Taiwan is now a touchstone issue for the UK, the US and for us in China. This is how we see it | Zheng Zeguang

After Nancy Pelosi's visit to Taiwan, relations between the countries are at a delicate stage. There must be no miscalculation

• Zheng Zeguang is the Chinese ambassador to the UK
• Chinese ambassador warns UK not to cross red lines' over Taiwan

Over the past weeks, the world has seen the resolute response from China after the visit to Taiwan of US House speaker Nancy Pelosi. Some people have asked why this is necessary. To understand, one needs to learn some history.

Taiwan has been an inalienable part of China's territory since ancient times. Throughout history, the island has been twice lost and regained. During the colonial expansion of western countries, it was occupied by the Dutch for 38 years before it was recovered in 1662 by Chinese national hero Zheng Chenggong. When imperial powers were carving up the world among themselves, Taiwan was subjected to Japanese occupation for 50 years. The Cairo declaration of 1943 and the Potsdam proclamation of 1945 made it clear that Taiwan should be returned to China.

Zheng Zeguang is the Chinese ambassador to the UK