[revealer]

On the basis of the One China principle, of which the US recognises that Taiwan is a part of China, then the Taiwan Straits should not be and is not international waters. This will be negated if US renounces the One China principle. However if this is done and following Taiwan declares independence war will break out in the Taiwan Straits.

Originally,  both CCP and ROC were co-existing in China before 1949 although they were rivals.  ROC retreated to Taiwan when CCP took over China.   They are still fighting today although some ROCs in Taiwan are thinking about declaring Taiwan independence.  They made attempts to amend the ROC constitutions but failed.   

CCP can claim Taiwan Straits and Taiwan belongs to them;  there is no reason why ROC cannot declare Taiwan Straits and China belongs to them.   Until ROC decided to amend its Constitution,  CCP and ROC will co-exist and remain the owner of China technically.

The US's older administrations recognised CCP to be the owner of China before;  the present administration change their stand wanting to support ROC.