What is the relationship between the foreign policies of the Tang and Qing dynasties, the decline of the national movement and the different foreign policies adopted?

Similarity: the economic base determines the superstructure. National unity and political stability have brought important guarantees to the rapid economic development and prosperity. The enhancement of national strength will enhance the country's mentality of being a big country and enhance the country's desire to strengthen ties with the world. Therefore, both the Tang Dynasty and the early Qing Dynasty actively developed foreign exchanges and had frequent political, economic and cultural exchanges with the world. For example, during the Sui and Tang Dynasties, there were trade contacts with Silla, Southeast Asia, Central Asia, West Asia, Europe and Africa, and Silla, Japan sent overseas students to learn advanced culture. The Qing dynasty also opened to the outside world. Later, due to the harassment of Japanese invaders in the southeast and the invasion of Taiwan Province Province by Dutch colonists, they gradually closed their doors to the outside world.

The rise and fall of the national movement depends largely on the policies of the rulers. During the Tang Dynasty, frequent exchanges with other countries made China's advanced ancient scientific and technological civilization spread all over the world. Similarly, technology from other countries was introduced to China. Only communication can generate political vitality. Similarly, the blind and arrogant mentality of "China is rich in natural products and does not need to exchange needed commodities with other countries" in the Qing Dynasty also closed the door for the rulers. When the industrial revolution changed the social outlook, western European countries were satisfied with the self-sufficient small-scale peasant economy and rejected new technology, culture and ideas, so they gradually fell behind western countries in all aspects. As a result, when western countries forcibly opened the door of China with powerful ships and cannons, the natural economy collapsed and the country declined rapidly.

Based on the analysis of high school history, I hope it can help.