Explain why China and Japan opened their borders

The Japanese government had always liked the idea of expansion. They were constantly trying to get China to agree with them about the Twenty One Demands. They either had to expand their borders or go to war. They did not want that. Japan was constantly growing industrially. They felt they had to expand their territories in order to obtain the resources they needed.

The United States and the Opening to Japan, 1853. On July 8, 1853, American Commodore Matthew Perry led his four ships into the harbor at Tokyo Bay, seeking to re-establish for the first time in over 200 years regular trade and discourse between Japan and the western world.

In China's modern day economic history the Open Door Policy refers to the new policy announced by Deng Xiaoping in December 1978 to open the door to foreign businesses that wanted to set up in China.