[cityhantam]

during the ching dynasty  in a treaty ceasefire agreement taiwan was given away to japan after a losing war.
japan ruled twn for ard 50yrs
then japan lost the 2nd ww2 n so taiwan was free from japanese occupation

anyway communist  china has never 1 day ruled taiwan
 on the contrary kmt ruled china before mao came to power

That treaty signed by official of Qing Dynasty is not recognised by winning nations of WW2.

In Taiwan's constitution, which is constitution of Republic of China, Taiwan is a province of China. 

China is China, regardless of the dynasty.