To me, I see no reason to change national boundaries (e.g., merging China and Taiwan) unless there are really good reasons.
The thing is that almost all Chinese living on the mainland (and almost half in Taiwan?) don't see China/Taiwan as separate national boundaries. They believe in the "One China" principle and they see one country. (Of course the people in Taiwan believing in the 'One China' principle also believe the provisional situation must remain that way until circumstances in China change.)
Preferably, whether these reasons are good or not is a decision to be made by the people of the two countries involved, in a democratic way.
Again, only IF you accept the "two countries" assumption. Otherwise, you have the "one country, indivisible..." principle that every American schoolchild also recites. This is a view that goes deeper than just the PRC vs. ROC issue. The sacredness of national unity goes to the heart of modern Chinese nationalism and the anti-colonial struggle. That is why the KMT's successors on Taiwan have been so slow to jettison it.
Obviously, these are important indicia, but it's up to the people involved (the Mainlanders, the Taiwanese) to decide how distinct they are, in a democratic way.
But even under democratic principles, secessionism is often rejected once a national state is formed. [Of course whether the national state can enforce recognition of the national unity principle or not becomes a matter of cruel 'real-politik'.]
One thing that should be noted is that Taiwan has a "Formosan" (non-Han) population that the PRC lacks.
Not exactly true. 98% of the people of Taiwan are ethnic Han Chinese. The remaining 2% are indigenous people of about 11 groups from Austronesian/South Chinese origin. About 2/3rds of the population originated in Fujian Province (the province where the bulk of today's Chinese immigrants to the US come from); another group, called the Hakka, came from Guangdong; and about 15% are called "mainlanders" who came in 1949 from all over China. In practical terms this shared ethnic background really makes the situation different than Tibet or Chinese central asia.
The history since 1950 or so has been different, so that language, culture, traditions, etc. have not been parallel or converging.
It is a bit of a cliche, but in Chinese culture and their sense of identity 1950 is not far back.
Thomas Lepeardo
