They ruled China for 37 years. I'm sure they had diplomatic relations

Hong Kong should return to the Taiwanese government. The legitimate government of China

"Before the Nationalist government was ousted from the mainland, the Republic of China had diplomatic relations with 59 countries, such as Australia, Canada, Cuba, Czechoslovakia, Estonia, France, Germany, Guatemala, Honduras, Italy, Japan, Latvia, Lithuania, Norway, Panama, Siam, Soviet Union, Spain, the United Kingdom, the United States, and Vatican City. Most of these relations continued at least until the 1970s, and the Republic of China remained a member of the United Nations until 1971."