What is the significance of China's insularity?

Answer 1

After the Zheng He voyages in the 15th century, the foreign policy of the Ming Dynasty in China became increasingly isolationist. Hongwu Emperor was the first to propose the policy to ban all maritime shipping in 1371.[2] The Qing Dynasty that came after the Ming often continued the latter dynasty's isolationist policies. Wokou or Japanese pirates were one of the key primary concerns, although the maritime ban was not without some control.

At the end of China's bloody civil war, in the early and mid 1900s, the country quickly closed off its borders to many outside countries and only maintained diplomatic ties with the Soviet Union. For a period of time the Chinese attempted to become self reliant, but found that in doing so the country could not break even economically, especially when attempting to maintain a communist vision when it came to economics. In the 1970s the People Republic of China began large radical economic reforms, which forced the country from a zero competition nation to one of the most capitalistic in the world. In doing so it quickly began to open its borders to the trade of various other countries thus adding itself to a global trade economy. While the government still regulates many of the country's cultural interactions with others, it is very open to the concept of an open market and competition with other countries, allowing the flow of technological innovations to flow in and out of its borders freely.

http://en.wikipedia.org/wiki/Isolationism