> They are two separate countries now

No, they are not. The US legally recognized Taiwan (fka Formosa) as Chinese territory in 1943 and 1945 and legally recognized the PRC as the sole legal government of China in 1979, following a similar recognition by the UN in 1971.

https://www.congress.gov/crs-product/IF12503

There are only 11 countries in the world that recognize Taiwan as a sovereign entity and the largest are Guatemala, Haiti, and Paraguay.

https://en.wikipedia.org/wiki/International_recognition_of_T...