Why Taiwan can define as a country?
Because a country will not be a country if it declines to be one. In the 1970s, Taiwan has always attended UN meetings as a representative of China (the representative of China is now Beijing). Furthermore, to be a country, recognition is needed (the other criteria stated in the Montevideo Convention as having a defined territory, permanent population, a stable government, capacity to enter into foreign relations, self-determination), so as long as Taiwan lacks the recognition to be a state on its own, it will not be one.
