The Sui dynasty revitalized the Chinese economy by building the Grand Canal which transported goods across China and made it into an economic power. The Tang dynasty added judicious polices and more infrastructure which further grew productivity. It then leveraged on this achievement by embarking on a campaign of foreign conquest. It invaded and occupied Manchuria, the Silla kingdom in Korea, northern Vietnam and Tibet. It then revived the tribute system practiced by the previous Han dynasty in dealing with foreign neighbors. This system is centered on China's world view that it is the Middle Kingdom and is the destined lord and protector of inferior countries. The homage is more of ceremonial and had hardly any negative effects on countries. On the contrary, it was a convenient system of foreign relations that fostered trade and cultural enrichment to all.
Perhaps the greatest impact of China to its surrounding lands is its contribution to trade. As the largest and richest country in Asia, it was the source of new products and technologies that enriched all that came into contact with her. Her porcelains graced thousands of tables. Her metallurgy produced agricultural implements and military weapons. Her invention of gunpowder was instrumental in either war or keeping the peace by intimidation. The invention of printing techniques helped propagate her religion and culture. China also further increased Asian trade by improving on her naval technology and plying her own voyages to distant Asian countries. The foreign-friendly policy and econo-centric world view of the Song dynasty made China the economic leader of a prosperous and peaceful Asian region.
The heightened transportation and contact between Chinese and other peoples was a factor in the intrusion of China's religions of Confucianism and Buddhism. Scholars in Korea and Vietnam took interest and were responsible for these religions to also take root in their countries. These countries including Japan, still held fast to their native religions but gave also space to the Chinese ones which made the religious sphere of Asia heterogenous.