defense against the aggressive activities of Western colonists. However, being isolated from the world meant that it could not see changes in the world situation and did not respond in a timely manner. The policy of isolation cannot weaken the power of Western capitalist countries, but hinders its own development, causing China to lose the initiative in foreign trade, cutting off the flow of Chinese and foreign science and technology, and hindering the flow of foreign trade. It has hindered the development of productive forces and social progress, widened the gap between China and the West, made China gradually fall behind in the world, and created a situation where modern China was passively beaten.