Why did the government in Taiwan permanent seat on the security council during the 1950?

Taiwan, officially known as the Republic of China (ROC), held a permanent seat on the United Nations Security Council in the 1950s due to its status as the legitimate government of China after the Chinese Civil War. Following the war, the ROC retreated to Taiwan, while the People's Republic of China (PRC) was established on the mainland. The United States and its allies continued to recognize the ROC as the representative of China in international organizations, including the UN, leading to its continued presence in the Security Council until 1971, when the PRC was recognized instead.