The ROC government participated in the 1943 Moscow Conference , the Dumbarton Oaks Conference , and the United Nations Conference on International Organization and was a charter member of the United Nations after participating in the alliance that won World War II . In 1949 , the Nationalists lost the Chinese Civil War in mainland China and retreated to Taiwan , Penghu , Kinmen and Matsu , forming a rump state . Despite the major loss of territory , the ROC continued to be recognised as the legitimate government of China by the UN and by many non-Communist states . In 1971 , the UN expelled the ROC and transferred China 's seat to the People 's Republic of China ( PRC ) . In addition to the recognition of the ROC by a majority of countries before UN Resolution 2758 , the ROC lost its membership in all the intergovernmental organisations related to the UN . As the UN and related organisations like the International Court of Justice are the most common venues for effective execution of international law and serve as the international community for states , a majority of the countries aligned with the West in the Cold War terminated diplomatic relations with the ROC and opened diplomatic relations with the PRC
United Nations Conference on International Organization
United Nations Conference on International Organization
Foreign relations of Taiwan